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PRINCIPLES  AND  PRACTICE 


OF 


Operative  Dentistry 


BY 
JOHN  SAYRE  MARSHALL,  M.D.  (Syr.  Univ.) 

DENTAL   SURGEON    UNITED   STATES    ARMY 
PRESIDENT   ARMY   EXAMINING   BOARD   FOR    DENTAL   SURGEONS 


PHILADELPHIA  AND  LONDON 

J.    B.    LIPPINCOTT    COMPANY 
1901 


COPYKIGHT,     1901 
BY 

J.  B.  LippiNCOTT  Company 


aUECTHOTYPED    AND    PRINTED    BY    J.    B.    LIPPINCOTT   COMPANY,    PHILADELPHIA,    U.S.A. 


^0  tbe  flUemoris  of  m^  more  tban  jFrienD 

THE  LATE 

DR.  JAMES  W.  WHITE 

EDITOR  OF  THE   DENTAL  COSMOS 

WHO    THKOUGH    THE    NOBLENESS    OF    HIS    CHARACTER    BECAME 

THE    INSPIRATION    OP    EVERY    YOUNG    MAN    WHO    CAME 

WITHIN    THE    SPHERE    OF    HIS    INFLUENCE 


THIS    TOLUME 


IS   AFFECTIONATELY    DEDICATED    BY 


THE   AUTHOR 


PREFACE. 


In  the  preparation  of  this  volume  the  author  has  kept  in  mind  the  needs 
both  of  students  and  of  practitioners  of  dental  surgery. 

It  has  been  his  endeavor  so  to  present  the  subject-matter  as  to  give  the 
student  a  comprehensive  view  of  the  principles  and  practice  of  operative 
dentistry,  arranged  in  a  natural  and  orderly  sequence.  This  plan  has  also 
been  carried  out  in  the  presentation  of  each  individual  topic,  in  the  hope 
that  the  student  will  thereby  be  helped  in  his  understanding  of  the  various 
phases  of  each  department  of  the  subject  and  likewise  taught  to  be  me- 
thodical in  his  studies  and  operations.  It  is  also  hoped  that  the  dental 
practitioner  will  find  in  the  work  material  which  will  assist  him  in  his 
investigations  of  those  jjathologic  conditions  of  the  teeth  and  their  con- 
tiguous parts,  and  the  surgical  methods  employed  in  their  treatment,  that 
occupy  so  large  a  part  of  his  time,  energy,  and  skill. 

The  methods  of  constructing  artificial  crowns  and  bridge- work  have 
not  been  included  in  this  volume,  because  in  the  opinion  of  the  author 
they  properly  belong  to  the  department  of  prosthetic  dentistry.  The 
subject  of  orthodontia  has  also  been  excluded,  for  the  reason  that  this 
branch  has  assumed  the  proportions  of  a  separate  specialty,  and  would 
therefore  occupy  more  space  than  could  be  given  to  it  in  a  work  of  this 
size  and  character. 

The  author  desires  to  acknowledge  his  great  indebtedness  to  his  friend 
Dr.  Vida  A.  Latham,  of  Chicago,  for  her  valuable  services  in  the  prepara- 
tion of  numerous  original  and  interesting  photomicrographs  of  normal  and 
pathologic  dental  tissues  and  of  bacteriologic  specimens  ;  also  to  his  friends 
Dr.  E-.  E.  Andrew^,  of  Cambridge,  Massachusetts,  and  Mr.  James  S. 
Shearer,  of  Bay  City,  Michigan,  for  the  use  of  a  number  of  original  photo- 
micrographs from  their  valuable  collections ;  to  Dr.  W.  D.  Miller,  of 
Berlin,  Germany  ;  to  Dr.  J,  Leon  Williams,  of  London,  England  ;  to  Dr. 
Filandro  Vincentini,  of  N"aple3,  Italy ;  to  Dr.  Matt  H.  Cryer,  of  Philadel- 
phia, and  to  Dr.  Frederick  B.  Noyes,  of  Chicago,  for  the  privilege  of 
reproducing  and  using  several  illustrations  from  the  published  accounts 
of  their  investigation^. 

The  author  also  acknowledges  the  courtesy  extended  by  Dr.  Wilbur  F. 
Litch,  Dr.  G.  V.  Black,  and  the  publishers  of  the  "American  System  of 


VI  PREFACE. 

Dentistry  ;"  by  Dr.  Edward  0.  Kirk  and  the  publishers  of  the  "American 
Text- Book  of  Operative  Dentistry ;"  by  the  late  Dr.  Henry  H.  Burchard 
and  the  publishers  of  his  "Dental  Pathology,  Therapeutics,  and  Pharma- 
cology ;"  by  Mr.  Charles  Tomes,  F.R.C.S, ,  of  London,  England;  by  the 
S,  S.  White  Dental  Manufacturing  Company,  and  by  others,  for  the  privi- 
lege of  reproducing  many  valuable  illustrations. 

Acknowledgment  is  also  due  to  his  friend  Dr.  Bertha.  E.  Bush,  of 
Chicago,  for  much  valuable  and  time-saving  assistance  in  reading  and 
correcting  the  proofs. 

Chicago,  August  1,  1901. 


CONTENTS. 


CHAPTER    I. 

PAGE 

Classification  and  Descriptive  Anatomy  of  the  Teeth 1 

Number  and  Classification  of  the  Teeth— Descriptive  Anatomy  of  the 
Teeth — Architectural  Design  of  the  Teeth — The  Incisors — The  Cuspids 
— The  Bicuspids — The  Molars— The  Deciduous  Teeth. 


CHAPTER    II. 

Origin,  Development,  and  Morphology  of  the  Teeth 26 

Evolution  of  Epithelial  Tissue — Evolution  of  the  Jaws — Evolution  of 
the  Teeth. 

CHAPTER    III. 

Histology  of  the  Dental  Tissues 34 

Enamel  —  Striae  —  Chemic  Composition  of  Enamel  —  Calcification  of 
Enamel — Stratum  Intermedium — Blood-Supply  of  the  Enamel-Organ 
— Dentin — Matrix — Dentinal  Tubuli,  Sheaths,  and  Fibrils — Interglobu- 
lar Spaces — Development  of  the  Root — Dentinification — Cementum — 
Cementification  —  Chemical  Composition  of  Calcified  Tissues  —  Nas- 
myth's  Membrane  —  The  Teeth-Pulp — The  Peridental  Membrane- 
The  Gums. 

CHAPTER    IV. 
Eruption  op  the  Teeth 59 

Deciduous  Teeth — The  Eruptive  Process — Growth  of  the  Jaw — Morbid 
Primary  Dentition — Exuviation  or  Shedding  of  the  Deciduous  Teeth — 
Eruption  of  the  Permanent  Teeth. 


CHAPTER    V. 
Bacteriology  of  the  Mouth 83 

Parasites — Classifications— Mouth  Bacteria  Proper — Bacteria  which 
affect  the  Integrity  of  the  Dental  Tissues — Sterilization  of  Hands  and 
Instruments — Technique  of  SteriHzation. 


CHAPTER    VI. 

Examination  of  the  Teeth  and  Mouth 107 

Position  of  Patient  and  Operator — Instruments  used  in  Examinations — 
The  Examination. 


VIU  CONTENTS. 


CHAPTER    VII. 

PAGE 

Dental  Caries 115 

Distribution — Results  of  the  Examination  of  Ancient  Crania — Preva- 
lence of  Dental  Caries— Etiology — Constitutional  Predisposing  Causes — 
Local  Predisposing  Causes. 

CHAPTER    VIII. 
Dental  Caries  (Continued) 135 

Theories  of  Caries — Caries  of  Enamel — Caries  of  Dentin — Penetration 
of  Caries — Caries  of  Cementum. 

CHAPTER    IX. 
Dental  Caries  (Continued) 161 

Varieties — Stages — Symptoms — Diagnosis — Prognosis. 

CHAPTER    X. 

Treatment  of  Caries.     Prophylaxis 166 

Cleanliness  of  the  Mouth  and  Teeth — Dentifrices — Aj|J;iseptics. 

CHAPTER    XI. 

Treatment  of  Caries  (  Continued) 171 

Medication — Excision. 

CHAPTER    XII. 

Treatment  op  Caries  (  Continued) 174 

Methods  of  Separation  of  Contiguous  Teeth — Exclusion  of  Moisture. 

CHAPTER    XIII. 
Hypersensitive  Dentin 184 

Causes  of  Hypersensitive  Dentin — Treatment— Palliative  Treatment — 
Chemical  Treatment — Heated  Air,  etc. 

CHAPTER    XIV. 
Cataphoresis 193 

Osmosis — Anodal  Electrolysis — Cathodal  Electrolysis — The  General 
Principles  or  Laws  which  govern  the  Generation  and  Transmission 
of  Electricity — Rheostats  ;  Current  Selectors  ;  Current  Controllers — 
Electrococaine  Anaesthesia — Method  of  Administration  —  General 
Anaesthesia. 

CHAPTER    XV. 
The  Classification  op  Cavities 217 

Simple  Cavities  upon  Exposed  Surfaces — Simple  Approximal  Cavities 
— Compound  Cavities. 


CONTENTS.  ■  ix 

CHAPTER   XVI. 

PAGE 

Pkepakation  of  Cavities 234 

Opening  the  Cavity — Removing  Decay — Retentive  Shaping — Forming 
Cavity  Margins. 

CHAPTER    XVII. 

Teeatment  of  Caries  by  Obturation,  or  Filling 250 

Filling-Materials  and  their  Introduction  —  Non-Plastic  Materials  — 
Physical  Characteristics  of  Gold  —  Properties  of  Gold-Foil  —  Non- 
Cohesive  Foil  —  Cohesive  Foil  —  Plugging  Instruments  —  Crystal  or 
Sponge  Gold  —  Gold-and-Platinum  Foil  —  Annealing. 

CHAPTER    XVIII. 

Considerations  in  Filling  Special  Classes  of  Cavities 272 

Simple  Cavities  upon  Exposed  Surfaces — Simple  Approximal  Cavi- 
ties— Compound  Cavities — Matrices — Tin-Foil — Tin  and  Gold — Finish- 
ing Fillings — Repairing  Defective  Gold  Fillings. 

CHAPTER    XIX. 

Plastic  Filling-Materials.     Amalgam 296 

The  Nature  and  Properties  of  Amalgam — Chemic  Relations — Com- 
position of  Alloys — Making  Dental  Alloys. 

CHAPTER    XX. 

Manipulation  and  Introduction  op  Plastic  Filling-Materials 321 

Especial  Uses  of  Amalgam — Mixing  Amalgams — Introduction  of  Amal- 
gams—Copper Amalgam — Gutta-Percha — Zinc  Cements — Varnishes. 

CHAPTER    XXI. 

Inlays 346 

Metal — Porcelain— Glass— Methods  of  Manipulation. 

CHAPTER    XXII. 

Denudation  or  Erosion  of  the  Teeth,  and  Attrition  or  Abrasion 359 

Causes — Pathology — Treatment. 

CHAPTER    XXIII. 

Diseases  and  Injuries  of  the  Dental  Pulp  and  Their  Treatment 373 

Hypersemia  of  the  Dental  Pulp— New  Formations — Calcifications. 


X  CONTENTS. 

CHAPTER    XXIV. 

PAGE 

Inflammation  of  the  Dental  Pulp 397 

Table  of  Inflammatory  Phenomena— Inflammation  of  the  Pulp— Sup- 
puration of  the  Dental  Pulp— Chronic  Inflammation  of  the  Dental 
Pulp. 

CHAPTER    XXV. 

Exposure  of  the  Dental  Pulp  and  its  Treatment 416 

Secondary  Dentin,  or  Dentin  of  Repair — Devitalization  and  Extirpa- 
tion of  the  Pulp — Physical  Effects  of  Arsenic  upon  the  Pulp. 


CHAPTER    XXVI. 

Pulpless  Teeth  and  Filling  Pulp-Canals  431 

Preparation  and  Treatment  of  Pulp-Canals — Materials  Employed  for 
Filling  Pulp-Canals  and  Methods  of  Introduction— Mummification  of 
the  Pulp. 

CHAPTER    XXVII. 

Bleaching  Discolored  Teeth 446 

Preparation  of  the  Tooth  for  Bleaching — Method  of  Bleaching — Chlo- 
rine Methods — Truman  Method — Dioxide  Methods — Sulphurous  An- 
hydride Method — Cataphoric  Method. 


CHAPTER    XXVIII. 

Diseases  op  the  Pericementum 459 

Pericementitis — Subacute  and  Chronic  Pericementitis — General  Non- 
Septic  Pericementitis — Tubercular  Pericementitis — Scorbutic  Perice- 
mentitis— Mercurial  Pericementitis. 


CHAPTER    XXIX. 
Dento- Alveolar  Abscess 474 

Causes — Varieties -Pathology — Formation  of  Pus — Location — Chronic 
Dento- Alveolar  Abscess — Treatment. 


CHAPTER    XXX. 

Replantation  op  the  Teeth 490 

Indications  calling  for  Replantation — Persistent  Alveolar  Abscess. 

CHAPTER    XXXI. 

Transplantation  and  Implantation  op  the  Teeth  494 

Transplantation  of  Teeth — Implantation  of  Teeth — Requirements  for 
the  Operation — Method  of  Operation. 


CONTENTS.  XI 


CHAPTER    XXXII. 

PAGE 

Dislocation  of  the  Teeth 501 

Partial  and  Complete  Dislocations — Treatment— Prognosis. 


CHAPTER    XXXIII. 
Fractukes  of  the  Teeth 505 

Simple,  Compound,  and  Comminuted  Fractures — Treatment — Union 
of  Fractured  Teeth. 

CHAPTER    XXXIV. 

Resokption  of  the  Roots  of  Permanent  Teeth 509 

Causes — Pathology — Symptoms  and  Diagnosis— Prognosis — Treatment. 

CHAPTER    XXXV. 

Hypercementosis 513 

Causes — Pathology — Inostosis — Symptoms  and  Diagnosis — Treatment. 

CHAPTER    XXXVI. 

Necrosis  of  the  Teeth 518 

Causes — Partial  Necrosis — Treatment. 

CHAPTER    XXXVII. 

Deposits  upon  the  Teeth.     Green  Stains.     Calcic  Deposits 521 

Composition  of  the  Saliva—  Salivary  Calculus— Varieties — Treatment — 
Scalers. 

CHAPTER    XXXVIII. 
Pyorrhoea  Alveolaris 530 

Constitutional  Origin  of  the  Disease— Local  Origin  of  the  Disease — 
Bacterial  Origin  of  the  Disease — Ptyalogenic  Calcic  Pericementitis : 
Causes — Pathology  and  Morbid  Anatomy — Symptoms  and  Diagnosis — 
Prognosis — Treatment. 


.     CHAPTER   XXXIX. 

Hematogenic  Calcic  Pericementitis 550 

Causes — Varieties — Pathology  and  Morbid  Anatomy — Symptoms  and 
Diagnosis — Prognosis — Treatment. 


CHAPTER    XL. 

Phagedenic  Pericementitis 568 

Causes — Pathology — Symptoms  and  Diagnosis — Prognosis — Treatment. 


xii  CONTENTS. 

CHAPTER    XLI. 

PAGE 

Anaesthetics,  Local  and  General  578 

Local  Ansesthetics — Anaesthesia  by  the  Local  Abstraction  of  Heat — 
Richardson's  Method — Letamendi's  Method — Anaesthesia  by  the  Local 
Narcotic  Effect  of  Drugs — Cocaine— Eucaine — Chloretone — General 
Anajsthetics — Nitrous  Oxide — Hewitt's  Method — Examination  of  the 
Physical  Condition  of  the  Patient — Precautions  against  Accidents— 
Administration  of  Ether. 


CHAPTER    XLIL 
Extraction  of  Teeth 595 

Indications  which  call  for  the  Extraction  of  Teeth — General  Condi- 
tions Unfavorable  to  Extraction — Instruments  used  in  the  Operation 
of  Extracting — Selection  of  the  Proper  Instruments  for  the  Extraction 
of  the  Various  Classes  of  Teeth,  their  Proper  Adjustment,  and  the 
Kind  and  Direction  of  the  Force  applied — Extraction  of  the  Roots  of 
Teeth — Difficulties,  Complications,  and  Accidents. 


LIST   OF   ILLUSTRATIONS. 

PLATES. 

PLATE  PAGE 

I.  Varicosed  enamel-rods,  magnified 36 

II.  Varicosed  enamel-rods,  very  highly  magnified  37 

III.  Normal  dentin  showing  tubuli  in  cross-section,  highly  magnified 44 

IV.  Normal  dentin  showing  tubuli  in  longitudinal  section,  highly  magnified 45 

V.  Leptothrix  racemosa,  early  stages  96 

VI.  Leptothrix  racemosa,  later  stages , 97 

VII.  Abnormal  root-canals 435 

FIGURES. 

FIG. 

1.  Vertical  section  of  inferior  maxilla  and  teeth  of  mole,  X  15 2 

2.  Deciduous  teeth  of  the  left  side 2 

3.  Permanent  teeth  of  the  right  side 2 

4.  Structures  of  a  tooth 2 

5.  Occlusion  of  the  teeth 3 

6.  Superior  left  central  incisor,  labial  surface 3 

7.  Superior  right  central  incisor,  labial  surface 3 

8.  Superior  left  central  incisor,  labial  surface 6 

9.  Superior  left  central  incisor,  lingual  surface 6 

10.  Superior  left  central  incisor,  mesial  surface 6 

11.  Superior  left  central  incisor,  distal  surface .  6 

12.  Superior  right  lateral  incisor,  labial  surface 7 

13.  Superior  right  lateral  incisor,  lingual  surface 7 

14.  Superior  lateral  incisor  with  exaggerated  cervical  ridge 7 

15.  Superior  right  lateral  incisor,  mesial  surface 7 

16.  Superior  right  lateral  incisor,  distal  surface 7 

17.  Inferior  right  central  incisor,  labial  surface 8 

18.  Infei'ior  right  central  incisor,  lingual  surface 8 

19.  Inferior  right  central  incisor,  mesial  surface 8 

20.  Inferior  right  central  incisor,  distal  surface 8 

21.  Inferior  right  lateral  incisor,  labial  surface 9 

22.  Inferior  right  lateral  incisor,  lingual  surface 9 

23.  Inferior  right  lateral  incisor,  mesial  surface 9 

24.  Inferior  right  lateral  incisor,  distal  surface 9 

25.  Superior  right  cuspid,  labial  surface 10 

26.  Superior  right  cuspid,  lingual  surface 10 

27.  Superior  right  cuspid,  mesial  surface ■. 10 

28.  Superior  right  cuspid,  distal  surface 10 

29.  Inferior  right  cuspid,  labial  surface 11 

30.  Inferior  right  cuspid,  lingual  surface 11 

31.  Inferior  right  cuspid,  mesial  surface 11 

32.  Inferior  right  cuspid,  distal  surface 12 

33.  Superior  right  first  bicuspid,  buccal  surface 12 

34.  Superior  right  first  bicuspid,  lingual  surface 12 

35.  Superior  right  first  bicuspid,  mesial  surface.  . . : 12 

36.  Superior  right  first  bicuspid,  distal  surface 12 

xiii 


XIV  LIST   OF   ILLUSTRATIONS. 

FIG.  PAGE 

37.  Superior  right  first  bicuspid,  morsal  surface 13 

38.  Superior  right  second  bicuspid,  buccal  surface 13 

39.  Superior  right  second  bicuspid,  hngual  surface 13 

40.  Superior  right  second  bicuspid,  mesial  surface 13 

41.  Superior  right  second  bicuspid,  distal  surface 14 

42.  Superior  right  second  bicuspid,  morsal  surface 14 

43.  Inferior  right  first  bicuspid,  buccal  surface 14 

44.  Inferior  right  first  bicuspid,  lingual  surface 14 

45.  Inferior  right  first  bicuspid,  mesial  surface 15 

46.  Inferior  right  first  bicuspid,  distal  surface 15 

47.  Inferior  right  first  bicuspid,  morsal  surface 15 

48.  Inferior  right  second  bicuspid,  morsal  surface 15 

49.  Inferior  right  second  bicuspid,  buccal  surface 16 

50.  Inferior  right  second  bicuspid,  lingual  surface 16 

51.  Inferior  right  second  bicuspid,  mesial  surface 16 

52.  Inferior  right  second  bicuspid,  distal  surface 16 

53.  Superior  right  first  molar,  buccal  surface 17 

54.  Superior  right  first  molar,  lingual  surface 17 

55.  Superior  right  first  molar,  mesial  surface 17 

56.  Superior  right  first  molar,  distal  surface 17 

57.  Superior  right  first  molar,  morsal  surface 18 

58.  Superior  right  second  molar,  buccal  surface 18 

59.  Superior  right  second  molar,  lingual  surface 18 

60.  Superior  right  second  molar,  mesial  surface 18 

61.  Superior  right  second  molar,  distal  surface 19 

62.  Superior  right  second  molar,  morsal  surface 19 

63.  Superior  right  third  molar,  buccal  surface 19 

64.  Superior  right  third  molar,  lingual  surface 19 

65.  Superior  right  third  molar,  mesial  surface 20 

66.  Superior  right  third  molar,  distal  surface 20 

67.  Superior  right  third  molar,  morsal  surface 20 

68.  Inferior  right  first  molar,  buccal  surface 20 

69.  Inferior  right  first  molar,  lingual  surface 21 

70.  Inferior  right  first  molar,  mesial  surface 21 

71.  Inferior  right  first  molar,  distal  surface 21 

72.  Inferior  right  first  molar,  morsal  surface 21 

73.  Inferior  right  second  molar,  buccal  surface 22 

74.  Inferior  right  second  molar,  lingual  surface 22 

75.  Inferior  right  second  molar,  mesial  surface 22 

76.  Inferior  right  second  molar,  distal  surface 22 

77.  Inferior  right  second  molar,  morsal  surface 23 

78.  Inferior  right  third  molar,  buccal  surface 23 

79.  Inferior  right  third  molar,  lingual  surface 23 

80.  Inferior  right  third  molar,  mesial  surface 23 

81.  Inferior  right  third  molar,  distal  surface 24 

82.  Inferior  right  third  molar,  morsal  surface 24 

83.  Deciduous  teeth  of  the  left  side 25 

84.  Graafian  follicles,  or  ova,  in  various  stages  of  development,  X  80 26 

85.  Division  of  mammal  ovum 27 

86.  87,  88.  Transverse  section  of  embryo  of  chick 26 

89,  90.  Vertical  sections  of  human  skin 27 

91.  Squamous  epithelium  from  buccal  cavity,  X  162 27 

92.  Longitudinal  section  of  lip  of  a  kitten 27 

93.  Transverse  section  of  hairs  of  scalp,  X  50 28 

94.  Epithelial  layer  of  the  mucous  membrane  28 

95.  96.  Columnar  epithelial  cells,  X  670  28 


LIST   OF    ILLUSTRATIONS.  XV 

FIG.  PAGE 

97.  Goblet-cells,  X  500 28 

98.  Section  of  jaw  of  rabbit  embryo 28 

99.  First  rudiments  of  a  hair  from  human  embryo 28 

100.  Lower  jaw  of  human  embryo,  X  80 29 

101.  Vertical  section  of  skin,  showing  bulbous  ends  of  hairs,  X  55 29 

102.  Head  of  human  embryo 29 

103.  Vertical  section  through  head  of  human  foetus,  X  80 29 

104.  Lower  jaw  of  human  foetus,  X  80 29 

105.  Involution  of  the  Malpighian  stratum 30 

106.  Lower  jaw  of  human  embryo,  X  75 30 

107.  Vertical  section  of  epithelial  cord,  or  primitive  enamel-organ,  X  300 30 

108.  Cross-section  of  epithelial  cord,  X  300 30 

109.  Primitive  epithelial  cord,  X  45 30 

110.  Section  through  lower  jaw  of  embryo  mouse 31 

111.  Evolution  of  dental  follicle  (ninth  week),  X  70 31 

112.  Developing  human  cuspid 31 

113.  Follicle  of  human  molar  (eleventh  week),  X  50 31 

114.  Human  embryo  (twelfth  week) 32 

115.  Vertical  section  of  human  molar  at  junction  of  enamel-organ  with  dentin 

papilla,  X  300 32 

116.  Vertical  section  of  incisor  of  human  foetus 32 

117.  Oblique  section  of  a  dental  follicle 32 

118.  Vertical  section  of  human  molar,  early  stage  of  calcification,  X  90 32 

119.  Vertical  section  of  cuspid  of  human  foetus,  budding  of  primitive  epithelial 

cord,  X  70 32 

120.  Vertical  section  of  human  foetal  maxilla,  X  70 33 

121.  Vertical  section  of  human  foetal  incisor,  X  50 33 

122.  Section  of  human  developing  tooth 33 

123.  Section  of  dental  folhcle  of  cat,  X  9 33 

124.  Vertical  section  of  cuspid,  human  foetus,  X  50 33 

125.  Vertical  section  of  molar,  human  foetus,  X  70 33 

126.  Section  of  dental  follicle,  first  layers  of  ameloblasts  and  odontoblasts,  X  100. .  34 

127.  Section  of  f cetal  femur,  showing  odontoblasts,  X  109 34 

128.  Forming  dentin,  showing  odontoblasts,  X  1900 35 

129.  Enamel-cells,  with  nuclei 35 

130.  Dentinal  sheaths 36 

131.  132.  Enamel-columns,  highly  magnified 36 

133.  Developing  molar,  ends  of  enamel-rods,  X  1000 36 

134,  135.  Sections  of  enamel-rods,  odontoblasts,  and  dentin 37 

136.  Section  of  enamel,  striations  of  Retzius,  X  HO 38 

137.  Section  of  dental  follicle,  first  layer  of  ameloblasts,  X  325 38 

138.  Teased  section  of  developing  molar,  showing  ameloblasts,  X  1000 38 

139.  Developing  enamel,  Tomes's  processes 38 

140.  Section  of  developing  human  molar,  X  1000 39 

141.  142,  Section  of  developing  tooth,  ameloblasts  highly  magnified 39 

143.  Transverse  section  of  developing  tooth,  X  275 39 

144.  Developing  tooth  of  embryo  lamb,  X  105 40 

145.  Section  of  human  foetal  incisor  ;  blood-supply  of  enamel-organ 40 

146.  Section  of  dental  follicle  of  rat,  papillary  layer,  X  90 40 

147.  Section  of  forming  enamel  (rat),  X  325 40 

148.  Section  of  incisor  of  rat,  X  80 41 

149.  Ground  section  of  developing  tooth  of  rat,  X  97 41 

150.  151,  152.  Forming  enamel,  calcoglobulin,  formation  of  enamel-rods 41,  42 

153.  Longitudinal  section  of  incisor 42 

154.  Longitudinal  section  of  inferior  molar 42 

155.  Section  of  root  of  bicuspid,  radiation  of  dentinal  tubuli 43 


Xvi  LIST    OF    ILLUSTRATIONS. 

FIG.  PAGE 

15G.  Dentinal  tubuli  at  dento-enauiel  junction,  X  760 43 

157,  158.  Sections  of  root,  parallel  to  dentinal  canals 43 

159.  Section  of  dentin  and  enamel,  tubuli  entering  the  enamel 44 

160.  Section  of  developing  tooth,  dentinal  fibres  passing  from  dentin  to  enamel, 

X  1000 44 

161.  Dentinal  sheaths,  X  273 45 

162.  Section  of  enamel  and  dentin,  interglobular  spaces,  X  50 45 

163.  Section  of  enamel  and  dentin,  interglobular  spaces,  X  HO 48 

164.  Section  of  dentin  and  cementum,  X  97 48 

165.  Section  of  enamel  and  dentin,  incremental  lines,  ,X  500 48 

166.  Vertical  section  of  foetal  face,  X  7 ■ 48 

167.  Section  of  human  lower  jaw,  X  9 49 

168.  Section  of  developing  human  cuspid,  X  100 49 

169.  Teased  section  of  developing  molar,  X  1000 49 

170.  Truncated  odontoblasts  and  fibril  cells 49 

171.  Section  of  tooth-follicle,  nuclei  of  odontoblasts,  etc.,  X  325 50 

172.  Odontoblasts 50 

173.  174.  Sections  of  bone,  X  60 51 

175,  176.  Sections  of  cuspidati,  magnified 52 

177,  178.  Sections  of  molars,  magnified 52 

179.  Section  of  root  of  tooth  and  alveolus,  X  80 53 

180.  Section  of  alveolar  process  and  cuspid,  X  100 53 

181.  Developing  bone  from  scapula,  X  50 53 

182.  Section  of  enamel  and  Nasmyth's  membrane,  X  250 54 

183.  184.  Sections  of  normal  pulp-tissue,  X  143 54 

185,  186,  187.  Sections  showing  blood-supply  of  the  pulp 55 

188.  Injected  dental  pulp,  X  8 56 

189.  Nerves  of  dental  pulp 56 

190.  Pericementum  and  alveolar  process  between  teeth,  X  100 56 

191.  Section  through  pulp-chamber  of  cuspid 56 

192.  Periosteum  surrounding  ulnar  and  radius,  X  13 • 56 

193.  194.  Peridental  membrane  of  forming  tooth 56 

195.  Section  through  alveolar  process,  X  30 57 

196.  Section  of  root  of  tooth  in  situ 57 

197.  Blood-vessels  and  nerves  entering  at  base  of  dental  follicle,  X  96 57 

198.  Section  of  pericementum  in  situ,  X  408 57 

199.  200.  Sections  of  peridental  membrane,  highly  magnified 58 

201.  Section  of  jaw  through  alveolar  process,  X  60 59 

202.  Section  of  dental  follicle  and  mucous  membrane,  X  26 59 

203.  Glands  of  Serres,  X  50 59 

204.  Epithelial  layer  of  embryonic  mucous  membrane 59 

205.  Section  of  jaw,  showing  forming  root,  X  15 60 

206.  Follicles  of  permanent  teeth  at  period  of  eruption  of  primary  teeth,  X  22 ...  .  60 

207.  Lower  jaw  of  foetal  mouse,  X  80 61 

208.  209.  Section  of  erupting  tooth  of  mouse,  area  of  resorption  at  cusp,  magni- 

fied     61 ,  62 

210.  Vertical  section  of  human  cuspid,  X  75 62 

211.  Kami  at  various  ages 63 

212.  Jaws  of  a  young  child 64 

213.  214.  Sections  of  jaw  of  embryo  cat,  showing  deciduous  tooth  and  follicle  of 

permanent  tooth 64 

215.  First  and  second  dentition 66 

216-220.  Eruption  of  teeth  71 

221.  Gum-lancet 72 

222.  Curved  scissors 73 

223.  Peculiar  exuviation  of  a  kitten's  tooth,  X  35 76 


LIST   OF    ILLUSTKATIONS.  xvil 

FI*'-  PAGE 

22-4.  Absorbent  organ  and  portion  of  dentin,  X  65 76 

225.  Calcification  and  decalcification  of  teeth 78 

226.  Fruit  mould,  X  130 84 

227.  Forms  of  bacteria 85 

228.  Various  forms  of  yeast  fungi 86 

229.  Torula,  or  yeast  fungi 84 

230.  Bacterium  typhosus,  X  1000 88 

231.  Bacillus  pestis  and  blood-cells  of  rat,  X  iOOO 88 

232.  Pneumococcus,  capsule  form,  X  1200 88 

233.  Diplococcus  pneumoniae,  X  1000 88 

234.  Streptococcus  pyogenes,  X  1000 89 

235.  Streptococcus  in  pyemia  after  erysipelas,  X  660 89 

236.  Bacteria  in  pus,  X  700 <  89 

237.  Bacillus  tuberculosis,  X  1000 89 

238.  Flagellated  spirillee  and  vibrio,  X  2100 90 

239.  Bacillus  of  hog  cholera,  X  1000 90 

240.  Staphylococcus  pyogenes,  X  1000 91 

241.  Streptococcus  pyogenes,  X  1000 91 

242.  Streptococcus  hominis,  X  21 8. 75 91 

243.  Leptothrix  buccalis,  X  193.75 92^ 

244.  Mouth  bacteria  (diplococci,  leptothrix) 92 

245.  Bacillus  buccalis  maximus,  1800  :  1 93 

246.  Spirochseta  dentium  (denticola)  and  leptothrix  threads,  X  1000 94 

247.  Spirochseta  dentium,  showing  flagella,  X  1000 94 

248.  Leptothrix  gigantea,  from  dog,  X  750 94 

249.  250.  Leptothrix  gigantea,  X  1000 95 

251.  Micro-organisms  from  enamel  surface 100 

252-258.  Leptothrix  racemosa,  fructification  heads,  etc 100' 

259.  Instrument-sterilizer , 105 

260,  261.  Dental  mirrors 105,  109' 

262-264.  Magnifying-glasses 110 

265.  Explorers Ill 

266.  Electric  mouth-lamp Ill 

267.  Parr's  universal  separator 112 

268.  Perry's  two-bar  separators 113 

269.  Syphilitic  teeth 129^ 

270.  271.  Caries  following  crack  in  enamel,  X  95 132 

272,  273.  Caries  of  enamel  and  dentin 156 

274.  Undermining  caries  of  enamel 157 

275.  Section  of  a  molar  crown  with  caries 157 

276-293.  Infected  dentin  and  dentinal  tubules 157-161 

294.  Section  of  a  molar  showing  stages  of  caries 162 

295.  Corundum  disks 173 

296.  297.  Tooth-separators 176 

298,  299.  Napkin  clamps 178 

300.  Rubber  dam  applied 180 

301.  Rubber-dam  holder 180' 

302.  Ivory  clamps 181 

303.  Ottolengui's  clamp  applied 181 

304.  How's  cervix  screw-clamp 181 

305.  Elliot's  clamp  and  forceps 182 

306.  Rubber-dam  applier ' 182 

307.  Ainsworth's  rubber-dam  punch 182 

308.  Sizes  of  holes  in  rubber  dam 183 

309.  Depressed  rubber  dam 183 

310.  311.  Denham  coffer-dam  shield 183- 


xviii  LIST   OF   ILLUSTEATIONS. 

FIG.  PAGE 

312.  Mirror 183 

313,  314.  Hot-air  syringes 189 

315.  Improved  electric  hot-air  syringe 190 

316.  Jewell  graphite  rheostat 205 

317.  Weston's  niillianipereoieter 207 

318.  Cataphoric  electrodes 208 

319.  Cataphoric  outfit  without  milliamperemeter 209 

320.  Arrangement  of  apparatus  for  cataphoric  work 210 

321.  Syringe  electrode 213 

322.  Flexible  face-piece  for  inhalers 215 

323.  Allis's  ether  inhaler 216 

324-344.  Simple  cavities  in  teeth 218-225 

345,  346.  Small  chisels  and  hatchet  excavators 226 

347.  Cavity  prepared  for  filling 227 

348,  349.  Cavity  near  morsal  edge  of  cuspid 227 

350-353.  Cavities  on  mesial  and  distal  surfaces  of  bicuspids  and  molars 228 

354-366.  Compound  cavities 229-233 

367.  Water-syringe 241 

368,  369.  Burs  for  opening  small  cavities 241,  242 

370,  375.  Cleavage  of  enamel 242,  249 

371,  372.  Chisels 242,  243 

373.  Excavators 245 

374.  Instruments  for  setting  screw-posts 248 

376.  Crowns  restored  with  cohesive  gold-foil 257 

377.  Cyhnders  of  gold-foil 258 

378.  Foil-carriers 258 

379.  Cylinders  and  mats  being  introduced  into  a  cavity 258 

380.  381.  Bing  pluggers  ;  Butler  pluggers 259,  260 

382.  Herbst  burnishers 262 

383,  384.  Varney  pluggers  ;  Webb  pluggers 264 

385.  Steel  mallets 264 

386,  387.  Darby-Perry  pluggers  ;  Chappell  pluggers 265 

388.  Royce  plugger-points 265 

389.  Snow  &  Lewis  automatic  plugger 266 

390.  391.  Abbott  automatic  mallet 267 

392,  393.  Bon  will  electro-magnetic  and  mechanical  mallets 267 

394,  395.  Electric  gold  annealers 271 

396.  Gum  retractor 272 

397-401.  Clamps  for  keeping  rubber  dam  in  position 272,  273 

402-411.  Filling  simple  cavities  upon  exposed  surfaces 273-276 

412-414.  Filling  simple  approximal  cavities 277,  278 

415-429.  Filling  compound  cavities 279-282 

430-433.  Matrices  and  forceps 284,  285 

434.  Hand-burnishers 288 

435,  436.  Engine-burnishers  ;  disk  burnishers 289 

437.  Plug-finishing  burs 289 

438.  Wood  polishing-points 289 

439.  Corundum  points  and  wheels 290 

440.  Arkansas,  Hindostan,  and  Scotcli  stones 290 

441.  Soft  rubber  i^olishing-cups 290 

442^44.  Plug-trimmers  and.  finishing  files 291 

445.  Right  and  left  plug-finishing  files 292 

446.  Thickened- rim  sand-paper  disks 292 

447.  Disk  mandrels 293 

448.  An  inoculated  gelatin  plate  showing  antibacteric  effects  of  copper  amalgam ...  313 

449.  Creager  loop  matrices 322 


LIST   OF   ILLUSTRATIONS.  xix 

TIG.  PAGE 

450.  Flagg  wafering  pliers 324 

451.  Glass  mortar  and  pestle 324 

452.  453.  Amalgam-carriers 326 

454.  Flagg  amalgam  instruments , 326 

455.  Kirk's  instruments  for  plastics 327 

456.  Revised  set  of  amalgam  instruments 327 

457.  Heating  spoon — cone-socket  handle 329 

458^61.  Built-up  molar  crowns 330 

462.  Flagg' s  gutta-percha  softener  and  tool-heater 354 

463.  How's  thermoscopic  heater 335 

464.  465.  Glass  mixing-slab  ;  spatulas 338 

466.  Details  of  process  for  making  cast  filling  for  incisor 347 

467^70.  Restoration  of  incisors  and  molars  by  cast  fillings 348 

471,  472.  Bridge-work 349 

473,  474.  Porcelain  stoppers  ;  inlay  rods 350 

475,  476.  Inlay  trephines  and  burs 351 

477,  478.  Electric  oven  ;  electric  furnace 352 

479,  480.  Erosion  of  teeth 365 

481,  482.  Erosion  of  teeth  from  gout 366 

483.  Abrasion  by  tooth-brush 371 

484,  485.  Hypersemia  of  dental  pulp 380 

486.  Secondary  growths  in  pulp-chamber 390 

487,  488.  Secondary  dentin  on  wall  of  pulp-chamber,  X  100 390 

489.  Secondary  dentin  in  base  of  pulp-chamber,  X  50 391 

490,  491.  Pulp-nodules ' 391 

492.  Section  of  pulp  with  pulp-nodule,  X  70 392 

493.  Section  of  pulp  undergoing  fibroid  degeneration,  X  HO 392 

494-498.  Calcification  of  dental  pulp 393,  394 

499,  500.  Osteodentin 395 

501.  Bone-tissue  in  place  of  resorbed  dehtin 396 

502-505.  Suppuration  of  dental  pulp 408^11 

606.  Incisor  with  enlarged  pulp-chamber  414 

507.  Pulpitis,  X  300 414 

508.  Fibrous  degeneration  of  pulp,  X  50 415 

509.  Metallic  caps  for  capping  teeth 418 

510.  511.  Sections  showing  formation  of  secondary  dentin  in  coronal  portion  of  pulp- 

chamber,  X  100 422 

512.  Section  of  pulp  treated  with  arsenic 425 

513.  Barbed  nerve-broaches 430 

514-525.  Longitudinal  sections  of  teeth 432 

526.  Peculiarities  in  cuspids  and  bicuspids . . . .' 433 

527-534.  Sections  of  bicuspids,  showing  pulp-chamber  and  canals 433 

535-550.  Sections  of  first,  second,  and  third  molars 434 

551-557.  Abnormalities  of  dental  roots  and  canals 435 

558,  559.  Donaldson  bristles  ;  Gates-Glidden  drills 435 

560.  Donaldson  pulp-cleansers 435 

561,  562.  Nerve-extractors 436 

563.  Pulp-canal  pluggers 439 

564.  Canal  probe  guage 439 

565.  Syringe  electrode 456 

566.  Bleaching  electrode 457 

567.  Duplex  syringe 457 

568.  Nipple-expander 458 

569.  Bleaching  electrode  in  position 458 

570.  Rubber  band  causing  cementitis 460 

571.  Dental  artery  supplying  pulp  and  pericementum , 462 


XX  LIST   OF   ILLUSTRATIONS. 

FIG.  PAGE 

572.  Dunn  capillary  or  drop  syringe 463 

573.  Metal  cap  to  prevent  occlusion 464 

574.  Shreddy  sac  of  tooth  abscess 476 

575.  576.*  Spear-pointed  drills  ;  trephines 484 

577.  Puncturing  alveolar  abscess 484 

578.  Rollin  circular  knives 498 

579.  580.  Younger  trephines  and  reamers 499 

581.  Eollin  spiral  knives 499 

582.  Ottolengui  combined  drill  and  reamer 499 

583.  584.  Torsion  forceps;  bullet  forceps 503 

585.  Gooch's  double  canula  snare 503 

586-596.  Macroscopic  appearances  of  permanent  teeth  the  roots  of  which  are  being 

resorbed 510 

597,  598.  Osteoclasts,  producing  resorption  of  dental  roots 511 

599,  600.  Transverse  sections  of  roots  of  teeth,  near  apex,  X  175 514 

601-603.  Macroscopic  appearances  of  hypercementosed  teeth 514 

604,  605.  Sections  of  molar  roots,  hypercementosis,  magnified 514 

606.  Transverse  section  of  molar  roots,  near  apex,  X  75 515 

607.  Transverse  section  of  root  of  hypercementosed  tooth,  X  75 515 

608.  Transverse  section  of  alveolus  and  apex  of  root  of  abscessed  molar,  X  96 515 

609.  Inostosis,  with  formation  of  a  pearl-like  globule  resembling  enamel 515 

610.  Inostosis,  section  of  root  of  tooth,  X  80 515 

611-614.  Necrosis  of  teeth,  macroscopic  appearances 520 

615.  Epithelial  scales  and  salivary  corpuscles  from  sordes  of  mouth,  X  50 520 

616-619.  Salivary  calculus 526 

620.  Glands  of  Serres,  X  50 526 

621.  Small  scalers 518 

622.  Small  rubber  disks,  wheels,  and  cups 528 

623.  Small  revolving  brushes 528 

624.  Inflamed  peridental  membrane  from  a  cage  of  pyorrhoea  alveolaris,  X  50 544 

625.  Removing  subgingival  salivary  deposits 546 

626-628.  Pyorrhoea  alveolaris  instruments 547,  548 

629.  Medicinal  drop  syringe 548 

630-632.  Splints  for  supporting  loosened  teeth 549 

633-636.  Gouty  pericementitis  before  and  after  treatment 563 

637.  Underlying  condition  in  pyorrhoea  alveolaris 564 

638.  Fibroid  degeneration  of  pulp  in  pyorrhoea  alveolaris,  X  HO 572 

639.  Pulp  in  situ  showing  calcic  degeneration,  X  65 572 

640.  Hyaline  degeneration  of  the  pulp,  X  100 573 

641.  Colloid  degeneration  of  the  pulp,  X  21.25 573 

642.  Allport's  bur 576 

643.  Improved  dento-electric  cautery 577 

644.  Spray  apparatus — hand  instrument 578 

645.  Spray  apparatus — foot  instrument 579 

646.  Glass  tube  with  capillary  point 581 

647.  648.  Nitrous  oxide  apparatus 587 

649-651.  Gas-inhalers 588 

652,  653.  Hewitt's    apparatus    for    the    administration  of    oxygen    with    nitrous 

oxide , 589,  590 

654,  655.  Mouth-props 592 

656.  Towel  folded  as  a  cone 592 

657,  658.  Lente's  and  AUis's  inhalers 593 

659.  Aseptible  ether  inhaler 594 

660.  Mouth-mirror 600 

661.  Gum-lancet 600 

662.  Curved  scissors 600 


LIST   OF   ILLUSTRATIONS.  XXl 

F'IG.  PAGE 

663-665.  Mouth-props  and  gags 601 

666.  Laryngeal  forceps 601 

667.  Turnkey 602 

668.  Aseptic  forceps 602 

669.  Root-elevators 603 

670.  Dental  screw 608 

671.  672.  Relation  of  teeth  to  alveolar  processes 604 

673,  674.  Superior  incisor  forceps 604 

675-678.  Inferior  incisor  forceps 605,  606 

679-681.  Superior  cuspid  and  bicuspid  forceps 606,  607 

682-685.  Inferior  cuspid  and  bicuspid  forceps 607,  608 

686,  687.  Superior  first  and  second  molar  forceps  609 

688-694.  Inferior  first  and  second  molar  forceps 609-611 

695-697.  Superior  third  molar  forceps 611,  612 

698,  699.  Inferior  third  molar  forceps 612,  613 

700,  701.  Screw-forceps 613 

702-705.  Superior  root  forceps 614 

706,  707.  Inferior  root  forceps 615 

708.  Superior  alveolar  root  forceps 615 

709.  Deciduous  inferior  universal  forceps 616 

710.  Inferior  alveolar  root  forceps 616 

711.  Deciduous  superior  anterior  and  root  forceps 616 

712.  Deciduous  superior  molar  forceps 616 

713.  Deciduous  inferior  anterior  and  molar  forceps 617 

714.  Deciduous  and  superior  universal  root  forceps 617 

715.  716.  Common  deformities  of  teeth 617 

717-721.  Common  malpositions  of  teeth 617 

722.  Skiagraph  showing  misplaced  superior  cuspid 617 

723.  Misplaced  inferior  second  and  third  molars 618 

.  724,  725.  Forceps  for  extracting  misplaced  molars 618 


PRINCIPLES  AND   PRACTICE 


OPERATIVE    DENTISTRY. 


CHAPTER    I. 

CLASSIFICATION   AND   DESCEIPTIVE   ANATOMY   OF   THE   TEETH. 

S'eaely  all  of  the  mammalia  possess  a  more  or  less  complicated  dental 
system.  These  organs  are  applied  to  various  purposes,  mainly,  however, 
to  that  of  procuring  food  by  seizing  and  killing  living  prey,  or  gathering 
and  biting  off  portions  of  vegetable  material,  and  more  indirectly  in  tearing 
or  cutting  through  the  hard  protective  coverings  of  food  substances,  such 
as  the  husks  and  shells  of  nuts,  or  in  grinding,  crushing,  or  otherwise 
mechanically  dividing  the  solid  materials  before  swallowing,  so  as  to 
prepare  them  for  digestion  in  the  stomach.  Fig.  1  shows  the  peculiar 
form  of  the  teeth  of  the  mole. 

In  many  animals  certain  teeth  are  excessively  developed,  and  are  used 
as  weapons  of  offence  and  defence ;  in  others  the  presence  or  excessive 
development  of  certain  teeth  mark  the  male  sex. 

Man  is  an  omnivorous  animal  (the  term  omnivorous  comes  from  the 
Latin  omnis,  all,  and  voro,  I  eat),  and,  as  the  term  imiDlies,  eats  all  kinds 
of  food.  He  has  been  endowed  by  nature  with  organs  of  mastication 
suited  to  the  requirements  of  cutting,  tearing,  and  grinding  these  various 
forms  of  food.  Man's  teeth,  therefore,  represent  in  jDart  those  of  the 
carnivora,  or  flesh-eating  animals,  and  those  of  the  herhivora,  or  vegetable- 
eating  animals  ;  in  other  words,  certain  of  his  dental  organs  are  represent- 
ative of  both  of  these  types  of  animals.  The  incisors  and  molars  are 
typical  of  the  herbivora,  and  are  suited  to  cutting  and  grinding  vegetable 
fibre  and  grains,  while  the  cuspids  and  bicuspids  represent  the  teeth  of 
the  carnivora,  and  are  adapted  to  seizing,  tearing,  and  cutting  animal 
food. 

NUMBER   AND   CLASSIFICATION   OF   THE   TEETH. 

Man,  like  many  others  of  the  mammalia,  is  endowed  with  two  distinct 
sets  of  dental  organs,  one  designed  to  serve  the  purposes  of  the  economy 
during  infancy  and  early  childhood,  the  deciduous,  temporary,  or  milk 
teeth  ;  and  the  other  a  larger,  stronger,  and  more  numerous  set,  which  re- 
places the  deciduous  teeth,  and  is  designed  to  serve  the  purx^oses  of  the 
economy  from  childhood  to  old  age  ;  these  are  designated  as  the  permanent 
teeth. 

1 


OPERATIVE    DENTISTRY. 


The  deciduous  teeth  are  twenty  in  number,  ten  in  each  jaw,  and  are 
expressed  by  scientists  in  the  following  formula  : 

9  9  11  99 

I.  -  -    C.  ^^  -    ]\I.  ^  ^  =  20. 
22  11  2  2 

The  formula  is  read  as  follows,  beginning  at  the  median  line  :  incisors? 
two  above,  two  below  ;  cuspids,  one  above,  one  below  ;  molars,  two  above, 
two  below,  which  equals  ten  on  either  side  of  the  median  line,  or  twenty 
in  all. 

Fig.  2. 


1  ^    2  '«    3  M      II  4 
Deciduous  teeth  of  the  left  side.     (Gray.)    1  and  2,  incisors  ;  3,  euspidati ;  4  and  5,  molars. 

The  permanent  teeth  of  man  are  thirty-two  in  number,  sixteen  in  each 
jaw,  the  formula  for  which  is  written  thus  : 

I.   ??    C.  ii    B.  ~?  M.  --  =  32. 


Permanent  teeth  of  the  right  side.     (Gray.)    1,  third  molars  ;  2,  second  molars ;  3,  first  molars ;  4,  second 
bicuspidati ;  5,  first  hicuspidati ;  6,  euspidati ;  7,  lateral  incisors  ;  8,  central  incisor;. 

Beginning  at  the  median  line,  it  reads  as  follows  :  incisors,  two  above, 
two  below ;   cuspids,  one  above,   one  below  ;   bicuspids,  two  above,  two 


y  )V:     ":\^^i^M?^ 


Fig.  1. — Vertical  section  of  inferior  maxilla  and  teeth  in  silu  of  mole.    X  15. 


Fig.  4.— Showing  structures  of  a  tooth. 
1,  enamel ;  2,  cementum  ;  3,  dentin  ;  4,  pulp- 
chamher. 


Fig.  5. — Occlusion  of  the  teeth.     (After  Cryer.) 


Root 


Apex 


Cervix 


Crown 


Cutting  edge 
Fig.  6. — Superior  left  central  incisor,  labial  surface. 
(Enlarged.) 


Fig.  7. — Superior  right  central  incisor,  labial  surface, 
showing  short  root.    ( Enlarged. ) 


CLASSIFICATION    AND    DESCRIPTIVE    ANATOMY   OF    THE    TEETH.  3 

below ;  molars,  three  above,  three  below,  equals  sixteen  on  either  side  of 
the  median  line,  or  thirty-two  in  all. 

The  ten  anterior  permanent  teeth  of  each  jaw  are  sometimes  called  the 
teeth  of  replacement,  or  succedaneous  teeth,  from  the  fact  that  they  replace 
the  deciduous  teeth.  The  permanent  incisors  and  cuspids  take  the  x)lace 
of  the  temporary  teeth  of  the  same  name,  while  the  bicuspids  assume  the 
positions  occupied  by  the  temporary  molars.  The  permanent  molars 
appear  one  by  one  behind  the  position  occupied  by  the  second  deciduous 
molars. 

DESCRIPTIVE   ANATOMY   OF   THE   TEETH. 

The  teeth  are  specialized  organs  of  mastication  implanted  within  the 
alveolar  processes  of  the  superior  and  inferior  maxillse  in  man  and  in  many 
animals.  The  teeth  are  composed  of  five  tissues  (Fig.  4)  :  a  vitreous-like 
substance  which  completely  covers  the  crown — the  enamel  (1) ;  a  bone-like 
substance  which  envelops  the  root — the  cementum  (2)  ;  and  a  hard  substance, 
less  dense  than  enamel  but  harder  than  bone,  which  forms  the  interior  or 
body  of  the  organ — the  dentin  (3)  ;  while  a  small  mass  of  soft  tissue  occu- 
pies a  central  cavity  (4)  within  the  crown  and  the  root — the  pulj) ;  and  a 
fibrous  membrane  covers  the  cementum  of  the  root — the  pericementum. 

In  a  normally  developed  individual  of  the  genus  homo  the  teeth  are 
arranged  in  the  form  of  two  parabolic  or  elliptical  curves,  the  su^oerior 
arch  describing  a  trifle  larger  curve  than  the  inferior,  so  that  the  teeth  of 
the  former  slightly  overreach  their  antagonists  in  the  latter.  The  buccal 
cusps  of  the  ux^iDer  bicuspids  and  molars  close  over  the  buccal  cusps  of  the 
lower  teeth ;  this  brings  the  buccal  cusps  of  the  lower  teeth  within  the 
sulci  of  the  upper,  and  the  palatal  cusj)S  of  the  upper  teeth  within  the 
sulci  of  the  lower.  The  incisors,  cuspids,  and  bicuspids  of  the  lower  jaw 
are  smaller  than  the  corresponding  teeth  in  the  upper,  the  greatest  differ- 
ence being  in  the  size  of  the  incisors.  The  superior  incisors  and  cuspids 
are  slightly  longer  than  the  inferior  and  overlaj)  them,  while  the  cuspids 
and  molars  not  only  overreach  their  opposites  in  the  inferior  maxilla,  but 
so  interlock  at  their  occlusal  surfaces  that  each  tooth,  except  the  third 
sux^erior  molars,  occludes  or  antagonizes  with  two  of  its  fellows  in  the 
opposite  jaw,  when  the  teeth  are  brought  into  their  normal  occlusion.  (Fig. 
5. )  This  arrangement  permits  the  whole  of  the  occlusal  surfaces  of  these 
teeth  to  be  brought  into  contact  by  the  various  movements  of  the  jaws  in 
mastication,  thus  rendering  the  function  of  triturating  the  food  and  pre- 
paring it  for  digestion  most  effective. 

A  normal  incisor  tooth  presents  certain  characteristics  which  are  com- 
mon to  all  the  dental  organs  of  man  ;  it  will  therefore  serve  the  purpose  of 
illustrating  the  anatomical  divisions  of  the  teeth,  which  are  as  follows  :  the 
crown,  the  cervix,  the  root,  the  pidp-chaml>er,  the  pulp-canal,  the  morsal-'<^  or 
cutting  edge,  the  apex,  and  the  apical  foramen.  A  more  minute  description 
relative  to  the  cusps,  surfaces,  angles,  margins,  grooves,  fissures,  etc.,  will 
be  reserved  for  the  special  anatomy  of  the  individual  teeth. 

*  The  term  morsal  is  used,  following  the  suggestion  of  Dr.  Thompson,  in  the- place 
of  incisive  or  cutting  edge  and  occlusal  surface. 


4  OPERATIVE   DENTISTRY. 

The  crown  is  tliat  portion  of  the  tooth  which  is  visible  within  the 
mouth,  projecting  beyond  the  gum  ;  the  cervix  or  necJc  is  that  part  repre- 
sented by  a  constriction  between  the  crown  and  the  root  at  the  point  where 
the  enamel  and  the  cementum  meet,  or,  in  other  words,  the  portion  grasped 
by  the  margin  of  the  gum  ;  the  root  is  that  part  which  is  implanted  within 
the  alveolar  process  of  the  jaw  and  covered  by  the  gum  ;  the  morsal  edge  or 
cutting  edge  is  that  portion  of  the  crown  which  occludes  or  antagonizes 
with  a  tooth  in  the  opposite  jaw  ;  the  apex  is  the  terminal  end  of  the  root, 
that  portion  farthest  removed  from  the  crown  (Fig.  6 )  ;  the  pulp -chamber 
is  a  cavity  or  cul-de-sac  located  within  the  crown,  and  may  be  termed  a 
coronal  enlargement  of  the  pulp-canal  which  extends  through  the  centre 
of  the  root  from  its  apex  to  the  pulp-chamber  within  the  crown  ;  the  apical 
foramen  is  the  orifice  or  entrance  to  the  pulp-canal  located  in  the  apex  of 
the  root. 

ARCHITECTURAL   DESIGN   OF   THE   TEETH. 

It  is  important  to  the  dental  student  that  he  understand  and  appreciate 
the  architectural  design  upon  which  nature  has  constructed  the  dental 
organs.  The  more  closely  he  studies  this  design,  in  both  their  gross  and 
minute  anatomy,  the  more  will  he  become  impressed  with  the  x)erfection 
of  the  general  plan  and  the  admirable  adaptation  of  their  form,  their 
structure,  and  their  tissues  to  perform  the  functions  for  which  they  were 
created. 

The  form  of  the  teeth  is  designed  upon  the  plan  of  the  cone,  modified 
to  meet  the  individual  requirements  of  the  several  classes  of  teeth  ;  some 
are  comxDosed  of  a  simj^le  cone,  like  the  incisors  and  cusi3ids,  while  others 
are  a  combination  of  two  or  more  cones,  as  in  the  bicuspids  and  molars. 
In  no  way  can  these  facts  be  taught  so  well  as  by  modelling  in  clay  the 
forms  of  the  various  classes  of  teeth,  commencing  with  the  sim^^le  forms 
as  expressed  in  the  single-rooted  teeth,  and  progressing  to  the  more  com- 
plex through  a  series  of  double  and  multiple  cones  in  the  formation  of  the 
bicuspids  and  molars. 

THE   INCISORS. 

There  are  eight  incisor  teeth  in  the  dental  series  of  man,  four  in  the 
upper  jaw  and  four  in  the  lower,  two  situated  upon  either  side  of  the 
median  line  of  the  jaw  ;  the  first  are  termed  the  central  incisors,  and  those 
next  in  order  upon  the  distal  side  of  the  centrals  are  known  as  the  lateral 
incisors. 

The  situation  of  the  central  incisors  in  the  extreme  anterior  portion  of 
the  jaw  upon  opposite  sides  of  the  median  line  causes  their  mesial  sur- 
faces to  approximate  each  other. 

The  function  of  the  incisor  tooth  is  to  cut  or  incise  the  food, — ^hence  its 
name,  which  is  derived  from  the  Latin,  incido,  to  cut. 

These  teeth  are  all  designed  upon  the  form  of  the  truncated  cone,  with 
slight  modifications,  to  meet  the  requirements  of  the  individual  organ. 

The  Superior  Central  Incisor. — This  tooth  is  in  form  a  modified 
truncated  cone  with  its  base  flattened  out  to  form  the  morsal  or  cutting 
edge.    It  presents  for  examination  four  surfaces, — labial,  lingual,  mesial,  and 


CLASSIFICATION   AND   DESCRIPTIVE   ANATOMY   OF   THE   TEETH.  5 

distal^-  two  angles, — mesial  and  distal;  and  a  morsal  edge.  The  general 
fornf  of  the  crown  is  that  of  the  wedge  or  chisel,  the  edge  being  quite 
thin,  the  angles  rounded,  and  the  thickness  rapidly  increasing  to  the  cer- 
vix of  the  tooth.  It  is  also  slightly  curved  from  the  cervix  to  the  morsal 
edge,  and  curved  over  mesio-distally,  so  that  the  labial  surface  is  somewhat 
convex  and  the  palatal  concave. 

The  labial  surface  (Fig.  7)  of  the  crown  is  in  general  outline  an  imper- 
fect quadrilateral,  the  cervical  margin  being  rounded.  This  surface  has 
four  margins, — mesial,  distal,  cervical,  and  morsal  or  incisive.     (Fig.  8.) 

The  mesial  margin  begins  at  the  morsal  margin  or  cutting  edge,  and 
extending  upward,  usually  with  a  slight  distal  inclination,  unites  with 
the  cervical  margin.  The  distal  margin  also  begins  at  the  morsal  mar- 
gin, and  extends  uj)ward  with  a  slight  mesial  inclination,  uniting  with 
the  cervical  margin.  Both  of  these  margins  are  more  or  less  convex. 
The  cervical  margin  is  somewhat  rounded,  the  form  following  the  outline 
of  the  gingival  border,  where  it  unites  with  the  mesial  and  distal  mar- 
gins. The  morsal  margin  extends  from  the  mesial  margin  to  the  distal 
margin. 

The  union  of  the  mesial  and  morsal  margins  form  the  mesial  angle, 
while  the  union  of  the  distal  and  morsal  margins  form  the  distal  angle. 
The  mesial  angle  is  usually  pointed  and  square,  while  the  distal  is  much 
more  obtuse.  Two  shallow  grooves  or  depressions— the  lahial  grooves — 
traverse  the  labial  surface  in  a  longitudinal  direction,  dividing  it  into 
three  lobes,  the  mesial,  median,  and  distal.  These  grooves  extend  from  the 
morsal  edge  to  the  middle  or  upper  third  of  the  labial  surface,  where  they 
broaden  out  and  disappear.  They  are  termed  developmental  lines  (Black), 
and  represent  the  three  x)rimitive  j^lates  of  calcification  in  the  develop- 
ment of  the  tooth,  the  grooves  being  formed  by  the  union  of  these  plates 
with  each  other.  Occasionally  one  or  more  transverse  ridges  are  found 
upon  the  cervical  portion. 

The  lingual  surface  (Fig.  9)  of  the  crown  is  triangular  in  outline,  smaller 
than  the  labial  surface,  and  presenting  a  more  or  less  angular  concavity, 
the  lingual  fossa.  This  fossa  is  bounded  by  three  marginal  ridges  and  the 
morsal  or  cutting  edge. 

The  mesio-marginal  ridge  extends  from  the  mesial  angle  upward  to  the 
cervico-marginal  ridge,  following  the  curvature  of  the  mesial  margin. 

The  disto -marginal  ridge  extends  from  the  distal  angle  to  the  cervico- 
marginal  ridge,  following  the  curvature  of  the  distal  surface. 

The  cervico-marginal  ridge  forms  a  curved  line  at  the  cervix  or  base  of 
the  crown,  uniting  by  its  extremities  with  the  mesial  and  distal  marginal 
ridges.  The  marginal  ridges  are  often  high  and  conspicuous,  and  the 
cervico-marginal  ridge  is  sometimes  develo^Ded  into  a  cusp,  the  ridge  at 
the  base  forming  a  girdle  or  cingulum.  The  lingual  fossa  is  usually 
smooth,  but  occasionally  it  forms  a  deep  depression  or  pit,  while  a  fissure 
may  extend  from  it  into  the  cervico-marginal  ridge.  Two  longitudinal 
grooves  are  sometimes  seen  traversing  the  lingual  fossa,  which  correspond 
to  the  developmental  grooves  upon  the  labial  surface. 

The  Mesial  and  Distal  Surfaces. — The  outlines  of  these  surfaces  (Figs, 


6  OPERATIVE    DENTISTRY. 

10  and  11)  are  irregular  triangles,  with  tlie  base  directed  towards  the  root 
and  the  apex  terminating  at  the  incisive  or  morsal  edge.  The  base  of  the 
triangle  is  concaved  at  the  cervical  margin,  and  the  apex  rounded  or  con- 
vex at  the  morsal  edge. 

These  surfaces  have  three  margins, — labial,  lingual,  and  cervical.  The 
mesial  surface  is  slightly  longer  than  the  distal  surface,  and  presents  a 
more  or  less  convex  and  rounded  form,  slightly  flattened  near  the  cervical 
margin. 

The  distal  surface  is  rounded  as  in  the  mesial,  but  more  curved  in  its 
longitudinal  axis.  The  labial  margins  of  these  surfaces  are  convex, 
following  the  outline  of  the  labial  surface,  while  the  lingual  and  cervical 
margins  present  concave  outlines,  following  the  curves  of  the  lingual 
surface,  and  the  cervical  line. 

The  incisive  edge  or  morsal  vnargin  of  the  crown  is  formed  by  union  of 
the  labial  and  lingual  surfaces,  and  extends  in  a  nearly  straight  line 
from  the  mesial  to  the  distal  surface,  with  a  slight  downward  j)itch 
towards  the  median  line.  In  a  recently  erupted  tooth  this  line  is  often 
broken  by  the  presence  of  the  developmental  grooves ;  these,  however, 
soon  disappear  with  use,  leaving  the  line  comparatively  straight.  In  a 
normal  occlusion  these  teeth  shut  over  the  lower  incisors,  but  occasion- 
ally they  will  be  found  to  occlude  squarely  with  their  fellows  of  the  lower 
jaw. 

The  cervix  or  cervical  line  or  margin  is  clearly  and  distinctly  marked  by 
the  free  extremity  of  the  enamel  which  covers  the  crown  of  the  teeth.  The 
termination  of  the  enamel  at  the  neck  of  the  tooth  marks  the  extent  of  the 
peridental  membrane.  The  enamel  edge,  which  slopes  off  more  or  less 
abruptly  to  meet  the  cementum,  does  not  form  a  straight  line  around  the 
tooth,  but  curves  upward  upon  the  root  at  the  labial  and  lingual  surfaces 
and  downward  at  the  mesial  and  distal  surfaces,  thus  forming  in  outline  a 
double  convexity  and  a  double  concavity. 

The  root  in  section  of  the  tooth  at  the  cervix  shows  it  to  be  broader 
on  the  labial  than  the  lingual  surface, — i)ear-shaped, — and  this  condition 
is  maintained  throughout  the  greater  length  of  the  root. 

In  general  outline  the  root  has  the  form  of  a  slender  cone.  The  aver- 
age length  of  the  superior  central  incisor  is  0.88  inch  (2.23  centimetres), 
of  the  crown  0.39  inch  (0.99  centimetre),  and  of  the  root  0.49  inch  (1.24 
centimetres).* 

The  pulp-chamber  is  large,  and  the  pulp-canal  usually  gives  free  access 
to  the  aioex.  In  young  teeth  the  cornua  extend  well  towards  the  angles, 
while  in  old  x>ersons  the  pulp-chamber  and  canal  is  often  constricted, 
making  it  difficult  of  access. 

The  Superior  Lateral  Incisor. — This  tooth  is  the  second  in  the 
dental  arch  from  the  median  line,  and  approximates  the  central  incisor 
upon  its  distal  surface.  It  is  a  little  shorter,  and  about  a  third  narrower 
than  the  central  incisor,  has  the  same  general  form  and  architectural 
design,  and  is  possessed  of  the  same  developmental  grooves. 

*  AU  measurements  of  the  teeth  are  taken  from  Black's  Dental  Anatomy. 


Mesial 
angle 


Morsal  edge  Labial  grooves 

Fig.  8. — Superior  left  central  incisor,  labial  surface. 
(Enlarged.) 


Cervical 

margin 

Cervico- 

marginal 

ridge 

Distal 
margin 

Distal 
angle 

Disto- 

marginal 

ridge 

Lingual  fossa 
Fig.  9. — Superior  left  central  incisor,  lingual  surface. 
(Enlarged.) 


Pig.  10.- 


-Superior  left  central  incisor,  mesial  surface. 
(Enlarged.) 


Fig.  11. — Sviperior  left  central  incisor,  distal  surface. 
(Enlarged.) 


Labial  grooves 

Fig.  12. — Superior  right  lateral  incisor,  labial  surface. 

(Enlarged.) 


Morsal  edge 
Fig.  l.S. — Superior  right  lateral  incisor,  lingual  surface. 
(Enlarged.) 


Fig.  15. — Superior  right  lateral  incisor,  mesial  surface.        Fig.  16.— Superior  right  lateral  incisor,  distal  surface. 
(Enlarged.)  (Enlarged.) 


CLASSIFICATION   AND   DESCRIPTIVE   ANATOMY   OF   THE   TEETH.  7 

The  crown  presents  for  examination  four  surfaces,  labial^  Ungual,  mesial, 
and  distal  ^-  a  cervical  margin,  an  incisive  or  morsal  edge,  a  mesial  and  a  distal 
angle. 

The  labial  surface  of  the  crown  (Fig.  12)  is  more  rounded  than  in  the 
central,  the  mesial  angle  is  acute,  and  the  morsal  edge  sloi)es  upward  to  a 
rounded  and  obtuse  distal  angle.  The  mesial  half  of  the  crown  seems  to 
partake  of  the  form  of  the  central  incisor,  while  the  distal  half  approaches 
the  form  of  the  cuspid.  In  the  young  tooth  the  morsal  edge,  as  in  the  cen- 
tral, presents  three  tubercles,  more  or  less  distinct,  with  the  developmental 
grooves  passing  between  them. 

The  lingual  surface  (Fig.  13)  in  a  majority  of  instances  is  the  broadest 
part  of  the  crown.  It  is  less  concave  than  in  the  central,  but  more  de- 
pressed at  the  base  of  the  cervical  ridge.  The  mesial  and  distal  marginal 
ridges  are  in  proportion  to  the  size  of  the  tooth,  broader  and  stronger 
than  in  the  centrals.  The  cervical  ridge  is  also  well  marked  and  propor- 
tionately broader  and  stronger  than  in  the  central. 

Occasionally,  however,  the  marginal  ridges  are  but  slightly  developed  ; 
the  surface  is  then  quite  smooth.  The  lingual  fossa  may  be  divided  by  a 
longitudinal  ridge  with  slight  depressions  upon  either  side  between  it  and 
the  marginal  ridges.  The  cervical  ridge  is  sometimes  very  prominent, 
forming  a  cingulum,  at  the  centre  of  which  a  tubercle  is  often  developed. 
An  exaggerated  development  of  this  cusp  or  cingule 
is  shown  in  Fig.  14,  a,  from  a  case  reported  by  W.  H.  ^*^ 

Mitchell. 

As  a  consequence  of  this  greater  prominence  of  the 
cingulum,  and  the  marked  depression  or  pit  so  often 
found  at  its  base,  caries  is  more  liable  to  occur  upon 
the  lingual  surfaces  of  the  superior  laterals  than  upon 
those  of  the  central  incisors. 

The  mesial  and  distal  surfaces  (Figs.  15  and  16) 
present  a  triangular  or  Y-shaped  outline  similar  to  that 
of  the  central  incisor.  The  mesial  surface  is  rounded  near  the  morsal 
edge,  but  considerably  flattened  near  the  cervix.  A  slight  depression 
sometimes  exists  at  this  point,  while  the  mesio-labial  angle  occasionally 
presents  a  flattened  or  depressed  jDoinfc  midway  between  the  morsal  edge 
and  the  cervix.  The  distal  surface  is  convex  in  all  directions,  and  quite 
full  at  the  morsal  or  incisive  third  5  from  this  point  it  slopes  towards 
the  cervical  line,  where  it  becomes  quite  flat. 

The  morsal  edge  is  divided  into  two  parts  by  a  more  or  less  prominent 
tubercle.  The  mesial  half  is  straight,  like  that  of  the  central,  while  the 
distal  half  has  a  slight  upward  slope,  terminating  in  a  rounded  distal 
angle.  When  the  tubercle  becomes  worn  off,  the  edge  is  straight,  with  a 
pitch  towards  the  median  line. 

The  cervix  is  considerably  flattened  mesio-distally.  Section  of  the  root 
at  this  point  shows  the  form  to  be  a  flattened  oval.  The  cervical  line 
follows  the  same  course  as  in  the  central  incisor,  having  an  upward  curve 
upon  the  labial  and  lingual  surfaces,  and  a  downward  curve  ujDon  the 
mesial  and  distal  surfaces. 


8  OPERATIVE    DENTISTRY. 

The  enamel  margin  does  not,  as  a  rule,  end  so  abruptly  as  in  tlie  central 
incisors,  although  occasionally  it  will  end  in  a  sharply  defined  ridge. 

The  root  of  the  tooth  is  conical,  but  more  or  less  flattened  mesio- 
distally  ;  its  labio-lingual  diameter  at  the  neck  is  about  one-third  greater 
than  its  mesio-distal  diameter.  The  root  is  generally  straight,  but  in  many 
specimens  the  apex  has  a  slight  distal  curvature.  Occasionally  it  is  very 
crooked.  The  average  length  of  the  superior  lateral  incisor  is  0.85  inch 
(2.15  centimetres),  of  the  crown  0.34  inch  (0,86  centimetre),  and  of  the 
root  0.51  inch  (1.29  centimetres). 

Tlie  lateral  incisors  are  the  most  variable  in  size  and  form  of  all  the 
dental  series  of  man,  and  they  more  frequently  fail  to  appear  in  the  dental 
arch — suppressed— than  any  others  except  the  third  molars.  They  are  often 
imperfectly  developed,  and  not  infrequently  present  a  conical  or  peg- 
shaped  form.  In  one  instance  which  has  come  under  the  observation  of 
the  writer,  the  superior  lateral  incisors  have  been  absent  in  certain  mem- 
bers of  a  family  for  three  generations.  The  father  had  never  erupted 
these  teeth,  his  only  daughter  had  the  same  deformity,  and  of  her  four 
children,  two  boys  and  two  girls,  the  eldest  son  and  both  daughters  have 
never  erupted  them,  while  these  teeth  in  the  second  son  are  developed  and 
peg-shaped. 

The  pulp-canal  partakes  of  the  shape  of  the  root,  which  is  generally 
flattened,  and  when  the  root  is  straight  it  can  be  readily  entered  and  fol- 
lowed to  the  apex  5  but  in  operating  for  the  removal  of  the  pulp,  the 
possibility  of  encountering  a  root  with  a  curved  apical  end  must  not  be 
overlooked. 

THE   LOWER   INCISORS. 

The  lower  incisors  have  the  general  outlines  of  the  superior  laterals,  but 
they  are  in  every  way  smaller,  the  roots  are  much  more  flattened  mesio- 
distally,  and  often  have  a  groove  upon  the  mesial  and  distal  surfaces  run- 
ning from  the  cervix  to  the  apex. 

The  labio-lingual  diameter  of  the  root  is  much  greater  than  its  mesio- 
distal  diameter.  They  are  located  in  the  anterior  portion  of  the  lower  jaw 
upon  either  side  of  the  median  line,  opposite  the  superior  incisors,  with 
which  they  occlude  in  cutting  food.  The  developmental  lines  are  the 
same,  but  the  tubercles  upon  the  morsal  edge  and  the  labial  grooves  are 
less  strongly  marked  than  in  the  superior  incisors. 

The  lower  central  incisor  is  the  smallest  tooth  of  the  dental  series  of 
man.  It  is  chisel-shaped  in  form.  The  crown,  viewed  mesio-distally  and 
labio-lingually,  is  composed  of  a  double  wedge.  The  widest  portion  of  the 
crown  is  the  morsal  edge,  which  is  thin  and  straight.  From  this  point  it 
slopes  slightly  to  the  cervix,  where  it  is  only  about  one-half  as  wide  as  at 
the  edge. 

The  labial  surface  (Fig.  17)  has  the  outline  of  a  slender  wedge,  its  widest 
portion  at  the  morsal  edge,  and  its  narrowest  at  the  cervix.  It  is  nearly 
straight,  or  only  slightly  convex  near  the  edge,  but  as  it  approaches  the 
cervix  it  becomes  more  rounded  and  convex.  The  cervical  margin  is  well 
defined  and  concave  towards  the  root.     The  mesio-labial  and  disto-labial 


Ijrtbial  groOA't'S 


Mesial 
angle 

Mesio- 
marginal 
ridge 
Cervical 

ridge  Cervical 

line 


Fig.  17. — Inferior  right  central  incisor,  labial  surface.        Fig.  18. — Inferior  right  central  incisor,  lingual  surface. 
( En  larged . )  ( Enlarged . ) 


Fig.  19.— Inferior  right  central  incisor,  mesial  surface.       Fig.  20.— Inferior  right  central  incisor,  distal  surface. 
(Enlarged.)  _  (Enlarged.) 


Fig.  21. — Inferior  right  lateral  incisor,  labial  surface.        Fig.  22. — Inferior  right  lateral  incisor,  lingual  surface. 
(Enlarged.)  (Enlarged.) 


Fig.  23. — Inferior  right  lateral  incisor,  mesial  surface.       Fig.  24. — Inferior  right  lateral  incisor,  distal  surface. 
(Enlarged.)  (Enlarged.) 


CLASSIFICATION    AND    DESCRIPTIVE    ANATOMY    OF    THE    TEETH.  9 

margins  are  rounded  off  at  tlie  expense  of  tlie  labial  surface.  The  mesial 
angle  is  quite  acute,  and  tlie  distal  angle  slightly  obtuse  and  rounded. 

The  lingual  surface  (Fig.  18)  is  concave  from  the  mesial  edge  to  the  cervix, 
but  is  nearly  flat,  or  only  slightly  concave  mesio-distally.  The  marginal 
ridges  are  not  strongly  marked. 

The  mesial  and  distal  surfaces  (Figs.  19  and  20)  are  Y-shaped  in  outline, 
with  the  apex  directed  towards  the  morsal  edge  of  the  crown.  They  are 
convex  near  the  edge,  but  become  flattened  and  even  slightly  concave  at 
the  cervix. 

The  cervix  is  flattened  mesio-distally,  the  greatest  diameter  being  the 
labio-lingual.     Section  at  this  i)oint  gives  the  form  of  a  comi^ressed  oval. 

The  root  is  flattened  like  the  cervix,  for  its  entire  length.  The  apex 
sometimes  has  a  distal  curve.  The  groove  upon  the  mesial  and  distal 
surfaces  is  sometimes  quite  deep  and  occasionally  results  in  bifurcation. 

ThQ  ])ulp  canal  is  thin  and  flattened,  partaking  of  the  form  of  the  root ; 
in  some  instances  it  is  with  great  difficulty  that  the  canal  can  be  entered 
with  the  most  delicate  instruments.  The  average  length  of  the  inferior 
central  incisor  is  0.81  inch  (2.05  centimetres),  of  the  crown  0.34  inch  (0.86 
centimetre),  and  of  the  root  0.47  inch  (1.19  centimetres). 

The  inferior  lateral  incisor  (Figs.  21,  22,  23,  and  24)  is  similar  in 
form  to  the  inferior  central,  but,  unlike  the  superior  incisors,  it  is  distinctly 
larger  than  the  centrals,  not  only  in  width  of  crown,  but  also  in  the  length 
of  the  root,  while  the  marginal  ridges  are  more  strongly  marked  and  the 
fossa  more  distinct.  The  morsal  edge  has  a  slight  distal  pitch,  and  the 
distal  angle  is  obtuse  and  rounded. 

The  average  length  of  the  inferior  lateral  incisors  is  0.85  inch  (2.15  centi- 
metres), of  the  crown  0.35  inch  (0.88  centimetre),  and  of  the  root  0.50 
inch  (1.26  centimetres). 

THE   CUSPIDS. 

There  are  four  cuspids  in  the  dental  series  of  man,  two  in  each  jaw. 
They  are  situated  just  in  front  of  the  angle  of  the  mouth,  between  the 
lateral  incisor  and  the  first  bicuspid  tooth ;  they  are  the  third  in  order 
from  the  median  line,  and  form  the  spring  of  the  superior  dental  arch. 
These  teeth  are  variously  known  as  cuspids,  cuspidati,  canines,  and  eye- 
teeth.     The  term  cuspid  comes  from  the  Latin  cuspis,  a  i3oint. 

The  cuspid  teeth  are  in  all  respects  larger  and  stronger  than  the 
incisors,  the  crown  is  thick  and  spear-pointed,  and  the  root  long  and 
heavy. 

The  architectural  form  of  these  teeth  adapts  them  for  seizing,  piercing, 
and  tearing  animal  food,  and  they  represent  the  carnivorous  element  in 
man. 

The  Superior  Cuspids. — The  crowns  of  the  superior  cusiDids  present 
for  examination  four  surfaces,  the  labial,  lingual,  mesial,  and  distal,  two 
margins,  the  cervical  and  morsal,  and  two  angles,  the  mesial  and  the  distal. 
The  general  outline  of  the  crown  is  that  of  a  short  cone  with  its  base 
at  the  gum  line,  and  it  represents  the  primitive  conical  teeth  of  many  of 
the  fishes. 


10  OPERATIVE    DENTISTRY. 

The  lahial  surface  (Fig.  25)  of  tlie  crown  in  outline  is  spear-shaped.  It 
is  convex  in  all  directions,  and  is  much  more  rounded  mesio-distally  than 
the  incisors.  The  developmental  grooves  and  ridges  are  often  quite  promi- 
nent. The  distal  groove  is  usually  most  strongly  marked,  which  brings 
the  central  and  distal  lobes  into  greater  prominence.  This  surface  is 
bounded  by  five  margins,  the  mesial,  distal,  cervical,  mesio-morsal,  and 
disto-morsal. 

The  mesial  and  distal  margins  are  rounded  and  convex  from  the  morsal 
edge  to  the  cervical  margin ;  the  convexity  being  greatest  in  the  distal 
margin.  The  distal  margin  is  slightly  shorter  than  the  mesial  on  account 
of  the  sharper  slope  of  the  disto-morsal  edge. 

The  cervical  margin  follows  the  contour  of  the  gum*  line,  and  unites 
with  the  mesial  and  distal  margins. 

The  morsal  margin  is  divided  by  a  prominent  cusp,  from  the  summit  of 
which  gi-adually  slope  away  the  mesio-morsal  and  disto-morsal  margins. 

The  mesio-morsal  margin  slopes  slightly  ui)ward,  and  is  usually  a  trifle 
concave,  though  occasionally  it  is  convex. 

The  disto-7norsal  margin  may  be  described  in  the  same  manner,  except 
that  it  is  a  little  longer,  and  has  a  slightly  more  i)ronounced  upward  slope 
and  a  deeper  concavity.  The  widest  part  of  the  labial  surface  is  at  a  line 
drawn  from  the  mesial  to  the  distal  angles ;  the  narrowest  part  is  at  the 
cervical  margin. 

The  lingual  surface  (Fig.  26)  presents  nearly  the  same  general  outline  of 
the  labial  surface,  with  the  exceptions  that  it  is  more  flat,  sometimes  concave, 
and  has  three  generally  well-defined  marginal  ridges.  The  mesio-marginal 
and  disto-marginal  ridges  arise  at  the  mesial  and  distal  angles,  and  pass 
upward,  where  they  unite  with  the  cervico-marginal  ridge,  which  may  be 
said  to  be  formed  by  the  union  or  continuation  of  the  two  former  ridges. 
The  cervico-marginal  ridge  is  sometimes  quite  prominent,  terminating  in  a 
more  or  less  pronounced  tubercle  or  cusj).  Between  the  mesio-  and  disto- 
marginal  ridges  there  is  a  prominence  known  as  the  lingual  or  triangular 
ridge,  upon  either  side  of  which  are  sometimes  deep  fossa  or  fissures,  but 
more  frequently  they  are  shallow  and  ill-defined. 

The  mesial  surface  (Fig.  27)  resembles  that  of  the  central  incisor  in  many 
respects.  It  is  convex  in  all  directions  at  the  mesial  angle,  but  as  it  ap- 
proaches the  cervix  it  becomes  flattened  and  occasionally  concave. 

The  distal  surface  (Fig.  28)  in  general  outline  is  similar  to  the  mesial 
surface,  except  that  it  is  more  rounded,  and,  as  it  nears  the  cervix,  not 
quite  so  flat.  The  distance  from  the  cervix  to  the  distal  angle  is  nearly 
one-third  shorter  than  the  distance  on  the  mesial  surface  from  the  cervix 
to  the  mesial  angle. 

The  morsal  edge  by  its  form  gives  to  the  cuspid  tooth  a  double  function, 
that  of  incising  and  penetrating.  The  morsal  edge  combines  a  cusp  which 
is  placed  near  the  centre,  to  the  long  axis  of  the  tooth,  and  two  cutting  or 
incisive  edges  which  slope  away  from  it  in  an  upward  direction,  and  termi- 
nate at  the  mesial  and  distal  angles.  The  distal  edge  is  longer  than  the 
mesial,  and  it  has  a  more  acute  upward  slope.  The  sharp  cusp  is  soon 
worn  off,  and  in  old  age  the  morsal  edge  may  be  reduced  to  a  straight  line. 


Apex 


Disto- 
morsal 
margin 


Morsal  margin 
Pig.  25.— Superior  right  cuspid,  labial  surface. 
(Enlarged.) 


Cervical 

margin 

Cervical 
line 

Mesial 
angle 

Mesio- 
morsal 

Mesial 
angle 

margin 

Fig.  26.- 


-Superior  right  cuspid,  lingual  surface. 
(Enlarged.) 


Fig.  27.— Superior  right  cuspid,  mesial  surface. 
(Enlarged.) 


Fig.  28.— Superior  right  cuspid,  distal  surface. 
(Enlarged.) 


Distc- 
inoi'Sii  1 

Distill 
aiiKli3 

Cervical 
inargiii 

^0^H 

M 

Mcsin- 
inorsal 
edge 

Mesial 


Labial 
lidge 

Cervical 
ridge 


-Inferior  right  cuspid,  labial  surface. 
(Enlarged.) 


]^iG.  .30.— Inferior  right  cuspid,  lingual  surface. 
(Enlarged.) 


Fig.  31. — Inferior  right  cuspid,  mesial  surface. 
(Enlarged.) 


Fig. 


2. — Inferior  right  cuspid,  distal  surface. 
(P^nlarged.) 


CLASSIFICATION    AND    DESCRIPTIVE    ANATOMY    OF    THE    TEETH.  11 

The  cervix  on  section  presents  a  flattened  oval.  The  enamel  line 
maintains  about  the  same  outline  as  in  the  central  incisors,  curving 
upward  upon  the  labial  and  lingual  surfaces,  and  downward  upon  the 
mesial  and  distal.  Occasionally  it  presents  a  slight  dei)ression  both 
mesially  and  distally,  which  may  be  continued  upon  the  root  as  a  groove. 

The  root  is  the  longest  of  all  the  human  teeth,  and  is  irregularly  coni- 
cal in  form,  tapering  to  a  slender  point ;  it  is  usually  straight,  but  may  be 
curved  or  very  crooked.  In  size  it  is  about  one-third  larger  than  the 
central  incisor.  It  is  flattened  slightly  mesio-distally,  and  occasionally 
grooved. 

The  pulp-canal  is  large  and  accessible,  usually  of  the  same  form  as  the 
root,  and  except  when  the  root  is  curved  or  crooked,  can  be  easily  followed 
to  its  apex. 

The  average  length  of  the  superior  cuspid  is  1.05  inches  (2.66  centi- 
metres), the  average  length  of  the  crown  is  0.37  inch  (0.94  centimetre), 
and  of  the  root  0.68  inch  (1.72  centimetres). 

The  Inferior  Cuspids. —  There  is  probably  a  greater  similarity  be- 
tween the  superior  and  inferior  cuspids  than  between  any  other  class  of 
teeth  in  the  human  mouth.  They  are  alike  in  form  and  outline,  though 
the  inferior  are  somewhat  smaller.  The  crowns  are  a  little  longer,  and  this 
makes  them  appear  more  slender  ;  they  are  also  more  flattened  mesio-dis- 
tally at  the  cervix  and  in  the  root.  These  teeth  are  heavily  built  and 
firmly  set  in  their  alveoli,  in  order  to  enable  them  to  perform  the  double 
function  of  incising  and  tearing  food.  The  cusp  is  generally  more  promi- 
nent and  pointed  than  in  the  superior  cuspids.  The  crown  opposes  the 
mesial  surface  of  the  superior  cuspid  and  the  distal  surface  of  the  superior 
lateral  incisor. 

The  labial  surface  (Fig.  29)  of  the  crown  is  smooth  and  convex,  the  de- 
velopmental grooves  are  less  prominent  than  in  the  superior  cuspids  ;  the 
labial  ridge,  however,  is  well  developed,  and  extends  from  the  cusp  to  the 
cervical  margin,  giving  additional  strength  to  the  crown.  Transverse 
ridges  are  also  occasionally  present  in  the  cervical  region.  To  accommo- 
date the  occlusion  of  the  superior  teeth,  the  labial  surface  of  the  crown  is 
inclined  inward. 

The  lingual  surface  (Fig.  30)  is  quite  smooth,  the  ridges  and  grooves 
being  less  strongly  marked  than  in  the  superior  cuspids.  The  lingual 
ridge,  which  extends  from  the  cusp  to  the  cervical  ridge,  is,  however, 
sometimes  quite  prominent.  In  exceptional  cases  the  cervical  ridge  is 
strongly  developed,  forming  a  fossa  at  its  base. 

The  mesial  surface  (Fig.  31)  is  rounded  at  the  eminence,  flattened  at  the 
cervical  third,  and  nearly  straight  with  the  surface  of  the  root,  which  gives 
the  crown  the  appearance  of  being  bent  backward  or  having  a  distal  in- 
clination. 

The  distal  surface  (Fig.  32)  is  quite  convex  and  the  disto-morsal  angle 
prominent ;  as  it  approaches  the  cervix  it  becomes  more  or  less  flattened, 
and  at  the  cervical  margin  may  present  a  slight  concavity. 

The  morsal  edge  presents  a  more  or  less  prominent  cusp  and  a  mesial 
and  a  distal  incisive  edge.     The  distal  edge  is  longer  than  the  mesial,  and 


12  OPERATIVE    DENTISTRY. 

slopes  away  rapidly  to  the  distal  angle.  Tlie  differences,  however,  are  not 
so  marked  as  in  the  superior  cuspids.  The  angles  are  pronounced,  but  the 
mesial  less  so  than  the  distal. 

The  cervix  is  generally  found  on  section  to  be  oval  in  form,  although 
sometimes  it  is  flattened  mesio-distally,  and  when  the  root  is  grooved  it 
may  present  a  modified  hour-glass  outline.  The  curves  of  the  enamel  line 
are  not  so  variable  as  in  the  incisors,  nor  the  termination  of  the  enamel 
quite  so  abrupt  as  in  the  superior  cuspids. 

The  root  is  long,  straight,  tapering,  and  flattened  mesio-distally.  It  is 
shorter  than  the  superior  cuspid,  and  not  infrequently  presents  a  decided 
depression  or  groove  upon  its  mesial  and  distal  surfaces,  showing  a  ten- 
dency towards  bifurcation.  The  apex  is  slender  and  sometimes  curved  in  a 
labial  direction. 

The  piilp-canal  has  the  same  general  outline  as  the  root,  and  when  the 
longitudinal  grooves  upon  the  mesial  and  distal  surfaces  are  deep,  the  canal 
is  constricted  in  the  middle,  making  it  more  or  less  difficult  to  enter  with 
instruments.  The  average  length  of  the  inferior  cuspids  is  one  inch  (2.53 
centimetres),  of  the  crown  0.40  inch  (1.01  centimetres),  and  the  root  0.60 
inch  (1.52  centimetres.) 

THE   BICUSPIDS. 

The  bicuspids,  or  premolars,  as  they  are  sometimes  termed,  are  the  fourth 
and  fifth  teeth  from  the  median  line,  and  are  situated  between  the  cuspid 
and  first  molar  teeth.  There  are  eight  bicuspids  in  a  normal  denture  of 
man,  two  upon  each  side  in  the  upper  and  lower  jaws.  The  one  which 
is  situated  next  to  the  cuspid  tooth  is  termed  the  Jirst  Mcuspid,  and  the  one 
located  between  the  first  bicuspid  and  the  first  molar  is  known  as  the  second 
Mcuspid.  The  term  Mcuspid  is  derived  from  the  Latin  M,  two,  and  cuspis,  a 
point, — two-pointed  or  bi-cusped  ;  a  tooth,  therefore,  with  two  cusps. 

Architecturally  the  bicuspid  tooth  is  formed  of  two  cones  fused  together. 
This  structure,  from  the  mechanical  stand-point,  is  weak  and  faulty,  as  its 
power  of  resistance  to  the  mechanical  force  applied  in  mastication  depends 
upon  the  strength  of  the  mesial  and  distal  marginal  ridges  which  bind  the 
cones  together  upon  the  morsal  surface ;  when  these  for  any  reason  have 
been  destroyed,  the  greatest  weakness  of  the  structure  is  developed,  ending 
in  the  separation  of  the  cones  under  stress  and  the  loss  of  one  or  both  cusps. 
Fractures  of  this  character  occur  more  frequently  in  the  bicuspids  on 
account  of  their  mechanical  weakness  than  in  any  of  the  other  teeth. 

The  bicuspids  succeed  and  replace  the  deciduous  molars,  and  by  reason 
of  their  smaller  size  give  extra  space  in  the  jaws  for  the  permanent  cuspids, 
which  are  much  larger  than  their  deciduous  predecessors,  and  are,  as  a 
rule,  erupted  at  a  later  period. 

The  function  of  the  bicuspids  is  to  divide  the  food  into  small  pieces 
and  prepare  it  to  be  triturated  by  the  molars. 

The  superior  first  bicuspids,  viewed  from  the  morsal  surface,  have 
the  form  of  a  rounded  quadrilateral,  the  buccal  margin  being  broader  than 
the  linguaL  Section  through  the  crown  just  beyond  the  cusi)s  shows  a 
somewhat  pear-shaped  outline.     The  design  of  this  form  is  to  make  it  pos- 


Mesin- 
niorsal 
edge 


Fig.  83. — Superior  right  first  bicuspid,  buccal  surface. 
(Enlarged.) 


Lingual  cusp 

Fig.  34. — Superior  right  first  bicuspid,  lingual  surface. 
(Enlarged.) 


Lingual  cusp 
Fig.  35.— Superior  right  first  bicuspid,  mesial  surface. 
(Enlarged.) 


Buccal  cusp 

Fig.  36. — Superior  liglit  first  bicuspid,  distal  surface. 
(Enlarged.) 


Buccal  triangular  ridf^e 


Lingual  cusp 
Fig.  37.— Superior  right  first  bicuspid,  morsal  surface. 
(Enlarged.) 


Fig.  38. — Superior  right  second  bicuspid,  buccal 
surface.     (Enlarged.) 


Lingual  cusp 
Fig.  39. — Superior  right  second  bicuspid,  lingual 
surface.     (Enlarged.) 


Fig.  40. — Superior  right  second  bicuspid,  mesial 
surface.    (Enlarged.) 


CLASSIFICATION    AND    DESCRIPTIVE    ANATOMY    OF    THE    TEETH.  13 

sible  for  these  teetli  to  follow  the  curve  of  the  alveolar  arch.  The  bucco- 
liugnal  diameter  of  the  crowu  is  about  one-third  greater  thau  its  mesio- 
distal  diameter. 

The  'buccal  surface  (Fig.  33)  of  the  crown  is  almost  a  counterpart  of 
the  corresponding  surface  of  the  superior  cuspid,  with  the  excei^tion  that 
the  cusp  is  placed  nearer  the  centre  of  the  crown,  thus  making  the  mesial 
and  distal  morsal  margins  nearly  of  the  same  length.  The  central  or 
buccal  ridge  which  springs  from  the  cusp  is  prominent,  while  the  mesial 
and  distal  ridges  or  lobes  are  rarely  conspicuous.  The  developmental 
grooves  or  furrows  between  them  are,  therefore,  shallow  and  extend  only 
about  half-way  to  the  cervix,  where  they  are  lost  in  the  smooth  convexity 
of  the  cervical  half  of  this  surface.  The  surface  is  considerably  narrower 
at  the  cervical  margin,  which  gives  it  the  general  outline  of  a  cone,  with 
the  apex  at  the  cervical  margin.  This  difference  in  the  width  of  the 
buccal  surface  at  the  angles  and  at  the  cervix  gives  the  "^bell-shaped" 
form  to  these  teeth. 

The  lingual  surface  (Fig.  34)  is  mesio-distally  regularly  convex.  From 
the  lingual  cusp  to  the  cervix  it  presents  a  nearly  straight  line,  though 
many  times  it  is  slightly  convex,  and  occasionally  fully  as  much  so  as  the 
buccal  surface.  Mesio-distally  the  surface  is  not  so  broad  as  the  buccal 
surface,  and  the  lingual  cusp  is  not  quite  so  long. 

The  mesial  surface  (Fig.  35)  bucco-lingually  is  much  flattened,  but 
slightly  convex  ;  from  the  mesio-morsal  marginal  ridge  to  the  cervix  it  is 
also  slightly  convex,  although  examples  are  numerous  in  which  a  shallow 
concavity  is  presented  at  the  cervical  margin,  which  extends  to  the  side 
of  the  root  in  a  more  or  less  sharj^ly  defined  groove.  The  marginal  angles 
formed  by  the  union  of  this  surface  with  the  buccal  and  morsal  surfaces 
are  well  defined,  but  the  mesial  and  lingual  surfaces  are  so  blended  and 
rounded  that  it  is  difficult  to  designate  their  line  of  union  as  an  angle. 

The  distal  surface  (Fig.  36)  is  so  nearly  like  the  mesial  surface  that  it 
needs  no  especial  description  except  in  the  points  of  difference.  It  is 
rather  more  convex  than  the  mesial  surface,  has  rarely  a  convexity  at  the 
cervical  margin,  and  the  disto-morsal  angle  is  more  prominent  than  the 
mesio-morsal. 

The  morsal  or  occlusal  surface  (Fig.  37)  presents  an  abrupt  change  in 
form  and  function  as  compared  with  the  morsal  edge  of  the  cuspid  tooth. 
This  surface  is  composed  of  two  well-defined  cusps  or  points  divided  by 
a  deep  sulcus  having  a  mesio-distal  direction,  and  bound  together  at  their 
bases  mesially  and  distally  by  two  strong  and  prominent  ridges  termed  the 
mesio-morsal  and  the  disto-morsal  ridges. 

One  of  these  cusps  is  situated  at  the  buccal  margin,  and  the  other  at  the 
lingual,  and  from  their  situation  are  designated  as  the  buccal  and  the  lingual 
cusps.  The  buccal  cusp  is  usually  sharper,  longer,  and  more  prominent 
than  the  lingual  cusp.  The  lingual  cusp  is  broader  and  more  rounded. 
From  the  summit  of  the  buccal  cusp  four  ridges  slope  away  at  right  angles, 
one  mesially  to  form  the  mesio-morsal  edge  of  the  crown  ;  one  distally  to 
form  the  disto-morsal  edge ;  one  to  the  buccal  surface,  forming  the  central 
buccal  ridge,  and  another  slopes  downward  in  an  opposite  direction  to  form 


14  OPERATIVE    DENTISTRY. 

the  huccal  triangular  ridge,  whicli  ends  either  in  the  central  sulcus  or  joins 
a  similar  ridge  descending  from  the  summit  of  the  lingual  cusp,  and  forms 
the  transverse  ridge.  The  mesio-morsal  aud  disto-morsal  edges  enter  into 
the  formation  of  the  mesial  and  distal  morsal  angles  at  their  extremities. 

The  lingual  cusp  is  usually  blunt,  and  its  margins,  which  are  not  sharply 
defined,  unite  with  the  marginal  ridges  at  both  angles.  The  lingual  trian- 
gular ridge  arises  at  the  summit  of  the  lingual  cusp,  and  either  terminates 
at  the  central  sulcus  or  joins  its  fellow  of  the  buccal  cusp  to  form  the  trans- 
verse ridge.  The  lingual  triangular  ridge  is  seldom  prominent,  and  some- 
times is  entirely  absent. 

The  central  sulcus  extends  from  one  lateral  ridge  to  the  other  in  a  mesio- 
distal  direction,  and  widens  into  the  mesial  and  distal  sulci  at  each  end. 

The  mesial  and  distal  sulci  are  not  always  well  defined,  and  are  seen 
passing  over  the  central  portion  of  the  mesial  and  distal  marginal  ridges. 
The  mesial  and  distal  triangular  grooves  are  situated  at  the  base  of  the 
marginal  ridges,  and  are  directed  towards  the  mesial  and  distal  angles, 
dividing  the  marginal  ridges  from  the  triangular,  where  they  are  either 
lost  or  may  be  traced  as  slight  depressions  near  the  angles.  These  sulci 
often  become  the  seat  of  caries. 

The  cervix  is  flattened  laterally,  its  bucco-lingual  diameter  being  some- 
what greater  than  its  mesio-distal.  The  enamel  line  curves  slightly 
upward  at  the  buccal  and  lingual  cervical  margins,  and  dips  downward  a 
very  little,  or  may  describe  a  nearly  straight  line  at  the  mesial  and  distal 
cervical  margin. 

The  root  is  considerably  flattened  laterally,  and  is  generally  more  or 
less  deeply  grooved  from  the  cervix  to  the  apex,  and  often  bifurcated  for 
from  one-third  to  two-thirds  of  its  length.  The  root  over  the  buccal  cusp  is 
the  buccal  root,  and  that  over  the  lingual  cusp  is  termed  the  lingual  root. 
Bifurcated  roots  in  the  first  superior  bicuspid  is  the  rule  in  the  negro 
and  other  races  of  a  low  order  of  intelligeiice,  and  also  in  the  apes.  It  is 
often  very  crooked,  or  may  be  triple-rooted. 

The  pulp-canal  usually  takes  the  form  of  the  root,  and  may  be  either 
single  or  double.  It  is  narrow  at  the  neck,  and  often  constricted  in  the 
middle,  giving  it  the  outline  of  an  hour-glass.  More  often,  however,  it 
has  two  distinct  pulp-canals.  The  coronal  portion  of  the  canal  terminates 
in  two  well-defined  cornua  or  horns  which  point  towards  the  cusps  of 
the  crown. 

The  average  length  of  the  first  bicuspid  is  0.80  inch  (2.03  centimetres), 
of  the  crown  0.32  inch  (0.81  centimetre),  and  of  the  root  0.48  inch  (1.21 
centimetres). 

Tlie  superior  second  bicuspid  so  nearly  resembles  the  first  that  its 
diflerences  only  need  to  be  noticed.  It  is  in  every  way  a  little  smaller ; 
the  cusps  are  reduced,  while  the  lingual  cusp  equals  or  exceeds  the  buccal 
cusp  in  size  and  length.  The  marginal  ridges  are  broader,  and  the  morsal 
surface  more  flattened,  and  often  presents  several  shallow  wrinkles  or 
supplemental  grooves  and  ridges,  which  radiate  from  the  central  sulcus. 
The  triangular  ridges  are  often  united,  thus  increasing  the  strength  of  the 
tooth.     The  crown  is  narrower  mesio-distally,  and  the  cervix  more  oval, 


Buccal  cvisp 


Fig.  41. 


-Superior  right  second  bicuspid,  distal 
surface.     (Enlarged.) 


Lingual  cusp 
Fig.  42. — Superior  right  second  bicuspid,  morsal 
surface.     (Enlarged.) 


Buccal  ridge 


Transverse  ridge 


Fig.  43. — Inferior  right  first  bicuspid,  buccal  surface, 
(Enlarged.) 


Fig.  44.— Inferior  right  first  bicuspid  lingual  surface. 
(Enlarged.) 


Triangular  or  transverse  ridge 


Buccal  cusp 


Fig.  45. — Inferior  right  first  bicuspid,  mesial  surface.  Fig.  46. — Inferior  right  first  bicuspid,  distal  surface. 

(Enlarged.)  (Enlarged.) 


Buccal  cusp 


Buccal  cusp 


Buccal 

ridge 


Mesial 


Central 


Disto- 

morsal 

ridge 


Disto- 
margi 
ridge 


Distal 


Mcsio- 

maiginal 

ridge 


Lingual  rid.tre  or  cusp 
Fig.  47. — Inferior  right  first  bicuspid,  morsal  surface. 
(Enlarged.) 


Me>io- 

liiigual 

cusp 


Lingual  groove 
Fig.  48. — Inferior  right  second  bicuspid,  morsal 
surface.    (Enlarged.) 


CLASSIFICATION   AND   DESCRIPTIVE   ANATOMY   OF   THE   TEETH.  15 

while  the  cervico-marginal  line  curves  slightly  downward  upon  the  mesial 
surface  only.  The  greatest  difference  between  these  teeth  is  in  the  root, 
which  is  a  little  longer  than  the  first ;  very  rarely  bifurcated ;  is  much 
flattened  from  the  cervix  to  the  apex,  and  often  deeply  grooved  upon  the 
mesial  surface  at  the  apical  third,  (See  Figs.  38,  39,  40,  41,  and  42.) 
Occasionally  the  root  is  rounded  and  conical.  Crooked  roots  are  of  more 
frequent  occurrence  than  in  the  other  bicuspid,  and  it  has  a  tendency  to  be 
rotated  in  its  alveolus,  more  frequently  in  a  distal  than  in  a  mesial  direction. 

The  pulp-canal  is  usually  single,  and  gives  free  access  to  its  apex. 

The  average  length  of  the  tooth  is  0.84  inch  (2.13  centimetres).  The 
average  length  of  the  crown  is  0.29  inch  (0.73  centimetre),  and  of  the 
root  0.55  inch  (1.39  centimetres). 

THE   INFEEIOE   BICUSPIDS. 

These  teeth  occupy  the  same  relative  positions  in  the  lower  jaw  that  the 
superior  bicuspids  occupy  in  the  upper  jaw.  They  are  the  smallest  of  the 
bicuspid  teeth,  and  are  distinctive  in  form,  particularly  in  their  morsal 
surface.  The  transition  in  form  from  bicuspids  to  molars  is  more  marked 
in  the  lowers  than  in  the  uppers. 

In  the  inferior  first  bicuspid  the  lingual  cusp  is  rudimentary,  and  in  the 
second  it  is  large  and  broad,  and  divided  bucco-lingually  through  the 
centre  by  a  more  or  less  deep  furrow,  giving  it  the  appearance  of  a  tri- 
cuspid tooth. 

In  architectural  form,  these  teeth  are  constructed  from  a  single  cone, 
the  peculiarities  of  the  crown  being  the  result  of  various  additions  or 
cingules  to  the  primitive  cusp.  Unlike  the  superior  bicuspids,  the  buccal 
and  lingual  cusps  are  connected  by  a  transverse  ridge. 

The  Inferior  First  Bicuspid. — This  tooth  is  the  smallest  of  all  the 
bicuspids,  and  more  nearly  resembles  a  cuspid  than  a  bicuspid,  on  account 
of  the  imperfect  development  or  suppression  of  its  lingual  cusp,  which 
is  often  little  more  than  a  cingule.  In  general  outline  the  crown  is  much 
more  rounded  than  the  superior  bicuspids,  and  its  bucco-lingual  and 
mesio-distal  measurements  are  nearly  equal. 

The  buccal  surface  (Fig.  43)  viewed  from  the  buccal  aspect,  looks  like  a 
cuspid.  In  form  the  buccal  surface  is  a  long  oval,  surmounted  by  an 
acute  point.  It  is  convex  in  all  directions.  The  buccal  cusp  is  situated 
a  little  to  the  distal  of  the  centre  of  the  crown,  while  the  curvature  of  the 
buccal  surface  towards  the  lingual  side  places  the  buccal  cusp  nearly  in  a 
central  position  to  the  long  axis  of  the  tooth. 

The  lingual  surface  (Fig.  44)  is  convex  mesio-distally,  and  nearly  straight 
from  cervix  to  morsal  margin.  The  tooth  is  slightly  bent  at  the  cervix 
in  a  lingual  direction,  which  gives  the  crown  a  lingual  inclination.  The 
length  of  this  surface  depends  upon  the  length  of  the  lingual  cusp  or 
cingule  ;  usually  it  is  only  about  half  as  long  as  the  buccal  surface. 

The  mesial  and  distal  surfaces  (Figs.  45  and  46)  are  convex  bucco- 
lingually,  slightly  flattened  at  the  cervix,  and  becoming  convex  towards 
the  morsal  margin,  which  gives  a  bell  shape  to  the  crown  when  viewed  from 
the  buccal  aspect. 


16  OPERATIVE    DENTISTRY. 

Tlie  morsal  surface  (Fig.  47)  is  so  different  from  the  sujDerior  first  bicus- 
pid that  a  separate  description  is  necessary.  In  general  outline  tliis  surface 
approaches  a  rounded  triangle,  tlie  width  at  the  buccal,  mesial,  and  distal 
margins  being  greater  than  at  the  lingual  margin.  It  is  surmounted  by  a 
prominent  buccal  cusp  which  is  located  nearly  in  the  centre  of  the 
surface,  and  a  small  lingual  cusp,  though  this  is  sometimes  entirely 
absent,  and  its  place  occupied  by  a  more  or  less  prominent  lingual  ridge. 
The  buccal  cusp  has  four  well-defined  ridges  descending  from  it  like  those 
of  the  superior  first  bicuspid.  The  buccal  ridge  arises  from  the  summit 
of  the  cusp  and  descends  to  the  buccal  surface ;  the  mesial  and  distal 
morsal  ridges  usually  form  a  curve  with  its  concavity  towards  the  lingual, 
and  are  merged  into  the  marginal  ridges  to  form  rounded  angles  ;  the  tri- 
angular or  transverse  ridge  descends  towards  the  lingual  cusp  or  ridge. 
On  either  side  of  this  ridge  are  pits,  the  mesial  and  distal  pits.  The  mar- 
ginal ridges  are  usually  well  defined.  The  central  groove  sometimes 
crosses  the  transverse  ridge  ;  at  other  times  the  ridge  is  divided  by  a  deep 
sulcus. 

The  cervix  is  very  much  constricted,  and  the  cervical  line  but  slightly 
curved  except  at  the  buccal  margin.  The  enamel  at  this  point  sometimes 
forms  a  prominent  ridge. 

The  root  is  single,  flattened  laterally,  long  and  slender,  occasionally 
grooved  mesio-distally,  is  rarely  bifurcated,  and  inclined  to  be  crooked. 

The  pulp-canal  is  small  and  flattened,  and  difiicult  of  access.  The  diffi- 
culties are  increased  by  the  lingual  inclination  of  the  crown  and  the  ten- 
dency of  the  root  to  be  crooked. 

The  average  length  of  the  inferior  first  bicuspid  is  0.84  inch  (2.13  cen- 
timetres), of  the  crown  0.30  inch  (0.76  centimetre),  and  of  the  root  0.54 
inch  (1.37  centimetres). 

The  inferior  second  bicuspid  resembles  the  first  so  closely  in  general 
form  of  both  the  crown  and  the  root  that  an  especial  description,  except 
of  its  morsal  surface,  would  be  unnecessary. 

The  morsal  surface  (Fig.  48)  of  the  tooth  presents  the  most  marked  devia- 
tion in  form  of  any  of  the  bicuspid  teeth.  It  is  triangular  in  outline,  like 
the  first,  but  a  trifle  larger.  The  buccal  cusp  is  larger  and  rounded  ;  the 
lingual  cusp  not  quite  so  fully  developed,  and  divided  bucco-lingually, 
through  the  centre,  by  a  deep  groove,  which  gives  the  crown  the  appear- 
ance of  being  a  tricuspate.  The  mesio-lingual  cusp  or  tubercle  is  some- 
times develoiDcd  at  the  expense  of  the  disto-lingual,  but  it  is  always 
present.  Occasionally  it  appears  as  a  mere  cingule  on  the  disto- marginal 
ridge.  A  well-defined  triangular  ridge  descends  from  each  of  the  cusps, 
and  terminates  at  the  central  groove. 

The  marginal  ridges  are  well  marked.  The  central  groove  is  generally 
straight,  but  often  curved  or  angular  ;  the  lingual  groove  is  straight,  and 
united  with  the  central  groove,  forming  at  the  point  of  union  the  central 
fossa.     The  other  surfaces  are  shown  in  Figs.  49,  50,  51,  and  52. 

The  average  length  of  the  inferior  second  bicuspid  is  0.87  inch  (2.20 
centimetres),  of  the  crown  0.31  inch  (0.78  centimetre),  and  of  the  root 
0.56  inch  (1.42  centimetres). 


Buccal  cusp 


Fig.  49.- 


-Inferior  right  second  bicuspid,  buccal 
surface.     (Enlarged.) 


FtG.  50. — Inferior  right  second  bicuspid,  lingual 
surface.     (Enlarged.) 


Buccal  cusp 


Fig.  .51. — Inferior  right  second  bicuspid,  mesial 
surface.     (Enlarged.) 


Fig.  52. — Inferior  right  second  bicuspiid,  distal  surface. 
(Enlarged.) 


Mesio- 
buceal 
cusp 


Buccal  groove 
Pig.  53. — Superior  right  first  molar,  buccal  surface. 
(Enlarged.) 


Mesio- 

buceal 

root 

Lingual 

develoj)- 

mental 

lobe 

Mesio- 

lingual 

cusp 

bl 

Disto- 
liuecal 
root 

Lingual 
root 


Lingual 
develop- 
mental 
lobe 

Disto- 

lingual 

cusp 


Lingual  groove 

Fig.  54. — Sujjerior  right  first  molar,  lingual  surface. 
(Enlarged.) 


Mesio- 

buccal 

cusp 


Mesio- 
lingual 
cusp 


Pig.  55. — Superior  right  first  molar,  mesial  surface. 
(Enlarged.) 


Disto-lingual  cusp  Disto-buccal  cusp 

Fig.  56. — Superior  right  first  molar,  distal  surface. 

(Enlarged.) 


CLASSIFICATIOX   AND   DESCRIPTIVE   ANATOMY   OF   THE   TEETH.  17 


THE   MOLARS. 

The  molars,  or  tuberculate  teeth,  as  they  are  sometimes  termed,  are  very 
different  in  form  and  architectural  design  from  those  which  have  been  pre- 
viously described.  The  most  simple  form  of  tooth  is  that  designed  from 
the  single  cone.    This  is  the  architectural  form  of  the  incisors  and  cuspids. 

The  bicuspids  are  more  complex,  being  formed  of  two  cones.  But  the 
inferior  first  bicuspid  has  but  one  well-developed  cusp  and  a  lingual  cin- 
gule.  The  superior  bicuspids  have  two  well-developed  cusps,  and  the 
inferior  second  bicuspids  have  three  cusps. 

The  superior  molars  are  still  more  comj)lex,  being  formed  by  the  addition 
of  a  third  cone  to  the  bicuspid  type.  This  gives  the  tooth  thi-ee  roots, 
upon  which  three  or  four  cusps  are  supported. 

The  inferior  molars  are  the  most  complicated  in  form  of  all  the  teeth, 
being  composed  of  four  cones  supporting  four  or  five  cusps. 

There  are  twelve  molars  in  man,  three  upon  either  side  of  each  jaw, 
above  and  below.  They  are  situated  in  the  i^osterior  part  of  the  jaws, 
behind  the  bicuspids,  and  are  designated  as  the  Jirst,  second,  and  tJdrd 
molars.  The  third  molar  is  sometimes  termed  the  dens  sapientia,  or  wis- 
dom-tooth, because  of  its  late  erui^tion.  The  molars  occupy  the  sixth, 
seventh,  and  eighth  places,  respectively,  from  the  median  line ;  the  first 
molar  approximating  the  second  bicuspid  distally,  the  second  molar  a.])- 
proximating  the  first  molar  distally,  and  the  third  molar  occupying  a 
similar  i)Osition  to  the  second  molar.  The  function  of  the  molars  is  to 
crush  and  triturate  the  food,  and  fit  it  to  be  acted  upon  by  the  gastric  juice 
of  the  stomach.  The  loss  of  these  teeth,  therefore,  seriously  impairs  the 
function  of  mastication,  and  inevitably  leads  to  various  derangements  of 
digestion,  and  these  again  to  imperfect  assimilation  and  nutrition.  The 
preservation  of  these  teeth,  therefore,  becomes  of  vital  importance  to  the 
individual. 

The  superior  first  molar  is  located  upon  the  distal  side  of  the  second 
bicuspid.  It  is  the  largest  and  most  strongly  marked  of  the  superior 
molars,  and  may  therefore  be  taken  as  the  typical  form.  It  possesses  three 
strong  roots,  and  the  crown  is  surmounted  by  four  more  or  less  prominent 
cusps.  In  general  contour  the  crown  is  an  irregular  quadrilateral,  having 
its  angles  rounded,  two  of  its  sides  convex,  and  two  slightly  fiattened. 
The  bucco-lingual  diameter  is  a  little  greater  than  the  mesio-distal,  while 
the  height  of  the  crown  is  about  equal  to  the  mesio-distal  diameter.  It 
presents  for  examination  five  surfaces, — buccal,  lingual,  mesial,  distal, 
and  morsal. 

The  buccal  surface  (Fig.  53)  is  formed  by  the  union  of  the  mesio-  and 
disto-buccal  developmental  lobes,  and  is  divided  by  the  buccal  groove  into  a 
mesial  and  a  distal  half,  which  are  quite  similar  in  outline.  This  surface 
is  about  twice  the  width  of  the  bicuspids.  It  is  widest  at  the  morsal 
margin,  narrowing  towards  the  cervix,  giving  a  bell  shape  to  the  tooth. 
The  morsal  margin  is  surmounted  by  the  mesio-  and  disto-buccal  cusps, 
which  are  separated  by  a  deep  notch,  through  which  passes  the  buccal 
groove  to  the  cervical  margin.     Sometimes  this  groove  terminates  in  a  pit 

2 


18  OPERATIVE    DENTISTRY. 

midway  between  the  morsal  and  cervical  margin.  Descending  from  eacli 
buccal  cusp  is  a  longitudinal  ridge, — the  buccal  rklges, — wliicli  are  at  first 
well  defined,  but  gradually  disappear  in'  tlieir  course  towards  tbe  cervix. 

The  Ungual  surface  (Fig.  54),  like  the  buccal  surface,  is  formed  by  the 
union  of  the  two  lingual  developmental  lobes,  and  is  divided  into  a  mesial  and 
a  distal  half  by  the  Ungual  groove.  Both  halves  are  smoothly  convex  in  all 
directions.  The  morsal  margin  is  surmounted  by  the  mesio-  and  disto- 
lingual  cusps,  the  mesial  being  the  larger.  The  mesial  lobe  often  carries  a 
tubercle  or  cingule, — a  rudimentary  fifth  cusp.  The  mesial  and  distal 
margins  converge  rapidly  towards  the  cervix,  conforming  to  the  palatal 
root. 

The  mesial  surface  (Fig.  55)  is  nearly  flat,  except  near  the  morsal  margin, 
where  it  is  slightly  convex,  and  at  the  cervical  margin,  where  it  is  some- 
times depressed  towards  the  lingual  or  palatal  root.  The  buccal  and  lingual 
margins  are  rounded.  The  morsal  margin  is  concave  in  the  direction  of 
the  root,  while  the  cervical  margin  is  concave  in  the  direction  of  the 
morsal  surface. 

The  distal  surface  (Fig.  56)  is  similar  to  the  mesial  surface,  except  that  it 
presents  a  somewhat  greater  convexity,  converging  more  sharply  towards 
the  cervix,  and  more  rounded  towards  the  lingual  root. 

The  morsal  surface  (Fig.  57)  is  surmounted  by  four  rounded  cusps  or 
tubercles  designated  as  the  mesio-buccal,  the  disto-buccal,  the  mesio-lingual, 
and  the  disto-Ungual  cusp  ;  the  latter  being,  as  a  rule,  smaller  than  the 
others,  and  sometimes  only  appearing  as  a  small  tubercle.  The  surface  is 
bounded  by  four  marginal  ridges  of  nearly  equal  length, — the  buccal,  the 
lingual,  the  mesial,  and  the  distal, — which  unite  the  bases  of  the  cusps. 

Arising  from  each  cusp  and  descending  towards  the  centre  of  the  tooth 
is  a  triangular  ridge.  The  triangular  ridges  of  the  mesio-lingual  and  disto- 
buccal  cusps  unite  to  form  the  prominent  oblique  ridge. 

On  the  mesial  and  distal  sides  of  the  oblique  ridge  are  two  fossae,  the 
central  and  distal.  The  bottom  of  the  central  fossa  is  deeply  lined  by  two 
of  the  developmental  grooves,  the  mesial  and  buccal  grooves.  The  former 
arises  on  the  mesial  surface,  crosses  the  mesio-marginal  ridge,  and  continues 
in  an  irregular  line  to  the  bottom  of  the  fossa  ;  the  latter  begins  upon  the 
buccal  surface,  crosses  the  bucco-marginal  ridge,  and  terminates  also  in  the 
central  fossa,  thus  forming  the  mesio-buccal  triangular  groove.  A  supple- 
mental groove  arises  from  the  central  pit  of  this  fossa,  extending  distally 
across  the  oblique  ridge,  which  is  termed  the  distal  groove.  It  is  rarely 
well  defined,  but  occasionally  it  may  divide  the  oblique  ridge. 

The  distal  fossa  is  not  so  large  as  the  central,  and  is  of  an  entirely  differ- 
ent form,  partaking  more  of  the  outline  of  the  sulcate  groove.  This  fossa 
is  traversed  by  a  deep  developmental  groove,  the  disto-Ungual  groove,  which 
arises  on  the  distal  margin,  follows  the  line  of  the  fossa,  crosses  the  lingual 
margin,  extending  on  to  the  lingual  surface  to  form  the  lingual  groove. 

When  a  fifth  cusp  is  present — the  mesio-lingual — it  is  separated  from  the 
lingual  surface  by  a  groove  designated  as  the  mesio-lingual  groove.  Various 
supplemental  grooves  or  wrinkles  are  found  upon  the  morsal  surface  of  the 
molars,  which  radiate  from  these  fossae. 


Buccal  groove 


Lingual  groove 
Fig.  57. — Superior  right  first  molar,  morsal  surface. 
(Enlarged.) 


Lingual 

^^H 

root 

^^^IP^^^B 

Disto- 

^^^K^I^H 

buccal 

^^HHB  ^|Hk'  '^^^^^^^H 

root 

^Hp^I 

W^^^B^fwr"^"" '     ^^^^1 

Mesio- 
buccal 
root 


Cervical 
margin 


Buccal  groove 
-Superior  right  second  molar,  buccal  surface. 
(Enlarged.) 


Disto- 

Mesio- 

buccal 

buccal 

root 

root 

Lingual  groove 
Fig.  59. — Superior  right  second  molar,  lingual  surface. 
(Enlarged.) 


Fig.  60. — Superior  right  second  molar,  mesial  surface. 
(Enlarged.) 


Huecal  Kri)i)ve 


Lingua 
loot 


Disto- 
buccal 

I'OOt 


Disto-liiigual  groove 
Fig.  61. — Suiif  rior  right  second  molar,  distal  surface. 
(Enlarged.) 


marginal 
ridge 


Fig.  62. — Suyierior  right  second  molar,  niorsal  surface. 
(Enlarged.) 


Buccal  gniove 
Pig.  63. — Superior  right  third  molar,  buccal  surface. 
( Enlarged. ) 


Mesial 
groove 


Lingual  cusp 
Fig.  64. — Superior  right  third  molar,  lingual  surface. 
(Enlarged.) 


CLASSIFICATION    AND    DESCRIPTIVE   ANATOMY    OF    THE    TEETH.  19 

The  cervix  of  this  tooth,  on  section,  shows  the  form  of  a  rounded  rhom- 
boid, widest  upon  its  buccal  aspect.  The  cervical  line  is  nearly  straight 
upon  all  four  surfaces.  A  concavity  occurs  on  the  buccal  side  at  the  bifur- 
cation of  the  buccal  roots,  and  a  slight  depression  upon  the  mesial  and 
distal  sides,  with  an  inclination  towards  the  lingual  root. 

The  root  is  divided  into  three  prongs  or  radicles,  two  upon  the  buccal 
side,  which  are  small,  tapering,  and  either  flat  or  rounded,  the  mesio- 
buccal  and  disto-huccal,  and  one  upon  the  lingual  side,  large,  round,  and 
tapering,  the  lingual.  The  roots  are  usually  separated  ;  their  apices  stand 
wide  apart.  Occasionally,  however,  they  are  united  for  some  distance  by 
a  bridge  of  cementum  ;  this  most  frequently  occurs  with  the  buccal  roots. 
The  mesio-buccal  is  the  largest  of  the  buccal  roots.  All  of  the  roots  may  be 
more  or  less  bent  and  crooked. 

TJie  Fulp- Chamber  and  Canals. — The  pulp-chamber  is  large  and  divides 
into  three  branches,  one  for  each  root.  The  lingual  canal  is  the  largest,  and 
is  freely  entered  to  its  ax)ex,  except  in  those  cases  in  which  the  root  is  bent 
or  crooked.  The  mesio-buccal  is  the  next  largest  canal,  and  can  often  be 
entered  with  ease,  but  occasionally  it  is  small  and  narrow,  and  when  the 
root  is  crooked  it  often  becomes  difficult  or  impossible  to  follow  it.  The 
disto-buccal  canal  is  almost  always  so  small  and  fine  as  to  require  great 
skill  and  much  patience  to  iDroperly  cleanse  it  preparatory  to  filling.  Many 
times  the  canal  cannot  be  followed  to  the  apex  by  any  degree  of  skill  or 
patience,  thus  making  the  proi^er  treatment  and  filling  of  these  roots  one 
of  the  most  difficult  problems  in  the  whole  range  of  dental  XDractice. 

The  average  length  of  the  superior  first  molar  is  0.81  inch  (2.05  centi- 
metres), of  the  crown  0.30  inch  (0.76  centimetre),  and  of  the  root  0.51 
inch  (1.29  centimetres). 

The  superior  second  molar  is  so  nearly  the  counterpart  of  the  first 
molar  that  the  differences  in  its  form  need  only  be  described.  It  is  a  little 
smaller  than  the  first  molar,  not  so  nearly  quadrilateral  in  form,  but 
rhomboidal,  being  somewhat  compressed  mesio-distally. 

The  buccal  surface  (Fig.  58)  is  almost  identical  with  that  of  the  first 
molar.  A  slight  difference  is  noticed  in  the  mesio-distal  width  of  the  sur- 
face and  in  the  location  of  the  buccal  groove,  which  in  many  instances  is 
at  the  distal  third  rather  than  at  the  mesio-distal  centre. 

The  lingual  surface  (Fig.  59)  presents  a  greater  convexity  mesio-distally, 
and  i^articularly  so  fi^om  the  linguo-morsal  margin  to  the  cervix.  The 
lingual  groove  is  not  so  constant  in  its  location,  often  being  found  between 
the  mesio-distal  centre  and  the  extreme  of  the  distal  third  of  the  surface. 

The  mesial  and  distal  surfaces  (Figs.  60  and  61)  have  only  slight  differ- 
ences. The  mesial  is  inclined  to  be  concaved  bucco-lingually ;  into  this 
concavity  the  distal  surface  of  the  first  molar  closely  fits,  while  the  only 
difference  in  the  distal  surface  is  that  it  is  more  markedly  convex. 

The  Morsal  Surface. — The  most  marked  differences  in  the  character  of 
the  morsal  surface  (Fig.  62)  of  the  second  superior  molar  is  the  almost  con- 
stant tendency  to  the  suppression  of  the  disto-lingual  lobe.  This  carries 
the  oblique  ridge  farther  to  the  distal  side,  and  enlarges  the  central  fossa. 
The  cusps  are  also  not  so  prominent,  and  when  the  disto-lingual  cusx^  is 


20  opekatlVe  dentistry. 

only  rudimentary  in  size,  and  the  oblique  ridge  prominent,  the  tooth  be- 
comes practically  a  three-cusj)ed  tooth.  The  various  grooves  are  the  same 
as  on  the  first  molar  in  the  normally  developed  organ. 

The  cervix  is  less  regular  in  outline  and  more  constricted  and  flattened 
mesio-distally  than  in  the  first  molar. 

The  t^oots  are  the  same  in  number  and  general  form  as  in  the  first  molar  ; 
they  spread  less,  however,  and  are  quite  inclined  to  be  crooked  or  converge 
towards  each  other,  or  to  be  fused  together. 

Sometimes  the  buccal  roots  only  are  fnsed,  while  in  others  the  mesial 
and  lingual  are  joined,  or  all  of  the  roots  may  be  united  in  a  single  root, 
the  outlines  of  the  roots  being  marked  only  by  shallow  grooves. 

The  pulp-canals  in  a  normally  develoi)ed  superior  second  molar  are,  as 
a  rule,  smaller  and  more  difficult  to  enter  than  those  of  the  first  molar. 

When  the  roots  are  fused  together,  all  of  the  canals  may  coalesce, 
making  a  single  canal,  or  when  union  of  the  buccal  roots  takes  place  these 
canals  may  unite.  The  uncertainty,  however,  as  to  their  regularity  in 
form  adds  greatly  to  the  difficulties  to  be  surmounted  in  the  treatment. 

The  average  length  of  the  superior  second  molar  is  0. 79  inch  (two  centi- 
metres), of  the  crown  0.28  inch  (0.71  centimetre),  and  of  the  root  0.51  inch 
(1.29  centimetres). 

The  superior  third  molars  are  smaller  than  either  of  the  other  su- 
perior molars,  and  show  greater  deviations  from  the  normal  type,  being 
very  erratic  as  to  the  time  of  their  ax)pearance  and  in  their  form  and  struc- 
ture. It  is  the  eighth  from  the  median  line,  and  the  last  tooth  of  the  upper 
dental  arch.  This  tooth,  when  well  formed,  is  a  tricuspid,  the  disto-lingual 
cusp  being  suppressed.  The  oblique  ridge  then  becomes  the  disto-marginal 
ridge.     The  crown  is  triangular  in  form  and  the  angles  well  rounded. 

The  buccal  surface  (Fig.  63)  is  like  that  of  the  second  molar,  but  more 
rounded  and  the  lobes  less  strongly  marked  and  the  buccal  groove  shallow. 

The  lingual  surface  (Fig.  64)  is  usually  full  and  convex  in  all  directions. 
It  has  but  a  single  lobe  on  account  of  the  suppression  of  the  disto-lingual 
cusp. 

The  Mesial  and  Distal  Surfaces. — The  mesial  surface  resembles  the  same 
surface  of  the  second  molar  but  is  reduced  in  size,  while  the  distal  surface 
is  shorter  and  more  rounded  (Figs.  65  and  66). 

The  morsal  surface  (Fig.  67)  in  a  well-developed  third  molar  presents  a 
7nesio-buccal,  a  disto-buccal,  and  a  mesio-Ungual  cusp,  with  the  suggestion  of 
a  disto-lingual  cusp,  in  the  form  of  a  cingule  or  tiny  tubercle.  In  this  case 
it  will  also  present  a  central  and  distal  fossa,  with  the  developmental 
grooves  more  or  less  distinctly  marked.  More  often,  however,  the  disto- 
lingual  cusp  is  entirely  suppressed,  and  with  it  the  distal  fossa.  Many 
times  the  cusps  will  be  so  blunted  around  the  central  fossa  as  to  give  the 
appearance  of  a  continuous  marginal  ridge,  occasionally  sharply  defined, 
or  it  may  be  broadly  rounded. 

The  cervix  is  constricted,  and  in  form,  on  section,  gives  the  outline  of  a 
rounded  triangle. 

The  roots  have  very  rarely  the  form  of  the  typical  molar  in  the  higher 
civilized  races.     As  a  rule,  the  roots  are  fused  too-ether  to  a  greater  or  less 


Mesial  groove 
Fig.  65. — Superior  right  third  molar,  mesial  surface. 
(Enlarged.) 


Distal  groove 
Fig.  66. — Superior  right  third  molar,  distal  surface. 
(Enlarged.) 


Buccal  groove 


Disto-buccal  groove 


Buccal  groove 


Mesio-lingual  cusp 
Fig.  67. — Superior  right  third  molar,  morsal  surface. 
(Enlarged.) 


Fig. 


B. — Inferior  right  first  molar,  buccal  surface. 
(Enlarged.) 


Mesio-linjfual  cusp  ])ist()-liii!Jual  cusp 


Lingual 
groove 


v! 

1    '  -'■ 

Disto- 
morsal 
Biarffin 


Fig.  69. — Inferior  right  first  molar,  lingual  surface. 
(Enlarged.) 


Fig.  70. — Inferior  right  first  molar,  mesial  surface. 
(Enlarged.) 


Median- 
Buccal  groove    buccal  cusp       Disto-huccal  groove 


Fig.  71.— Inferior  right  first  molar,  distal  surface. 
(Enlarged.) 


Lingual  groove 
Fig.  72. — Inferior  right  first  molar,  morsal  surface. 
(Enlarged.) 


CLASSIFICATION   AND    DESCRIPTIVE   ANATOMY   OF   THE   TEETH.  21 

extent,  sometimes  forming  a  single  root,  and  they  are  often  curved  distally 
towards  the  maxillary  tubei'osity.  Sometimes  they  have  multiple  roots, 
which  may  be  curved  in  various  directions. 

The  pulp-canals  are  usually  blended  into  one,  but  when  the  roots  are 
separate  there  are  individual  canals.  The  difficulties  presented  in  the 
treatment  of  the  root- canals  of  these  teeth  are  greatly  enhanced  by  the 
positions  which  they  occuiDy  in  the  jaw  and  their  great  liability  to  have 
crooked  roots. 

The  average  length  of  the  superior  third  molar  is  0.68  inch  (1.72  centi- 
metres), of  the  crown  0.24  inch  (0.6  centimetre),  and  of  the  root  0.44  inch 
(1.11  centimetres). 

THE   INFEEIOE,   MOLARS. 

The  inferior  molars  are  three  in  number,  and  are  designated  according 
to  their  positions  in  the  jaw  as  the  first^  the  second^  and  the  third.  They 
occupy  respectively  the  sixth,  seventh,  and  eighth  positions  in  the  inferior 
arch  from  the  median  line. 

As  already  stated,  these  teeth  are  constructed  upon  the  architectural  de- 
sign of  a  combination  of  four  cones  united  at  their  bases  to  form  the  crown, 
while  the  apices  are  united  in  pairs  to  form  the  mesial  and  distal  roots. 

The  inferior  molars  differ  from  the  suj^erior  in  that  they  have  two 
roots  instead  of  three  ;  are  inclined  to  have  multiple  cusps ;  have  a 
greater  diameter  mesio- distally  than  bucco-lingually  ;  and  the  buccal 
surface  slopes  towards  the  centre  of  the  tooth  to  accommodate  the  over- 
locking  of  the  cusps  of  the  occluding  teeth. 

The  inferior  first  molar  is  the  sixth  tooth  from  the  median  line,  and 
approximates  the  second  bicuspid  u^^on  its  distal  surface,  ^'l^exttothe 
superior  first  molar  it  is  the  largest  tooth  in  the  denture."     (Black.) 

The  buccal  surface  (Fig.  68)  is  an  irregular  trapezoid  in  form,  the  morsal 
margin  being  wider  than  the  cervical,  due  to  the  convergence  of  the  mesial 
and  distal  surfaces  towards  the  cervix.  The  surface  is  convex  in  all  direc- 
tions, and  the  mesial  and  distal  margins  are  rounded.  The  morsal  margin 
is  usually  surmounted  by  three  cusps  or  tubercles,  the  mesio-buccal,  the  me- 
dian-huccal,  and  tine  disto-huccal,  which  are  separated  by  the  buccal  and  disto- 
buccal  grooves.  The  buccal  groove  is  a  little  to  the  mesial  of  the  centre  of 
the  tooth,  while  the  disto-buccal  groove  is  near  the  disto-buccal  angle. 
These  grooves  generally  terminate  near  the  middle  of  the  surface  in  pits, 
which  often  become  the  seat  of  caries. 

The  lingual  surface  (Fig.  69)  is  slightly  convex  in  all  directions,  and  in- 
clines towards  the  lingual.  The  surface  is  not  so  wide  as  the  buccal  sur- 
face on  account  of  the  convergence  of  the  mesial  and  distal  surfaces  towards 
the  lingual.  The  morsal  margin  forms  a  rather  sharp  angle  with  the  mor- 
sal surface  ;  it  is  surmounted  by  two  cusps  or  tubercles,  the  mesial  and  dis- 
tal, and  is  divided  through  its  centre  by  the  lingual  groove,  which  separates 
the  mesial  and  the  distal  cusx)S.  This  groove  is  shallow  and  rarely 
extends  farther  than  the  middle  of  the  surface. 

The  mesial  and  distal  surfaces  (Figs.  70  and  71)  are  flattened  bucco-lin- 
gually and  convex  from  morsal  margin  to  cervix,  the  distal  surface  more 
than  the  mesial.     They  are  wider  at  the  morsal  margin  than  at  the  cervix. 


22  opp:rative  dentistry. 

The  mesio-morsal  margiu  is  deeply  concaved,  and  the  disto-morsal  margin 
is  notched,  sometimes  deeply,  by  the  distal  groove. 

The  morsal  surface  (Fig.  72)  is  trapezoidal  in  form,  the  buccal  side  being 
the  longest.  The  surface  is  surmounted  by  five  cusps,  designated  as  fol- 
lows :  the  7iiesio-buccal,  the  median-huccal,  the  dlsto-buccal,  the  mesio-lingual, 
and  the  disto-Ungual ;  three  are  arranged  upon  the  buccal  half  of  the  sur- 
face, and  two  upon  the  lingual.  The  cusps  are  united  at  their  bases  by 
four  marginal  ridges,  the  mesio-marginal  ridge,  joining  the  mesio-buccal  and 
the  mesio-lingual  cusps  ;  the  hucco-marginal  ridge,  uniting  the  mesio-buccal,, 
median-buccal,  and  disto-buccal  cusps ;  the  linguo-marginal  ridge,  joining 
the  mesio-lingual  and  disto-lingual  cusps ;  and  the  disto-marginal  ridge, 
uniting  the  disto-lingual  and  disto-buccal  cusps.  These  ridges  slope 
towards  the  centre  of  the  teeth  to  form  the  central  fossa.  There  are  five 
triangular  ridges  which  descend  from  the  five  cusps  towards  the  centi-al 
fossa.  The  morsal  surface  is  traversed  by  five  developmental  grooves, 
the  mesial,  buccal,  disto-buccal,  lingual,  and  distal. 

The  mesial  groove  arises  in  the  central  fossa  and  crosses  the  mesio-margi- 
nal ridge  to  the  mesial  surface ;  the  buccal  groove  begins  at  the  central  fossa, 
crosses  the  bucco-marginal  ridge  between  the  mesio-  and  median-buccal 
cusps  to  the  buccal  surface  ;  the  disto-huccal  groove  takes  a  disto-buccal  di- 
rection from  the  central  fossa,  dividing  the  bucco-marginal  ridge  between 
the  median-  and  disto-buccal  cusps  ;  the  lingual  groove  has  its  origin  in  the 
central  fossa,  crosses  the  linguo-marginal  ridge  in  a  deep  sulcus  between  the 
mesio-  and  disto-lingual  cusps,  and  is  lost  uiDon  the  lingual  surface. 

The  distal  groove  arises  also  from  the  central  fossa,  crosses  the  disto- 
marginal  ridge  dividing  the  disto-lingual  cusp  from  the  disto-buccal. 
Various  other  pits  and  supplemental  grooves  are  occasionally  observed. 

The  cervix  on  section  is  rectangular  in  form,  with  the  sides  slightly  con- 
caved in  the  centre,  and  deepest  at  the  buccal  and  lingual  sides  at  the  begin- 
ning of  the  bifurcation  of  the  roots.  The  cervical  line  is  convex  upon  the 
buccal  and  lingual  sides,  and  concave  upon  the  mesial  and  distal. 

The  roots  are  two  in  number,  the  mesial  and  the  distal.  They  are 
long,  flattened  mesio-distally,  and  often  have  a  decided  distal  curvature. 
They  are  implanted  in  their  alveoli,  with  their  long  diameter  in  a  trans- 
verse direction  to  the  jaw.  The  distal  root  is  larger  and  more  rounded 
than  the  mesial,  the  latter  having  deeper  grooves  and  a  greater  tendency 
to  bifurcation. 

The  pulp-canal  is  formed  like  the  teeth,  with  two  branches.  Occa- 
sionally the  mesial  root  will  have  two  canals.  The  distal  canal  is  the 
largest  and  quite  readily  entered,  while  the  mesial  canal  is  inclined  to  be 
flat  or  hour-glass-shaped,  showing  the  tendency  of  this  root  to  bifurcate. 

When  separate  canals  are  formed,  they  are  usually  very  small,  and 
often  cannot  be  followed. 

The  average  length  of  the  inferior  first  molar  is  0.82  inch  (2.08  centi- 
metres), of  the  crown  0.30  inch  (0.76  centimetre),  and  of  the  root  0.52 
inch  (1.32  centimetres). 

The  inferior  second  molar  differs  from  the  first  in  that  it  has  but  four 
instead  of  five  cusjds,  is  more  quadrangular,  rounded,  and  symmetrical. 


Buccal 
Mesio-buccal  cusp    groove   Mesio-lingual  cusp 


Central  fossa 


Mesio- 
l)uccal 

Mesio- 

lingual 

cusp 

cusp 

Lingual 

Buccal 

pit; 

groove 

Mesial 
root 


Fig.  73.— Inferior  right  second  molar,  buccal  surface.         Fig.  7i.— Inferior  right  second  molar,  lingual  surface. 
(Enlarged.)  (Enlarged.) 


Mesial  groove 


Distal  groove 


Disto- 

lingual 

cusp 


< 


Disto- 
huccal 
cusp 


Fig.  75. — Inferior  right  second  molar  mesial  surface. 
(Enlarged.) 


Fig.  76. — Inferior  right  second  molar,  distal  surface. 
(Enlarged.) 


Xi'siiil  KHxiyo 


Median 
Pisto-linKual  cusp    Ijuecal  cusp     Mesio-liuccal  cusp 


Mesio- 
Imccal 
cusp 

l)ist(.- 
buccal 

CUSJI 

Buccal 
inarKinal 
1  i<iKe 

Buccal 
groove 

Difeto- 
Ijuccal 
cusp 

Distal 
root 

Central  fossa  Distal  pit 

Fig.  77.— Inferior  riKht  second  molar,  morsal  surface. 
(Enlarged.) 


Fig.  7.S. — Inferior  right  third  molar,  buccal  surface. 
(Enlarged.) 


Mesio-buccal  cusp  Disto-lingual  cusp 


Mesial  groove 


Fig.  79. — Inferior  right  tliird  molar,  lingual  surface.  Fig.  80. — Inferior  right  third  molar,  mesial  surface. 

(Enlarged.)  (Enlarged.) 


CLASSIFICATION   AND    DESCRIPTIVE   ANATOMY   OF   THE   TEETH.  23 

The  huccal  surface  (Fig.  73)  is  convex  in  all  directions,  but  is  divided 
into  two  lobes  by  tbe  buccal  groove,  which  is  usually  shallow.  A  deep 
buccal  pit  is  often  observed  in  the  centre  of  the  surface.  The  morsal  mar- 
gin slopes  towards  the  centre  of  the  tooth  as  in  the  first  molar,  and  the 
surface  is  widest  at  this  point,  while  the  convergence  of  the  mesial  and 
distal  surfaces  makes  it  narrowest  at  the  cervix. 

The  lingual  surface  (Fig.  74)  is  similar  to  that  of  the  first  molar,  with 
the  exception  that  it  is  proportionately  wider,  being  nearly  as  broad  as 
the  buccal. 

The  mesial  and  distal  surfaces  (Figs.  75  and  76)  are  similar  to  those  of 
the  first  molar,  except  that  the  distal  surface  does  not  have  the  distal  iDro- 
tuberance  due  to  the  presence  of  the  fifth  cusp  ;  both  surfaces  are  smoothly 
convex. 

The  morsal  surface  (Fig.  77)  is  surmounted  by  four  cusps,  placed  at  the 
four  corners  of  the  surface.  The  cusps  are  rounded  and  symmetrical,  the 
lingual  being  a  little  more  pointed  than  the  buccal.  The  marginal  ridges 
are  well  formed  and  enclose  a  central  fossa.  The  central  fossa  is  traversed 
by  four  developmental  grooves,  all  arising  from  the  central  pit,  which 
cross  the  four  marginal  ridges.  The  triangular  ridges  are  well  marked, 
being  more  j^rominent  than  in  the  first  molar. 

The  cervix  is  similar  to  that  of  the  first  molar,  but  more  constricted. 
The  cervical  line  describes  about  the  same  irregular  curves. 

The  roots  are  about  the  same  as  the  first  molar,  except  that  the  diver- 
gence is  not  so  great.  There  is  also  a  tendency  to  fusion  of  the  roots. 
Examples  of  complete  fusion  are  not  rare.  The  roots  are  usually  curved 
distally,  or  otherwise  crooked. 

The  pidp-canals  are  similar  to  those  of  the  first  inferior  molar,  the  distal 
the  largest,  and  the  mesial  usually  much  constricted.  The  same  difficulties 
are  encountered  in  opening  the  canals  as  are  found  in  the  first  molars, 
which  are  augmented  by  the  irregularity  in  the  form  of  the  roots. 

The  average  length  of  the  inferior  second  molar  is  0.77  inch  (1.95  cen- 
timetres), of  the  crown  0.27  inch  (0.68  centimetre),  and  of  the  root  0.50 
inch  (1.26  centimetres). 

The  inferior  third  mol-ar  is  similar  in  many  respects  to  the  other  lower 
molars.  It  is  the  eighth  from  the  median  line,  and  the  last  tooth  in  the 
lower  dental  arch.  It  approximates  the  second  molar  upon  its  distal  sur- 
face. It  is  probably  the  most  erratic  in  its  form  of  any  tooth  in  the  whole 
dental  series.  There  are  tioo  typical  forms,  one  having  four  cusps,  and  sepa- 
rated by  four  developmental  grooves,  like  the  second  molar,  and  the  other 
having  five  cusps  andfive  developmental  grooves  like  the  inferior  first  molar. 
While  these  two  forms  are  the  most  common,  there  are  many  variations 
from  these  types  ;  the  morsal  surface  is  often  divided  by  numerous  develop- 
mental grooves,  so  that  six,  seven,  and  even  eight  well-defined  cusps  are 
presented. 

The  huccal  surface  (Fig.  78)  of  this  tooth  is  more  convex  than  either  the 
first  or  second  molars,  but  in  all  other  respects  it  has  the  same  form. 
When  the  tooth  has  four  cusps,  this  surface  partakes  of  the  outlines  of  the 
second  molar,  being  surmounted  at  its  morsal  margin  by  two  cusps,  divided 


24        .  OPERATIVE    DENTISTRY. 

by  the  buccal  groove.  When  it  has  five  cusps  it  is  like  the  buccal  surface 
of  the  first  molar,  being  surmounted  at  its  morsal  margin  by  three  cusps, 
which  are  divided  by  the  buccal  and  disto-buccal  grooves. 

The  lingual,  mesial^  and  distal  surfaces  (Figs.  79,  80,  and  81)  correspond 
so  nearly  to  the  same  surfaces  of  the  other  lower  molars  that  no  separate 
description  is  necessary,  except  to  notice  that  the  distal  surface  is  more 
convex,  and  when  the  fifth  cusp  is  present,  often  very  prominent. 

The  morsal  surface  (Fig.  82)  exhibits  the  greatest  variations  from  the 
other  lower  molars. 

In  the  four-cusped  tooth,  which  is  the  more  common  form,  it  is  the 
counterpart  of  the  second  molar,  with  the  exceptions  that  the  distal  cusps 
are  rarely  so  large  and  well  formed  as  the  mesial,  and  the  central  fossa  is 
sometimes  occupied  by  a  central  tubercle. 

In  the  five-cusped  tooth,  it  partakes  of  the  form  of  the  first  molar,  and 
is  frequently  larger  than  the  second.  The  distal  cusp  is  usually  placed 
more  disto-lingually,  the  buccal  surface  is  more  rounded,  and  numerous 
supplemental  grooves  and  ridges  are  often  present. 

The  morsal  surface  is  sometimes  surmounted  by  six,  seven,  or  eight 
cusps,  as  many  supplemental  grooves,  and  one  or  more  supplemental  ridges 
within  the  central  fossa. 

Such  teeth  are  always  very  large,  the  grooves  deeply  fissured,  and  the 
structure  poorly  organized,  predisposing  them  to  early  destruction  from 
caries.  Occasionally  the  inferior  third  molar  is  much  smaller  than  the 
second,  having  a  circumference  of  not  more  than  two-thirds  as  large  as 
this  tooth. 

A  common  feature  of  the  crown  is  its  inclination  towards  a  circular 
form. 

The  cervix  is  similar  in  shape,  in  the  typical  forms,  to  the  second  molar. 

The  roots  are,  in  comparison,  smaller  and  more  rounded  than  in  the  other 
lower  molars.  They  are  generally  divided,  but  have  a  greater  convergence, 
and  in  some  instances  are  fused  together  in  the  form  of  a  single  cone,  but 
in  either  case  they  are  almost  invariably  curved  distally,  sometimes  very 
considerably,  so  that  their  extraction  is  often  a  difficult  operation.  Occa- 
sionally the  tooth  may  have  three  or  more  roots. 

The  pulp-canal  is  sometimes  single,  but  usually  it  is  divided.  The  canals 
are,  as  a  rule,  difficult  to  enter  on  account  of  the  location  of  the  tooth,  the 
generally  small  size  of  the  canals,  and  the  almost  certain  distal  curvature 
of  the  roots. 

The  average  length  of  the  inferior  third  molar  is  0.62  inch  (1.57  centi- 
metres), of  the  crown  0.26  inch  (0.66  centimetre),  and  of  the  root  0.36  inch 
(0.91  centimetre). 

THE   DECIDUOUS   TEETH. 

The  deciduous  teeth  resemble  in  every  way  the  same  class  of  teeth  in  the 
permanent  set,  with  the  exception  of  the  first  molars.  They  are,  however, 
all  much  smaller  than  the  permanent  teeth,  and  are  much  whiter  in  color. 

The  incisors  and  cuspids  of  both  jaws  are  similar  in  form  to  the  teeth 
which  succeed  them.  The  cervix,  however,  is  more  constricted,  and  the 
enamel  ends  more  abruptly.     The  process  of  resorption  of  the  roots  of  the 


Distal  groove 


Disto-lingual  cusii 


Disto-bviccal  cusp 


Fig.  81. — Inferior  rislit  third  molar,  distal  surface.     (Enlarged.) 


Disto-lingual  cusii 


Central  fossa 


Disto-buceal  cusi 


Mesio-lingual  cusp 


Mesial  groove 


Mesial  cusp 


Mesio-1  >nccal  cusp 


Median-buccal  cusp  Buccal  groove 

Fig.  S2. — Inferior  right  third  molar,  morsal  surface.     (Enlarged.) 


CLASSIFICATION   AND    DESCRIPTIVE    ANATOMY    OF    THE    TEETH. 


25 


deciduous  teetli,  whicli  allows  tlieir  crowns  to  fall  away,  begins  in  the  cen- 
tral incisors  at  about  thefoiirth  year,  and  is  completed  at  about  the  seventh. 
In  the  lateral  incisors  this  xDrocess  begins  at  about  the  fifth  year,  and  is 
completed  at  about  the  eighth  ;  while  in  the  cuspids  it  is  delayed  until  the 
ninth  year,  and  completed  at  the  twelfth. 


The  superior  first  deciduous  molars  are  unlike  the  molars  of  tlie 
permanent  set  in  that  the  crown  has  but  three  lobes  or  cusx)S,  mesial,  distal, 
and  lingual,  which  are  divided  by  three  developmental  grooves,  the  mesial, 
distal,  and  huceal.  The  cusps  converge  towards  the  centre  of  the  crown, 
giving  the  morsal  surface  the  appearance  of  being  smaller  than  the  base  of 
the  crown.  The  cervix  is  constricted,  while  the  enamel  ends  so  abrui^tly  at 
the  bucco-cervical  margin  as  to  form  a  prominent  ridge,— the  huceal  ridge. 

Another  distinctive  feature  is  that  the  marginal  ridges,  triangular 
ridges,  and  angles  are  more  acute  than  in  the  i:)ermanent  molars.  Its 
greatest  diameter  is  bucco-liugually. 

The  superior  second  deciduous  molars  are  larger  than  the  first ; 
the  morsal  surface  is  wider,  and  is  surmounted  by  four  cusps,  and  in  other 
ways  the  x)rototyx)e  of  the  superior  second  permanent  molar. 

The  inferior  deciduous  molars  are  similar  in  general  form  and  out- 
line to  the  permanent  molars.  The  first  molar  has  four  cusps  uj^on  its 
morsal  surface,  while  the  second  molar,  unlike  the  second  iDcrmanent 
molar,  has  five  cusps.  The  cusps  and  the  marginal  and  triangular  ridges 
are  more  marked  and  prominent ;  the  central  fossa  is  large  and  deei),  being 
sometimes  divided  by  the  triangular  ridges  forming  two  or  more  fossse  or 
I)its.  The  cervix  is  constricted  and  the  bu  ceo -marginal  ridge  prominent. 
The  mesio-distal  diameter  of  the  crown  is  greater  than  the  bucco-liugual. 

The  roots  of  the  deciduous  molars  differ  from  the  permanent  in  that 
they  are  relatively  thinner  and  longer,  and  are  much  more  spread  or 
divergent  to  accommodate  the  crowns  of  the  succeeding  bicuspids. 

The  imlp-chamher  is  i^rox^ortionately  much  larger  than  in  permanent 
molars,  but  the  root-canals  are  thin  and  narrow,  making  their  treatment 
difficult. 

The  process  of  resorption  in  the  roots  of  the  first  molars  begins  at  about 
the  sixth  year,  and  is  completed  at  tlie  tenth,  while  for  the  second  molars  it 
begins  at  about  the  eighth  year  and  is  completed  at  the  eleventh. 


CHAPTEE  11. 

OEIGIN,  DEYELOPMENT,  AND  MOEPHOLOGY  OF  THE  TEETH. 


Definition. — Morphology  (from  the  Greek  p-opcj)-/]^  form,  and  X6yu<;^  a  dis- 
course). The  science  of  biologic  forms,  including  their  relations,  changes, 
and  analogies ;  the  science  of  the  shape  and  modifications  of  organs  or 
parts  considered  under  the  idea  of  unity  of  plan. 

Anatomists  until  quite  a  recent  period  have  looked  upon  the  teeth  as 
members  of  the  osseous  framework  of  the  body,  but  they  are  now  classified 
as  portions  of  the  dermal  skeleton.  This  change  in  the  classification  was 
brought  about  by  prolonged  study  and  research  into  their  origin  and  de- 
velopment. 

The  invention  of  the  compound  microscope  has  made  it  possible  for  the 
scientist  to  delve  into  the  hidden  mysteries  of  nature  and  reveal  to  the 
world  the  wonders  of  many  of  her  processes  and  the  secrets  of  her  labora- 
tories ;  to  picture  the  wonderfully  minute  elemental  or  embryonic  cells 
from  which  organized  structures  are  formed,  and  the  marvellous  delicacy 
and  precision  with  which  these  are  arranged  in  the  building  of  tissues  and 
organs. 

The  discoveries  made  by  the  microscope  during  the  last  three  or  four 
decades  in  the  morphology  and  the  histology  of  vegetable  and  animal 
tissues,  and  in  pathology  and  bacteriology,  have  been  truly  wonderful,  and 
in  no  department  of  science  have  greater  discoveries  been  made  than  in 
that  department  of  medicine  known  as  dentistry. 

The  researches  of  Hunter,  Bell,  and  Goodsir  marked  the  beginnings  of 
dental  morphology  and  histology,  and  prepared  the  way  for  the  later  inves- 
tigations into  the  evolution  of  the  teeth. 

The  errors  into  which  these  earlier  investigators  fell  were  due  largely  to 
the  non-possession  of  adequate  facilities  for  studying  the  minute  structures 
of  the  embryonic  tissues.  With  the  higher  powers  of  the  microscope  it 
became  possible  to  delve  deeper  into  the  mysteries  of  the  evolution  of  the 
dental  tissues  than  these  old  masters  had  been  permitted  to  do.  The  re- 
sults of  these  investigations  have  proved  conclusively  that  the  enamel- 
organs  had  their  origin  in  the  epithelial  tissues,  and  hence  were  formed 
from  the  same  tissue  elements  as  the  hair,  the  nails,  and  the  epithelial 
lining  of  the  glandular  structures  of  the  skin  and  the  mucous  membrane, 
— namely,  epithelial  cells. 

EVOLUTION   OF   EPITHELIAL   TISSUE. 

In  order  that  the  student  may  approach  the  subject  of  the  evolution  of 
the  teeth  with  a  clear  understanding  of  the  tissue  elements  which  eiiter 
into  their  structure,  it  will  be  advisable  to  present  in  brief  review  the 
morphology  and  the  character  of  epithelial  tissue  in  general. 

In  all  animals  which  are  developed  from  an  ovum  (Fig.  84),  as  soon  as 
impregnation  has  taken  place  and  the  proper  conditions  of  incubation  are 

2o 


Fig.  S4. — Graafian  follicles,  or  ova,  in  various  stages  of  development.     >(  : 


Fig.  86. — Transverse  section  of  embryo  of  cliick,  eighteen,  liours  incubation,  sliowiug  epiblast  and 

hypoblast.     (After  Aby.) 


Fio.  87. — Transverse  section  of  embryo  of  chick,  twenty-four  hours  incubation.    (After  Aby. 


Fio.  88. — Transverse  section  of  embryo  (if  cliick,  tliirly-six  liours  iiirubation.     (After  Aby.) 


Epidermis 


Fig.  89. — Vertical  section  of  human  skin.     >(  ,S7 


Cuticle 


Fig.  90. — Vertical  section  of  skin  of  middle  finger.     )<  50. 


Fig.  91. — Squamous  epithelium  from  buccal  cavity.    A,  squamous  epithelial  cells  ;  B,  salivary  corpiuscles. 

X  162.5.     (V.  A.  Latham). 


Pig.  92. — Longitudinal  sectioiL  of  lip  of  kitten,     v  .SO. 


ORIGIN,  DEVELOPMENT,  AND   MORPHOLOGY   OF   THE   TEETH. 


27 


Division  of  mammal  ovum  (half  diagrammatic). 
1,  the  yolk  divided  into  two 'globules  (cells)  with 
nuclei ;  2,  quadrupled  ;  3,  a  large  number  of  nucle- 
ated cells ;  4,  a,  b,  isolated  cells. 


established, — and  this  is  best  studied  in  the  egg  of  the  bam  fowl, — there 
occurs  a  rapid  proliferation  of  embryonic  cells  in  the  germinal  spot  or 
disk  of  Pander.  This  disk  is  at 
first  composed  of  a  germinal  cell, 
which  by  the  process  of  karyokine- 
sis — indirect  division  or  segmenta- 
tion of  the  cell — produces  a  rapid 
multiplication  of  these  elemental 
cells  (Fig.  85,  1,  2,  3,  4). 

These  embryonic  cells  soon  ar- 
range themselves  into  two  layers, 
known  as  the  epiderm  or  epiblast, 
and  the  hypoderm  or  hypoblast,  the 
epiblast  forming  the  upper  layer 
and  the  hypoblast  the  lower  (Fig. 
86).  Later  a  third  stratum  of  cells 
is  developed  between  the  epiblast 
and  the  hypoblast,  which  is  known 
as  the  mesoderm  or  mesoblast  (Figs. 
87  and  88). 

From  these  three  layers  all  of 
the  tissues  and  the  various  organs 

of  the  body  are  developed.  From  the  epiblast  are  developed  the  various 
layers  of  the  skin  (Fig.  89), — viz.,  the  epidermis,  or  cuticle,  the  derma,  or 
true  skin,  and  the  rete  mucosum,  or  Malpighian  layer, — the  glandular  ap- 
pendages of  the  skin,  the  hair,  the  nails,  and  the  entire  nervous  system. 

From  the  hypoblast  are  developed  the  lining  mucous  membrane  of  the 
alimentary  tract,  of  the  air-passages,  of  the  genital  apparatus,  the  epithe- 
lial linings  of  the  serous  cavities,  the  lining  membrane  of  the  heart,  the 
blood  and  lymphatic  vessels,  and  the  enamel  organs  of  the  teeth.  From 
the  mesoblast  are  developed  the  remaining  portions  of  the  body, — viz.,  the 
bones,  muscles,  blood-vessels,  lymi)hatic  vessels,  connective  tissue,  etc. 

Epithelial  cells  are  common  to  both  the  skin  and  the  mucous  membrane, 
their  peculiar  characteristics  depending  upon  their  location  and  their  par- 
ticular function,  as,  for  instance,  in  the  skin  (Fig.  90)  they  may  form  the 
cuticle,  or  horny  layer,  when  they  are  squamous  or  scaly  in  shape  (Fig.  91)  ; 
if  forming  the  lining  of  a  tubule  of  a  sweat-gland  they  are  cuboidal ;  when 
entering  into  the  formation  of  the  hair-sheath  they  are  columnar  (Fig.  92), 
while  in  the  shaft  of  the  hair  they  become  squamous,  the  cells  being  over- 
laid like  the  scales  of  a  fish  (Fig.  93). 

In  the  development  of  the  nail-plate  they  are  also  columnar,  but  rapidly 
become  squamous  and  cornified. 

In  the  mucous  membrane  of  the  mouth  the  most  superficial  layer  of 
epithelial  cells  is  of  the  squamous  variety,  while  beneath  this  lies  a  layer 
of  spinous  or  furrowed  cells,  the  spines  of  which  interlock  with  neighboring 
cells,  and  by  this  means  are  held  together.  Immediately  beneath  this 
stratum  is  another,  the  Malpighian  layer,  made  up  of  small,  soft,  roundish 
cells,  sometimes  oval  in  form,  and  arranged  in  a  regular  order,  standing 


28 


OPERATIVE   DENTISTRY. 


Section  of  jaw  of  rab- 
bit embryo,  sliowing 
dental  ridge  cut  across  : 
ec,  oral  epithelium ;  e, 
epithelial  outgrowth  cor- 
responding to  future 
enamel  organ  ;  m,  meso- 
blastic  tissue. 


upright  upon  the  basement  membrane  (Figs.  94  and  95).  Other  peculiar 
epithelial  cells  found  in  the  mucous  membrane  of  the  mouth  are  known 
as  the  ciliated  columnar  cell  (Fig.  96)  and  the  goMet-cell  (Fig.  97),  the 
functions  of  which  with  the  mucous  gland  are  to  secrete  mucus.  The 
mucous  glands  are  also  lined  with  epithelial  cells,  usually  in  a  single 
layer,  and  cuboidal  or  columnar  in  form. 

From  the  deeper  strata  of  epithelial  cells,  the  Malpighian  layer  of  the 
mucous  membrane,  the  enamel  organs  of  the  teeth  are 
formed. 

It  is  interesting  to  note  the  analogy  in  the  mor- 
X^hology  of  the  teeth  and  the  hair. 

By  comparing  Figs.  98  and  99,  it  will  be  seen  that 
the  first  rudiments  of  the  tooth-follicle  and  the  hair- 
follicle  have  their  origin  in  the  lower  layer  of  epithe- 
lial cells, — MaliDighian  layer, — which  dips  down  into 
the  embryonic  tissue  of  the  mesoblast.  The  likeness 
can  be  still  further  traced  in  the  formation  of  the  pa- 
pillae and  the  invagination  of  the  flask-like  bud,  (See 
Figs.  100  and  101.) 

Until    1837,   when    Goodsir  published   his  theory 
of  the  evolution  of  the  teeth,  there  had  been  no  dis- 
tinct,   formulated  teaching  upon  this  subject.     This 
theory  was  at  once  adopted  by  anatomists  generally, 
and  was  incorporated  into  all  standard  works  on  anatomy  and  histology. 

Huxley,  Kolliker,  Waldeyer,  Kollman,  and  Guillot  were  the  first  to 
cast  doubt  ux3on  the  correctness  of  the  theory  of  Goodsir.     In  1860  there 

appeared  a  treatise  by  Eobin  and  Magitot, 
entitled  ''The  Genesis  and  Development 
of  the  Dental  Follicle  to  the  EruiDtion  of 
the  Teeth  ;"  this  xd roved  the  Goodsir  theory 
to  be  based  upon  errors  due  to  methods  of 
manijDulation.  It  also  contained  serious 
errors  in  the  order  of  the  genesis  of  the 
dental  tissues,  the  most  conspicuous  of 
which  was  the  statement  that  the  dentin 

First  rudiments  of  a  hair  from  the  bulb  WaS  the  first  part  of  the  follicle  tO 
human  embryo  of  sixteen  weeks,  a,  b,  y.^,  formed 
layers  of  cuticle  ;  m,  m,  cells  of  the  rudi- 
mentary hair ;  i,  hyaline  envelope.  It  was  not,  however,  until  the  appear- 
ance of  the  treatise  ' '  The  Origin  and  For- 
mation of  the  Dental  Follicle,"  by  Legros  and  Magitot,  that  the  Goodsir 
theory  was  fully  overthrown. 

The  teaching  of  these  authors  has  stood  the  test  of  more  than  thirty 
years  of  investigation  without  a  single  imx)ortant  statement  having  been 
successfully  controverted.  Many  facts,  however,  in  relation  to  the  develop- 
ment of  the  individual  dental  tissues  have  since  been  discovered  and  be- 
come a  part  of  dental  histology.  We  may,  therefore,  feel  fairly  certain 
that  in  so  far  as  the  evolution  of  the  dental  follicle  is  concerned,  we  are 
resting  upon  a  solid,  scientific  foundation. 


Fig.  99. 


Fig.  93. — Transverse  section  of  hairs  of  scalp.     ;<  fiO. 


Fig.  P4. — Epithelial  layer  of  tiie  mncons  membrane.     A,  squamous  cells  ;  JJ,  columnar  ttells. 

(R.  R.  Andrews.) 


Fig.  95. — Columnar  epithelial  cells.     •,  <i70. 


Fig.  9ti. — Ciliated  columnar  epithelial  cells.     >(  670. 


Columnar : 

epithelial  :■ 

cells' 


Goblet- 
•  cells 


Fig.  97.— Goblet-cells.     X  500. 


Invaginatin^ 
enamel  organ  j 

Dentin  papilla; 


Enamel-organ 
before  invagi- 
nation 


yiG.  100. — Lower  jaw  of  human  embryo,  ninth  to  tenth  week.     >C  HO. 


Shaft  of 
hair 


Invagi  '     ^  ^i 
nated  bulb      '  ^, 

Papilli  ' 


a 


ii 

~ 

i< 

^ 

' 

Fig..  101. — Vertit-al  Hectinn  of  the  skin,  sljuwintr  hnllicins  ends  of  two  hairs.     :<  ^^. 


Develop-  ^'    ^^ 
ingdecid-F 
iious  tooth  I 


•pr^--^"^^ 


Upper  Jaw 


^ecMiiidary 
■  ■jiithelial 

roni 


Secondary 
I'liithelial 
cord 

T.dwer  jaw 


>•>  ' 


Fig.  103. — Vertical  secjtion  through  head  of  human  foetus,  showing  completed  rudimentary  jaws,  etc.     X  80. 


Develop- 
ing tooth 


Develop- 
ing bone 


Fig.  104. — Lower  jaw  of  human  fcetus,  showing  Meckel's  cartilage.     ;<  80. 


OEIGIlSr,  DEVELOPMENT,  AND    MORPHOLOGY    OF    THE   TEETH.  29 

Before  proceeding  to  a  study  of  tlie  accepted  theory  of  the  evolution 
of  the  teeth  let  us  briefly  review  the  theory  of  Goodsir. 

Goodsir  stated  that  at  a  very  early  period  of  foetal  existence  a  depres- 
sion or  groove,  which  he  termed  the  primitive  dental  groove,  was  formed  in 
the  mucous  membrane  along  the  entire  circumference  of  the  alveolar  border 
of  both  jaws ;  that  from  the  bottom  of  this  groove  in  each  jaw  papillae 
arose,  ten  in  number,  isolated  and  uncovered,  which  represented  the  future 
deciduous  teeth  ;  that  later  these  papillae  became  closed  in  by  the  approach- 
ing of  the  walls  of  the  groove  and  by  the  formation  of  separate  septa 
between  the  papillae,  thus  enclosing  each  of  them  in  an  independent 
follicle. 

The  permanent  teeth,  except  the  molars,  were  formed  in  like  manner, 
within  what  he  termed  the  secondary  dental  groove,  which  he  located  behind 
the  primitive  dental  groove,  and  formed  from  the  inner  or  lingual  lip  of 
the  primitive  dental  groove.  In  this  secondary  dental  groove  were  formed 
the  ten  anterior  permanent  teeth, — the  teeth  of  replacement, — while  the  first 
permanent  molar  was  evolved  within  the  posterior  portion  of  the  primitive 
dental  groove,  which  had  remained  open  for  this  purpose  ;  and  the  second 
permanent  molar  is  developed  from  a  papilla  given  off  from  the  first  perma- 
nent molar  at  the  seventh  or  eighth  month  after  birth,  and  the  third  molar 
from  a  papilla  given  off  from  the  second  permanent  molar  at  a  still  later 
period  in  childhood. 

A  study  of  the  origin  and  development  of  the  teeth  should  take  into 
account,  also,  the  evolution  of  the  jaws,  which  may  be  briefly  outlined  as 
follows  : 

THE   EVOLUTION   OE   THE   JAWS. 

In  the  human  subject  the  first  evidence  of  the  formation  of  the  superior 
maxilla  is  seen  very  early  in  the  life  of  the  embryo, — viz.,  at  about  the 
eighteenth  day  after  conception,  by  the  develop-  ^ 

ment  of  four  tiny  buds,  tubercles,  or  processes  ^_"^^_  "" 

near  the  central  portion  of  that  surface  of  the  yg^^^m^^^^^ 

rudimentary  head  which  is  destined  to  form  the  ^p         B       ^^^ 

face  (Fig.  102),  and  which  are  denominated  the  ^^        ^^^      ;^BL 

superior  or  frontal  processes  or  tiibercles,  and  the         ^^''      '^^^'^j^^^ 

lateral,  oblique,  or  maxillary  processes  or  tubercles.  ^^  .^WW-^^'^P''^^'  ^ 

The  superior  processes  elongate  downward,  ^  ^p     wCT^m  ""iSf"  ^ 
and   at   the   same   time   api^roach   each   other         ^'  41^^^*^^^  ^ 
towards  the  median  line,   where  they  finally         ^^^^^P^H^^^ 
coalesce,  at  about  the  twenty-fifth  day,  to  form         ^^^htjiTiw^^^^ 
the  intermaxillary  bones  and  the  central  por-         f^d^  Hjj^ 

tion  of  the  upper  ll]).     The  lateral  processes         W^lf  ^l|l 

likewise    elongate,   and   apj) roach   each    other         ''  | 

towards  the  median  line,  where  they  finally,  at        Head  of  human  embryo.  (His.) 

about  the  twenty-eighth  day,  meet  the  superior  ^'  ^'  ^^p^^^^^  processes;  b,  B,oh- 

•J       ^  "^ '  ^  lique  processes. 

processes,  and  unite  vfith  them,  thus  forming 

the  lateral  halves  of  the  rudimentary  superior  maxillary  bone,  palate 
bones,  the  cheeks,  the  lateral  portions  of  the  upper  lip,  and  the  velum 
palati  (Fig.  103). 


30  OPERATIVE   DENTISTRY. 

Coincidently  with  the  development  of  the  superior  maxillae,  a  simi- 
lar process  of  development  has  been  going  on  for  the  formation  of  the 
inferior  maxilla.  At  about  the  eighteenth  day  two  similar  tiny  buds  or 
processes  appear  just  beneath  the  lateral  processes,  and  grow  rapidly  to- 
wards the  median  line,  where  they  unite  at  about  the  twenty-eighth  day, 
and  complete  the  arch  of  the  lower  jaw.  Very  soon  afterwards  a  little 
cartilaginous  hand  makes  its  appearance  within  the  central  portion  of  the 
rudimentary  jaw,  MecJceVs  cartilage  (Fig.  104).  This  cartilaginous  band 
is  composed  of  two  parts,  which  arise  from  the  mallei  of  the  ears,  and 
extend  forward  until  they  unite  at  the  mental  symphysis.  Meckel's  car- 
tilage gives  form  and  stability  to  the  inferior  maxillary  arch  until  ossifica- 
tion takes  place,  when  it  disappears  by  absorption  or  becomes  calcified, 
forming  a  part  of  the  maxillary  bone. 

EVOLUTION   OF   THE   TEETH. 

The  earliest  evidences  of  the  evolution  of  the  teeth  are  to  be  found  at 
about  the  seventh  week  of  intrauterine  life,  in  the  shape  of  a  depression  or 

involution  of  the  Malpighiau  stratum  of 
the  epithelial  cells  upon  the  alveolar  border 
of  the  rudimentary  jaws  (Fig.  105),  forming 
what  is  known  as  the  epithelial  band.  This 
band  is  composed  of  the  same  cell  elements 
that  are  found  in  the  epithelial  tissue  of  the 
"  ^^t'^'f  «^^  ^  oral  mucous  membrane,  the  band  or  groove 

Involution  of  the  Ma'ipighian  stra-  being  bouudcd  by  a  layer  of  columnar  or 
turn.  Section  of  jaw  of  rabbit  embryo,     prismatic  cclls,    which   include  a  mass  of 

showing  thickening  of  epiblastie  epi-  t    -,      -i      -,  tjt         ti       ,-,  -,-,       ■       ji 

theiium  (ec)  from  which  the  Maipigh-    polyhedral  nucleated  cells,  the  cells  m  the 
ian  stratum  (e)  begins  its  growth  into     centre   oftcu  being  of  the  denticulated  or 

the  mesoblast  (m)  to  form  the  epithe-  .  .    , 

liaiband.   (Piersoi.)  spinous  Variety. 

This  band  or  groove,  as  it  descends  into 
the  embryonic  tissue  of  the  jaw,  curves  slightly  inward,  and  is  filled  and 
heaped  u]j  with  flattened  epithelial  cells,  making  what  is  known  as  the 
dental  ridge,  the  maxillary  rampart  Of  Kdlliker,  Waldeyer,  and  Kollman. 
The  next  step  in  the  evolution  of  the  dental  follicle  occurs  between  the 
seventh  and  eighth  weeks,  when  the  epithelial  band  or  groove  sends  off  a 
thin  lamina  or  process  upon  its  lingual  aspect  in  each  jaw, — the  epithelial 
lamina, — which  occupies  a  horizontal  position  to  the  epithelial  band.  Buds 
or  processes  also  appear  upon  the  extremity  or  edge  of  the  lamina, — the 
primitive  epithelial  cord, — which  elongates  and  dips  down  into  the  embryonic 
tissue  of  the  jaw.  At  about  the  eighth  week  the  enamel-organs  are  clearly 
defined  as  club-shaped  enlargements  upon  the  extremities  of  the  primitive 
epithelial  cords  (Fig.  106),  and  the  dentin  papillce,  or  dentin  bulbs,  can  be 
discovered  as  opaque  points  directly  beneath  the  enamel-organ  in  the  meso- 
blastic  tissue. 

Fig.  107  represents  the  epithelial  cord  in  the  i)receding  illustration, 
highly  magnified,  and  Fig.  108  shows  the  same  in  cross-section. 

The  process  of  evolution  advances  synchronously  at  this  period  in  all 
the  follicles  of  the  deciduous  teeth. 


Ym.  ion. — Lower  jaw  of  human  embryo,  seventh  to  eighth  week.     X  75. 


K])ithelial  lamina 


Polyhedral,  ui 

flatten  I'll 

epithelial  cclN 


I  'l\ib-shaped  en- 
largement of  the 
ipithelial  cord 


Fig.  107. — "Vertical  section  of  epithelial  cord,  or  primitive  enamel-organ.     X  300. 


-■T^t     -f^x,  iJa 


iiiS' 


Epithelial 
cord 


V.  r-ftL^ 


Fig.  108. — Cross-section  of  epithelial  cord.     ~<  .SOO. 


Fig.  109. — Primitive  epithelial  cord,  showing  a  jieculiar  turning  of  the  end.     X  45. 


■In.v>agwiation,  of  enamol-organ 


Dentin 
papillffi 


Invagination  of  enamel-organ 
Fig.  110. — Vertical  section  through  lower  jaw  of  embryo  field  nionse. 


Primary  epithelial  conl 


Dentin  papillas 


Bud  to  form  the 
secondary  epi- 
thelial cord 

Enamel-organ 


Fig.  111. — Evolution  of  dental  follicle  at  about  the  ninth  week,  showing  invagination  of  enamel-organ. 

X  70. 


odontoblasts 


iJentin 
jiapi  11:13 


Sat:  wail 


Fill.  11'2. — Developing  human  cuspid. 


Enamel-organ 


Membrana  eboris 


Dentin  papilla; 


Constriction  at 
base  of  papillae 


Blood-vessel 


Blood-vessi'l 


External  epithe- 
lium of  enamel- 
organ 


Membrana  eboris 


Internal  epithe- 
'ium  of  enamel- 
organ 


Blood-vessel 


Sac  of  follicle 


Forming  Bone 


Fiii.  113. — Follicle  of  Innnan  molar  at  about  the  eleventh  week.       ;  ."iO. 


OEIGIN^  DEVELOPMENT,  AND    MORPHOLOGY   OF    THE    TEETH.  31 

The  club-like  enamel-organs  now  rapidly  enlarge  and  become  pear- 
shaped  in  form.  In  Fig.  109  a  peculiar  hook-shaped  termination  is  noticed, 
which  is  doubtless  a  malformation,  as  no  reference  is  made  to  it  by  other 
observers,  and  has  not  been  seen  before  by  the  writer.  This  pear-shaped 
enlargement  is  due  to  a  rapid  proliferation  of  the  polyhedral  epithelial 
cells  contained  within  them,  and  of  the  columnar  cells  which  form  the 
outer  boundary.  The  enamel- organ  has  now  attained  its  full  size,  and 
occupies  a  position  within  the  deeper  structures  of  the  jaw,  and  slightly 
inclined  towards  its  lingual  aspect. 

The  next  important  feature  in  the  development  qf  the  follicle  is  the  in- 
vagination of  the  enamel- organs,  as  shown  in  Fig.  110.  This  change  occurs 
simultaneously  with  the  appearance  and  growth  of  the  dentin  papillae. 
Immediately  beneatli  each  enamel-organ  is  developed  from  the  mesoblastic 
tissue  a  cone-shaped  bulb  or  papilla  similar  to  the  papillae  found  in  the 
gums  and  mucous  membrane  of  the  mouth. 

The  dentin  parpillm  (Fig.  Ill)  in  its  earliest  stage  of  development  is  com^ 
posed  simply  of  embryoplastic  neucleated  cells,  but  soon  afterwards  it  con- 
tains fusiform  and  stellate  cells  ;  it  also  contains  a  vascular  loop,  but  Eobin 
and  Magitot  were  unable  to  discover  in  it  any  nerve-fibres. 

As  soon  as  this  new  organ  has  assumed  a  conical  form,  which  occurs  at 
about  the  ninth  week,  there  arises  from  its  base,  as  seen  in  microscopic 
sections,  two  opaque  i^rocesses,  which  are  the  first  traces  of  the  wall  or  sac 
of  the  future  follicle.  These  processes,  which  really  surround  the  base  of 
the  papillae  like  a  collar  (Fig.  112),  elongate  as  the  bulb  increases  in  size 
and  length,  converging  towards  each  other  until  they  finally  embrace  the 
bulb  and  enamel-organ  in  their  entirety. 

As  the  dentin  bulb  enlarges  and  elongates  it  comes  in  contact  with  the 
inferior  portion  or  lower  plane  of  the  enamel-organ,  which  is  gradually 
carried  upward  until  it  is  completely  invaginated,  thus  forming  a  double- 
walled  caj)  or  hood  over  the  dentin  jjapilla. 

It  is  interesting  to  note  the  fact  that  during  the  growth  of  the  dentin 
papilla  and  the  invagination  of  the  enamel-organ  a  reciprocal  adaptation 
of  these  organs  takes  place  from  the  commencement  of  the  process,  and 
continues  throughout  all  subsequent  phases,  the  enamel-organ  at  all 
times  covering  the  dentin  bulb,  and  being  adapted  to  its  varying  con- 
tours (Fig.  113) .  At  no  time,  however,  during  the  process  of  development 
do  the  tissues  of  these  two  organs  become  united. 

Sudduth  confirms  the  teaching  of  Legros  and  Magitot,  and  says  there 
is  no  union  between  the  enamel-organ  and  the  papilla,  nor  have  vessels  or 
nerve-fibres  ever  been  demonstrated  as  j)assing  from  one  to  the  other. 

Bodecker  takes  an  opposite  view,  and  states  that  when  the  enamel- 
organ  is  detached  from  the  dentin  papilla,  as  frequently  occurs  in  making 
sections,  there  appears  upon  the  outer  surface  a  delicate  fringe,  which  he 
believes  to  be  the  true  connection  between  the  enamel-organ  and  the 
papilla. 

Fig.  114  is  here  introduced  to  show  the  stage  of  general  development  of 
the  human  embryo  at  the  eleventh  or  twelfth  week. 

At  about  the  eleventh  week  a  notable  change  has  taken  place  in  the 


32  OPERATIVE    DENTISTRY. 

shape  of  tlie  dentin  papillae,  wliich  have  now  assumed  the  forms  of  the 
crowns  of  the  teeth  which  they  represent.  At  this  time,  also,  a  narrowing 
or  constriction  takes  place  at  the  base  of  the  papilla,  forming  a  kind  of 
neck  at  the  free  border  of  the  enamel-organ  (Fig.  113). 

In  examining  vertical  sections  of  the  dentin  bulb  at  this  period, 
the  existence  of  a  thin,  clear,  transparent  zone  of  amorphous  material 
upon  the  periphery  of  the  organ  is  discovered.  This  amorphous  material 
is  destitute  of  anatomic  elements,  somewhat  more  transparent  and  denser 
than  the  subjacent  tissue  of  the  dentin  papilla,  and  capable  of  being  de- 
tached from  the  surface  of  the  latter.  This  condition  led  Raschkow  and 
others  to  suppose  the  papilla  to  be  invested  with  a  distinct  membrane,  the 
memhrana  prcBformativa  of  Easchkow,  and  the  membrana  eboris  of  later 
writers.  This  zone  of  amorphous  material  lies  between  the  enamel-organ 
and  the  dentin  x)apilla  (Fig.  115). 

Black,  in  siDcaking  of  this  layer,  says,  ^'  Just  before  the  calcification, 
and  even  before  the  odontoblasts  make  their  appearance,  the  ameloblasts 
and  the  tissues  of  the  pulp  are  separated  by  a  well-marked  double  pellucid 
layer,  which  in  section  appears  as  a  double  band."  Andrews  says,  ''If 
the  tissue  has  been  carefully  prepared,  minute  glistening  bodies — calco- 
sjpherites — are  seen  under  the  higher  powers  of  the  microscope,  in  the  den- 
tin bulb  and  within  this  layer,  which  indicates  the  near  approach  of  the 
process  of  calcification.  The  first  layer  of  odontoblasts  is  formed  within 
the  transparent  amorxDhous  material,  and  although  the  ameloblasts  make 
their  appearance  first,  calcification  does  not  take  place  in  them  until  after 
the  odontoblasts  have  formed  a  caj)  of  calcified  dentin  upon  which  the 
enamel-rods  are  to  rest  (Fig.  116). 

The  character  of  the  cells  contained  within  the  body  of  the  enamel- 
organ  have  also  become  greatly  changed,  and  appear  as  stellate  bodies 
within  a  reticular  structure  (Fig.  117). 

The  next  important  change  in  the  process  of  development  is  seen  at 
about  the  sixteenth  week,  in  the  form  of  a  tiny  but  well-defined  cap  of 
calcified  dentin  at  the  tips  of  the  incisors  and  cuspids,  and  about  a  week 
later  in  the  molars  (Fig.  118).  Calcification  has  not  yet  begun  in  the  amel- 
oblasts, although  they  are  fully  developed  and  well  defined.  The  primi- 
tive epithelial  cord  is  still  attached  to  the  enamel- organ,  and  the  sac  is  not 
yet  closed. 

Another  important  change  also  takes  place  at  this  time, — viz.,  the 
budding  of  all  the  primitive  cords  upon  their  lingual  aspect  to  furnish  the 
enamel-organs  for  the  ten  anterior  permanent  teeth  in  each  jaw.  The  buds 
rapidly  assume  a  pear-shaped  form,  as  shown  in  Fig.  119,  followed  by  the 
appearance  of  the  dentin  papillae  and  invagination  of  the  enamel-organs 
shown  in  Fig.  120. 

Black  believes  the  epithelial  cords  of  the  permanent  follicles  often 
spring  directly  from  the  Malpighian  layer  of  the  epithelial  band  (Fig.  121), 
instead  of  from  the  primitive  epithelial  cords,  as  taught  by  Legros  and 
Magitot. 

At  the  eighteenth  or  nineteenth  week  the  sacs  of  the  primitive  dental 
follicles  are  closed,  and  the  follicles  separated  from  their  epithelial  cords 


Fig.  114. — Human  embryo  at  eleven  to  twelve  weeks  after  conception. 


• 

'  •■  '.  '7' 

' 

- 

- 

stellate 
reticulum 

•    - 

' 

,  ^ 

• 

- 

Amelo- 

blasts 

_ 

- 

Calco- 
spherites 

-- 

^i«Kat_: 

stratum 

%^)-^.  .- 

interme- 
dium 

Dentin 
papillae 

-       . 

~ 

First  lay- 
(!-(  of 
odonto- 
blasts 

( 'apillary 
blood- 
\  ossel 

Capillary 
blood- 
vessel 

- 

i» 

.f.f 

'i 

Fig.  115. — Vertical  section  of  human  molar  at  junction  of  enamel-organ  with  dentin  papilte,  showing  earlj'  stage  of 
cell  differentiation  and  zone  of  amorphous  material.     (V.  A.  Latham.)     X  300. 


Embryonic  connective  tissue 

External  epithelium  of  enamel-organ 


Stellate  reticulum 


Stratum  intermedium 

Ameloblast^  "^i 
Calcified  dentin'  _  _      — »,,     „ 

Dentin  papill^i^  -      -     ^^^ 


Forming  ameloblasts 
'( )dontoblasts 

Fig.  116. — Vertical  section  of  incisor  of  human  tcetus  (partly  diagrammatic). 


\  '^^.  formed 
■y  \  '^fe.  enamel 


Fig.  117. — Oblique  section  of  a  dental  follicle,  showing  stellate  reticulum  of  the  enamel-organ,     x  83. 


Enamel 

Enamel-organ 
Uncalcified  cusp 


lieiitin 


3^K4  ^  ji  Dentin  j>aplll8e 


Forming  bone 


Fig.  118.— Vertical  section  of  human  molar,  showing  early  stage  of  calcification  of  dentin  and  enamel.    X  90. 


1  inthelial  cells 


Budding  of  the 

primitive  ejn 

thelial  cord 


Primitive 
epithelial  cord 


Enamel-organ 
Dentin  papillae 


Fig.  119. — Vertical  tsection  of  cuspid  of  human  f  i  tus   showing  tlic  budding  of  the  primitive  epithelial 

cord.     X  70. 


Enamel-organ, 
permanent  tooth 

Dentin  papillae 


Follicle  of  deciduous  tooth 


Fig.  120. — Vertical  section  of  human  fcetal  maxilla,  showing  the  deciduous  follicle  and  pear-shaped  enlarge- 
ment and  commencing  invagination  of  the  enamel-organ  of  the  permanent  cuspid.    X  70. 


Dentin 
papillae 


Enamel- 
organ 


Fig.  121. — Vertical  section  of  incisor  tooth,  human  embryo.    Superior  maxilla.     (V.  A.  Latham.)     x  50. 


Forming 
bone 


Fig.  1'22. — Section  of  human  developing  tooth,  showing  the  follicle  closed  and  the  primary  epithelial  cord  severed 

from  its  enamel-organ. 


Fig.  123. — Vertical  section  of  dental  follicle  of  cat,  showing  the  follicle  closed,     x  9. 


CHAPTEE   III. 

HISTOLOGY   OF   THE   DENTAL   TISSUES. 

Calcification.— In  the  preceding  chax^ter  the  process  of  development 
of  the  dental  organs  was  studied  to  the  stage  of  calcification  of  the  dentin 
and  enamel.  It  was  then  noticed  that  although  the  enamel-organ  was  the 
first  to  be  formed,  and  that  a  layer  of  specialized  columnar  epithelial  cells, 
the  ameloMasts,  were  arranged  in  a  definite  order  resting  upon  the  coronal 
surface  of  the  dentinal  papilla  or  dentin  germ  (Fig.  126),  apparently  ready 
for  the  process  of  calcification  ;  it  is  not  until  later  that  the  deposition  of 
lime  salts  really  begins  for  the  formation  of  the  enamel.  The  formation 
of  the  dentin  begins  first  by  the  development  of  a  layer  of  specialized 
connective-tissue  cells,  the  odontoblasts,  covering  the  dentin  germ  -,  and 
these  immediately  begin  the  process  of  building  the  first  tiny  cap  of  den- 
tin u]3on  each  of  the  lobes  or  centres  of  calcification  by  the  deposition  of 
lime- salts. 

The  odontoblastic  cells,  which  are  clearly  defined,  are  somewhat  broader 
than  the  ameloblasts,  which  are  situated  immediately  above  them,  and  are 
arranged  in  a  single  layer.  They  are  at  this  stage  ovoid  in  form,  and  are 
apparently  embedded  in  a  transparent  and  structureless  gelatinous  sub- 
stance, in  which  small  globular  masses — calcospherites — are  already 
forming. 

The  function  of  the  odontoblasts  is  to  superintend  the  process  of  calci- 
fication of  the  dentin  by  the  deposition  of  calcific  material,  layer  within 
layer,  upon  the  coronal  surface  of  the  dentin  germ,  which  by  this  pro- 
cess constantly  decreases  in  size  until  the  limit  of  nature  is  reached. 

The  function  of  the  ameloblast  is  also  that  of  superintending  the  laying 
down  of  the  lime -salts  which  are  to  form  almost  the  entire  bulk  of  this 
tissue. 

Definition. — The  term  calcification  comes  from  the  Latin,  calx,  lime, 
and  fiere^  to  become, — to  become  lime  j  hence  the  term  is  used  to  express 
the  physiologic  process  by  which  a  deposition  of  calcium  salts,  or  other 
insoluble  crystalline  matter,  is  laid  down  within  an  especially  prepared 
matrix,  as  in  the  formation  of  bone,  cementum,  dentin,  and  enamel ;  or  a 
pathologic  deposition  of  calcareous  materials  within  tissues  where  they  do 
not  normally  belong,  as  in  the  calcification  of  the  arteries,  inorganic 
deposits  within  serous  membranes ;  the  calcification  of  tubercular 
deposits,  etc. 

By  the  physiologic  process  of  calcification  various  tissues  are  formed 
or  built  up, — by  the  aid  of  especially  endowed  cells, — like  bone,  cementum, 
dentin,  and  enamel.     The  exact  modus  operandi  by  which  this  process  is 
accomplished  has  not  been  fully  established. 
34 


Dentin 
papillae 


^-Mi^^M 


Tig.  126. — Section  of  dental  follicle,  showing  first  layers  of  ameloblasts  an.l  mlouiolilasts.     ;<  1000. 


*^ 


.'**». 


-§^ 

<T^ 

.^^- 


x^ 


■j^, 


^x*- 


.   ,-^^         .-v'^-  "ov 


.v^.\,^^?^^     ^^" 


V.    v — ■ 


V-  -^\^      ^' 


■^     '^^    «T> ' 


Fig.  127. — Section  of  human  femur,  six  mouths'  fiulus,  showing  osteoblasts.     X  109. 


# 


1-"IG.  1:2S.— Forming  dentin,  showing  odontoblasts.     (V.  A.  Latham.)     X  1000. 


J^- 


Fig.  129.— Enamel-cells,  with  nuclei.     (R.  R.  Andrews.) 


HISTOLOGY    OF    THE    DENTAL    TISSUES.  35 

That  tliese  especially  endowed  cells,  osteoblasts,  or  bone-builders  (Fig. 
127),  cementohlasts,  or  cement-builders,  odontoUasts,  or  dentin-builders  (Fig. 
128),  and  amelohlasts,  or  enamel-builders  (Fig.  129),  are  tlie  active  agents 
in  the  construction  of  tliese  tissues  is  a  generally  conceded  fact. 

The  term  used  to  express  calcification  of  the  bone  is  ossification  ;  in  the 
calcification  of  cementum,  cementification ;  in  the  calcification  of  dentin, 
dentinification  ;  and  in  the  calcification  of  enamel,  amelification.  The  process 
in  the  first  three  of  these  is  substantially  the  same. 

There  are  two  methods  by  which  a  calcified  tissue  may  be  formed, — one 
by  the  deposition  of  calcium  salts  within  the  substance  of  a  formative 
organ,  thus  converting  it  into  a  calcified  structure  5  and  the  other  by  a 
formative  organ  excreting  from  its  surface  both  organic  and  inorganic 
constituents.  The  former  method  is  the  process  by  which  bone,  cementum, 
and  dentin  are  formed  ;  while  the  latter  is  the  process  by  which  the  shells 
of  many  mollusks  are  developed,  and  by  most  histologists  thought  to  be 
the  method  by  which  enamel  is  built  up. 

The  calcium  and  other  salts  necessary  for  the  calcification  of  these  tis- 
sues are  held  in  solution  or  in  minute  particles,  so  small  as  to  be  almost 
beyond  the  reach  of  demonstration  by  the  highest  powers  of  the  micro- 
scope, in  the  gelatinous  or  protoplasmic  fluid  in  which  these  specialized 
cells  are  embedded.  It  is  from  this  fluid  or  semi-fluid  medium,  the  inter- 
cellular substance,  charged  with  these  salts,  that  the  cells  derive  the  neces- 
sary pabulum  for  their  nourishment  and  for  the  performance  of  their  func- 
tions. The  supply  of  nourishment  is  derived  and  maintained  by  the 
abundant  vascular  net-work  of  the  neighborhood. 

Eainey  discovered,  and  Professor  Harting  and  Dr.  Ord  further  eluci- 
dated the  fact,  that  the  calcium  salts  in  the  presence  of  albuminoid  sub- 
stances are  changed  chemically,  uniting  with  the  organic  compounds  to 
form  small  globular  bodies  which  were  afterwards  called  calcosplierites. 
These  bodies  are  always  present  in  the  intercellular  substance  just  before 
and  during  the  process  of  calcification. 

•  Eainey  found  in  exj)erimenting  with  the  calcium  salts  that  if  calcium 
carbonate  be  slowly  formed  in  a  thick  solution  of  mucilage  or  albumin,  it 
resulted  in  the  formation  of  tiny  globules,  laminated  in  structure,  from  the 
centre  outward  ;  these  globules  when  in  contact  coalesced  to  form  single 
laminge  in  larger  masses. 

In  the  laminated  structure  of  the  larger  masses,  formed  by  the  coales- 
cence of  the  tiny  globules  into  single  laminae  one  upon  another,  Eainey 
claimed  to  find  the  explanation  of  the  development  of  shells,  bones,  and 
teeth.  A  precipitate  of  calcium  carbonate  alone  in  gelatin  was  at  first  mem- 
branous, but  ra]3idly  passed  into  the  globular  and  crystalline  forms,  while 
a  j)recipitate  of  calcium  i3hosj)hate  alone  became  at  once  crystalline,  with- 
out passing  through  any  colloid  stage,  but  a  precipitate  of  the  bicarbonates 
and  phosphates  retained  for  an  indefinite  period  the  colloid  form.  This  is 
interesting  from  the  fact  that  in  calcified  tissues  like  bone,  dentin,  and 
enamel,  the  carbonates  and  phosphates  are  invariably  found  associated 
together. 

Professor  Harting  discovered  that  the  calcospherite  is  composed  of  a 


36  OPERATIVE    DENTISTRY. 

"profoundly  modified  albumin,"  which  he  termed  calcoglobulin,  and  in 
which  the  calcium  salts  are  held  in  some  form  of  chemical  combination. 
The  calcoglobulin,  which  is  the  matrix  of  the  calcospherite,  is  exceedingly 
resistant  to  the  action  of  acids,  alkalies,  and  boiling  water,  and  is  callable 
of  maintaining  its  form  and  structure  even  after  the  greater  portion  of  the 
calcium  has  been  removed. 

Tomes,  in  commenting  upon  the  character  of  calcoglobulin,  says,  "  It 
is  a  very  suggestive  fact  that  in  the  investigation  of  calcification  we  con- 
stantly meet  with  structures  remarkable  for  their  indestructibility  ;  for 
example,  if  we  destroy  the  dentin  by  the  action  of  very  strong  acids  or 
by  variously  contrived  processes  of  decalcification,  putrefaction,  etc.,  there 
remains  behind  a  tangled  mass  of  tubes  (Fig.  130),  the  '^dentinal  sheaths" 
of  ]^eumaun,  which  are  really  the  immediate  walls  of  the  dentinal  tubes. 

Or  if  bone  be  disintegrated  by  certain  methods,  there  remain  behind 
large  tubes,  found  to  be  the  linings  of  the  Haversian  canals  (Kdlliker), 
and  small  rounded  bodies  recognizable  as  isolated  lacunae  f  and  in  the  cuti- 
cula  dentis — Nasmyth's  membrane — we  have  another  excellent  example  of 
this  peculiarly  indestructible  tissue. 

In  x^oint  of  fact,  as  will  be  better  seen  after  the  development  of  the 
dental  tissue  has  been  more  fully  described,  on  the  borderland  of  calcifica- 
tion, between  the  completed  fully  calcified  tissue  and  the  formative  matrix 
as  yet  not  fully  impregnated  with  lime,  there  very  constantly  exists  a 
stratum  of  tissue  which  in  its  physical  and  chemical  properties  very  much 
resembles  calcoglobulin. 

It  would  seem,  therefore,  that  the  indestructible  organic  matrix  of  bone, 
cementum,  dentin,  and  the  cuticula  dentis  was  in  all  probability  com- 
posed of  this  " profoundly  modified"  albumin,  '^calcoglobulin." 

Hoppe-Seyler  believes  the  calcium  salt  which  chiefly  enters  into  the 
hardening  process  in  the  calcification  of.  bone,  dentin,  and  enamel,  is  a 
double  salt  of  carbonate  and  jphosphate,  one  equivalent  of  calcium  carbo- 
nate combined  with  three  equivalents  of  calcium  phosphate. 

ENAMEL. 

Definition. — Enamel  is  a  vitreous,  hyaline  substance^  covering  the 
entire  crown  of  the  tooth  in  varying  thickness,  and  composed  chiefly  of 
phosphate  and  carbonate  of  calcium. 

Fig.  131.  Fig.  132. 


Section  of  enamel  at  right  angles  to  the  course  Three    enamel-columns,   exhibiting  the  six- 

of  its  columns,  exhibiting  the  six-sided  character       sided  prismatic  and  waving  or  ovaricose  char- 
of  the  latter ;  highly  magnified.  acter  ;  highly  magnified. 

Histologically,  enamel  is  composed  of  numerous  minute  hexagonal 
prisms  (Fig.  131),  measuring  in  transverse  diameter  from  0.0034  to  0.0015 
millimetre  and  in  length  from  three  to  five  millimetres  (Frey),  and  having 


Fig.  130. — Dentinal  sheaths,  the  residue  which  remains  after  rlecaleification  of  dentin  with  strong  acids.    >(  70. 


Blood- 
vessel 


Pig.  13.3. — Section  of  developing  human  molar.     Enamel  teased  from  the  dentin,  and  showing  ends  of  enamel-rods. 

X  1000. 


Fig.  134.—^,  transverse  section  of  enamel-rods;  B,  longitudinal  section  of  enamel-rods:  C,  odontoblasts, 
showing  processes  ;  D,  odontoblasts,  fcetal  kitten  ;  E,  dentin,  showing  interglobular  spaces  ;  F.  dentin,  showing 
laminated  structure.     (After  Stowell.) 


Fig.  135. — Vertical  section  of  enamel-rods,  showing  their  varicosities.     X  350. 


PLATE   I. 


Showing  varicosed  enamel-rod?.     (After  Dr.  J.  Leon  Williams.) 


Showing  raricosed  enamel-rods  more  highly  magnified.     (After  Dr.  J.  Leon  Williams.) 


PLATE  II. 


Showing 


varicosed  enamel-rods  very  highly  magnified.     (After  Dr.  J.  Leon  Williams.) 


HISTOLOGY    OF    THE    DENTAL    TISSUES.  37 

a  common  direction  at  right  angles  to  the  surface  of  the  dentin  upon  which 
they  rest. 

These  prisms  are  known  as  enamel-prisms,  enamel-rods,  or  enamel-col- 
umns. As  a  rule,  the  rods  are  continuous  from  the  dentin  to  the  outer 
surface,  and  with  the  exception  of  numerous  varicosities,  are  the  same  size 
throughout  their  entire  length ;  they  are  not  perfectly  straight,  however, 
but  have  a  wave-like  or  spiral  course  (Fig.  132).  At  the  outer  surface, 
and  particularly  at  the  angles  of  the  crown,  numerous  short  rods  are  found, 
which  extend  only  a  little  distance  from  the  surface,  and  fill  in  the  inter- 
spaces between  the  longer  rods  caused  by  the  increase  in  the  circumfer- 
ence of  the  outer  surface  and  the  turning  of  the  angles. 

A  section  of  enamel  viewed  from  the  ends  of  the  rods  or  prisms  has  the 
appearance  of  a  finely  tessellated  pavement  (Fig.  133).  The  rods  are  hex- 
agonal in  outline  (Fig.  134,  A),  and  are  separated  from  each  other  by  an 
interprismatic  substance,  the  nature  of  which  has  formed  a  subject  for 
much  discussion  (Fig.  134,  B). 

The  individual  enamel-rods  appear  under  the  higher  powers  of  the 
microscoi)e  to  be  regularly  varicosed,  the  varicosities  not  interdigitating  as 
formerly  taught,  but  opposite  each  other,  and  the  interspaces  filled  with 
the  interprismatic  substance  (Fig.  135). 

Transverse  Striations. — With  the  exception  of  faint  transverse  stria- 
tions,  the  enamel-rods  seem  to  be  structureless.  Hertz  claimed  this  appear- 
ance was  due  to  intermittent  calcification  of  the  enamel-rods.  Kolliker 
and  Waldeyer  believed  the  striations  were  due  to  the  varicosities  of  the 
individual  fi»bres.  Bodecker  declares  that  normal,  fully  developed  enamel 
is  non-striated,  and  von  Bbner  holds  the  same  opinion,  and  claims  that  this 
appearance  of  transverse  striations  is  due  to  the  method  of  preparing  the 
specimens,  which  are  usually  mounted  in  Canada  balsam,  and  as  a  result 
suffer  from  a  slight  acid  reaction  sufficient  to  produce  the  striated  api)ear- 
ance.  Sudduth  and  Febiger  hold  to  the  opinion  of  Kolliker  and  Waldeyer, 
that  the  striations  are  due  to  the  varicosities.  Williams  also  maintains  the 
same  opinion,  and  in  his  recent  investigations  denies  the  statements  made 
by  Hertz,  Bodecker,  and  von  Ebner,  and  claims  that  while  in  some  specimens 
the  varicosities  are  dimly  apparent  in  some  parts,  they  are  decided  in  others, 
but  that  they  are  always  present.  It  has  also  been  stated  that  each  vari- 
cosity represents  a  calcified  ameloblast,  but  Williams  claims  that  he  has 
counted  fifteen  such  varicosities  within  the  length  of  a  single  ameloblast, 
and  that  he  has  never  found  less  than  eight  to  each  cell.  The  varicosities 
he  believes  to  be  due  to  the  globular  form  of  the  individual  enamel-globules 
which  build  up  the  enamel-rods.     (See  Plates  I.  and  II. ) 

Brown  Striae  of  Retzius. — With  low  powers  of  the  microscope  an- 
other and  larger  form  of  striation  is  visible,  consisting  of  brownish  lines 
(Fig.  136),  the  '^  brown  strite  of  Eetzius."  They  are  seen  in  broad  lines, 
nearly  or  quite  laarallel  with  the  outer  surface  of  the  enamel. 

Tomes  suggests  that  inasmuch  as  they  coincide  with  what  was  at  one 
time  the  outer  surface  of  the  enamel  cusp,  they  are  in  some  sense  marks  of 
its  stratification  in  its  primary  deposit.  Williams  is  of  the  opinion  that 
they  are  due  to  a  real  pigmentation. 


38  OPEEATIVE   DENTISTRY. 

Lines  of  Schreger. — Another  class  of  markings  upon  the  surface  of 
sections  of  enamel  are  known  as  the  ^Hines  of  Schreger."  These  lines  are 
invisible  by  transmitted  light ;  but  with  reflected  light  are  plainly  seen. 
They  are  well  defined  at  the  point  nearest  the  dentin,  but  become  gradually 
less  marked  as  the  outer  surface  of  the  enamel  is  reached  ;  irregularly 
formed  lines  extending  in  a  longitudinal  direction  with  the  enamel-rods  are 
sometimes  seen  in  the  enamel  near  the  surface  of  the  dentin.  They  have 
the  appearance  of  open  spaces  or  cavities,  and  are  sometimes  in  communi- 
cation with  the  dentinal  tubes.  Cracks  and  fissures  are  often  seen  upon 
the  surface  of  the  enamel,  but  these  have  no  special  significance  except  as 
they  may  be  predisposing  causes  of  dental  caries. 

Nasmyth's  Membrane. — Covering  the  enamel  of  young,  newly 
eru]3ted  teeth  is  a  thin  membrane,  the  cuticula  dentis,  or  ]^asmy th'  s  mem- 
brane. This  membrane  is  thought  to  be  formed  from  the  outer  layer  or 
tunic  of  the  enamel-organ,  and  measures  in  thickness  from  0.001  to  0.0013 
millimetre.  It  is  exceedingly  resistant  to  the  strongest  acids,  alkalies, 
boiling,  and  maceration,  but  is  soon  worn  from  the  teeth  by  the  friction  of 
mastication.     It  yields  no  gluten.     (KoUiker). 

Chemic  Composition  of  Enamel. — Enamel  is  the  hardest  structure 
of  the  body,  and  at  the  same  time,  by  the  arrangement  and  character  of 
its  component  parts  is  capable  of  great  resistance  to  mechanical  force  and 
the  attrition  due  to  the  mastication  of  food.  It  is  almost  if  not  entirely 
destitute  of  organic  matter,  and  possesses  no  nutritive  canals. 

Von  Bibra  gives  two  analyses  of  enamel,  the  first  from  an  adult  man, 

the  second  from  an  adult  woman. 

1.  2. 

Man.  Woman. 

Calcium  phosphate  and  fluoride 89.82  81.63 

Calcium  carbonate 4.37  8.88 

Magnesium  phosphate 1.34  2.55 

Other  salts ,. 0.88  0.97 

Cartilage ■•  •  ■      3.39  5.97 

Fat 0.20  a  trace 

100.00  100.00 

Organic  matter 3.59  5.97 

Inorganic  matter , 96.41  94.03 

100.00  100.00 

Williams  says,  "  Enamel  is  a  solid  mineral  substance,  and  the  finest 
lenses  reveal  not  the  slightest  difference  between  enamel  ground  moist 
from  the  living  tooth  and  that  which  has  lain  in  the  earth  for  a  hundred 
centuries;"  and  also,  that  '' mature,  completely  calcified  enamel  contains 
no  trace  of  organic  matter,  therefore  no  physiologic  change  is  possible  in 
completely  formed  enamel." 

The  chemic  analyses  which  have  been  published  from  time  to  time 
have  estimated  the  organic  material  in  the  enamel  of  a  human  adult  tooth 
at  from  two  to  seven  per  cent.  The  organic  material  in  these  analyses  was 
estimated  simi^ly  by  loss  of  weight  on  ignition.  This  is  evidently  the 
source  of  error,  for  no  account  is  made  of  water  being  a  constituent  of 
dried  enamel.     C.  Tomes  found  that  after  drying  elephant's  enamel  for  a 


Striation 


'^,' 


■•^,»;'' 


Crack  in  the 
enamel 


Striation 


Crack  in  tlie 
enamel 


\        \\i  J^wBm^  Dentin 
Fig.  136. — Section  of  enamel,  showing  the  brown  striations  of  Retzius.     (V.  A.  Latham.)     X  HO. 


Ameloblastic  layer 

and  ameloblastic 

processes 


Stellate  reticulum 


Forminff  dentin 


^  -  \   4  Dental  papillee 


r^G.  137. — Transverse  section  of  dental  follicle,  showing  first  layer  of  ameloblasts.     (V.  A.  Latham.)    X  325. 


Fig.  138. — Teased  section  of  developing  human  molar,  showing  the  ameloblasts.     (V.  A.  Latham.)     ;<  1000. 


♦  /| 


Fig.  139. — Developing  enamel,  showing  Tomes's  processes  at  A.     (R.  R.  Andrews.) 


Formina-  ameloblasts 


Stellate  reticulum 


Fig.  140.— Section  of  developing  human  molar,  showing  the  relations  of  the  various  stractures.     {Y.  A.  Latham.) 

X  1000. 


Formed  dentin 


Odontoblasts 


Stratum 
intermedium 


Ameloblasts 


Pulp 


Fig.  141.— Section  of  developing  human  tooth,  showing  ameloblasts  highly  magnified.     (Zeiss  one-twelfth  oil 

immersion.) 


Fig.  142. — Section  of  developing  tooth,  showing  ameloblasts  more  highly  magnified. 


St(  llatc  reticulum 


Outer  ameloblastic 
membrane 

Inner  ameloblastic 
membrane 


,  Stratum  intermedium 
I'^ormed  ameloblasts 


Formed  enamel 
Formed  dentin 


Odontoblasts 


\>.«       '    •' 


Fig.  143.— Transverse  section  of  developing  tooth,  showing  the  arrangement  of  the  tissues.     (After 

Andrews.)     X  275. 


HISTOLOGY    OF   THE    DENTAL    TISSUES.  39 

long  time  at  a  temperature  of  300°  F.  that  it  still  contained  about  four  per 
cent,  of  water. 

In  decalcifying  sections  of  fully  formed  enamel  by  the  aid  of  acids,  it  is 
found  that  the  interprismatic  substance  is  first  attacked,  and  the  rods  fall 
apart,  which  proves  conclusively  that  the  interprismatic  substance  is  a 
calcium  cement  material,  more  readily  acted  upon  than  the  rods  them- 
selves. If  the  process  of  decalcification  is  continued,  the  enamel-rods  are 
attacked,  and  the  whole  structure  is  destroyed,  leaving  behind  no  evidence 
of  an  organic  matrix. 

CALCIFICATION   OF   ENAMEL, 

Amelification  is  the  process  by  which  the  calcium  salts  are  deposited 
within  the  matrix  constructed  by  the  ameloblasts  for  the  formation  of 
enamel. 

As  previously  stated,  the  process  of  calcification  first  begins  in  the 
dentin  paiyiUaj  by  the  formation  of  a  layer  of  dentin  at  those  points  which 
are  denominated  the  lobes  of  the  morsal  edge  and  the  cusps  of  the  morsal 
surface. 

Upon  this  layer  of  dentin,  which  is  as  yet  only  partially  calcified,  the 
first  layer  of  ameloblasts  is  arranged  (Fig.  137).  These  cells  are  some- 
what in  the  form  of  columnar  epithelial  cells,  have  oval  nuclei  and  taper- 
ing processes  projecting  from  their  inner  ends, — Tomes's  processes  (Figs. 
138  and  139),  The  ameloblasts  Stand  close  together,  with  one  end  resting 
upon  the  newly  formed  dentin,  and  the  other  in  contact  with  the  stratum 
intermedium,  and  this  again  in  contact  with  the  stellate  reticulum  (Fig. 
140).  This  is  further  and  more  beautifully  shown  in  Fig.  141.  In  this 
illustration  the  ameloblasts  are  seen  resting  upon  the  formed  enamel,  while 
the  opposite  ends  are  in  contact  with  the  stratum  intermedium.  Fig.  142 
is  a  higher  magnification  of  the  same  section. 

Stratum  Intermedium. — In  the  earlier  stage  of  enamel  formation, 
various  observers  have  described  the  presence  of  what  has  appeared  to  be 
a  structureless  membrane  lying  between  the  odontoblasts  and  the  first  layer 
of  ameloblasts,  and  another  between  this  layer  of  ameloblasts  and  the 
stratum  intermedium,  the  formation  and  character  of  which  has  not  been 
demonstrated  (Fig.  143). 

Williams  has  designated  these  layers  by  the  terms  inner  and  outer 
ameloblastic  membranes,  and  describes  them  as  being  composed  of  a  finely 
fibrous  structure.  The  outer  layer  or  membrane  is  particularly  interesting 
from  the  fact  that  it  seems  to  be  composed  of  two  sets  of  fibres  running  in 
nearly  opposite  directions,  but  neither  direction  corresponding  with  the 
long  axis  of  the  ameloblasts. 

One  set  of  these  fibres  passes  in  a  somewhat  more  oblique  course  than 
the  others,  and  becomes  confiuent  with  the  ends  of  the  enamel-prisms, 
while  the  other  set  sweep  downward  in  a  circular  course,  crossing  the  more 
oblique-running  fibres  and  the  enamel-prisms  nearly  at  right  angles. 
Mummery  has  beautifully  shown  the  interlacing  of  these  fibres. 

Sometimes  both  sets  of  fibres  join  and  twist  about  each  other  in  a 
rope-like  design,  and  pass  along  the  course  of  the  enamel-prisms.    A  third 


40  OPERATIVE    DEKTISTRY, 

set  of  fibres  may  sometimes  be  seen  running  parallel  to  the  ends  of  the 
ameloblasts.  These  fibres,  he  thinks,  are  identical  with  the  j)lasm-strings 
first  discovered  by  Andrews,  which  are  often  visible  in  the  ameloblasts. 

With  a  magnifying  power  of  from  one  thousand  to  two  thousand  three 
hundred  diameters,  he  discovered  the  inner  and  outer  ameloblastic  mem- 
branes to  be  composed  of  several  layers  of  protoplasmic  strings  or  fibres. 
These  processes  or  strings  are  often  seen  to  emerge  from  the  inner  ends  of 
the  ameloblasts,  and  turn  to  the  right  and  left.  He  thinks  it  quite  possible 
that  the  structures,  which  he  has  designated  as  the  in7ier  and  outer  amelo- 
blastic membranes,  are  formed  by  the  accumulation  of  the  calcific  albuminous 
product  of  the  stratum  intermedium  within  the  meshes  of  these  plasm- 
strings,  which  spread  out  on  both  ends  of  the  ameloblasts,  forming  a  struc- 
ture resembling  a  membrane  (Fig.  144,) 

Blood-Supply  of  the  Enamel-Organ. — Wedl,  Magitot,  Tomes,  Sud- 
duth,  Andrews,  and  others  have  stated  that  they  have  uniformly  failed  to 
detect  blood-vessels  in  any  part  of  the  enamel- organ.  A  reference  to  Fig. 
145  will  show  the  enamel-organ  to  be  abundantly  supplied  with  blood- 
vessels, which  cover  its  entire  outer  surface.  But  Williams  has  shown 
conclusively  in  recent  papers  published  in  the  Dental  Cosmos  for  1896  and 
1897,  accomiDanied  by  numerous  most  excellent  photo-micrographs,  that 
not  only  are  blood-vessels  seen  within  the  enamel-organ,  but  that  they 
are  found  within  the  stratum  intermedium  in  an  intricate  plexus.  The 
ameloblasts  are  surmounted  by  epithelial"  papillae,  which  Williams  terms 
''secreting  papillse"  (Figs.  146  and  147),  and  these  are  surrounded  by  a 
free  distribution  of  cai^illary  loops.  The  ameloblasts  seem  to  be  con- 
nected with  the  papillsB  by  root-like  processes,  which  are  lost  in  the  sub- 
stance of  the  j)apilla  to  which  they  belong. 

The  papillae  (Figs.  148  and  149)  are  from  five  to  six  times  as  large  as 
the  ameloblasts,  and  may  therefore  supply  from  twenty  to  twenty-five 
ameloblasts.     These  he  believes  to  be  secreting  organs. 

He  further  states  that,  although  the  stratum  intermedium  in  forming 
human  enamel  is  not  very  striking  in  its  resemblance  to  glandular  tissue, 
aside  from  the  arrangement  of  its  blood-vessels,  that  nevertheless  in 
studies  of  the  evolution  of  the  enamel-organ  of  the  mouse  and  rat  its  place 
among  glandular  structures  at  once  becomes  evident.  He  also  states  as 
his  opinion  that  the  function  of  the  stratum  intermedium  is  undoubtedly 
to  select  from  the  blood  brought  to  it  by  its  capillary  vessels  the  necessary 
material  for  the  construction  of  the  enamel.  He  explains  the  difficulty  in 
the  theory  of  the  formation  of  enamel  before  the  development  of  the 
stratum  intermedium,  by  suggesting  that  the  material  necessary  for  the  com- 
mencement of  enamel  formation  is  stored  u/p  in  the  stellate  reticulum  of  the  enamel- 
organ. 

Charles  Tomes  does  not  agree  with  Williams  in  his  conclusions  in  refer- 
ence to  the  presence  of  blood-vessels  in  the  stratum  intermedium  or  in  the 
supposed  secreting  function  of  the  papillae  of  the  stratum  intermedium. 

Spee  and  Andrews  have  taught  that  the  process  of  calcification  of  the 
enamel  was  due  to  the  deposition  of  "droplets"  or  spherules  of  calco- 
globulin  formed  within  the  ameloblastic  cells,  and  excreted  or  shed  out 


stellate  reticulum  ^> 


Masses  of   - 
calcoglobulin 
in  calcifyiiia 
amelobiasts 


Stellate  reticulum 


Outer  ameloblastic 
membrane 

Inner  ameloblastic 
membrane 


Stratum  intermedium 
Calcifying  enamel 


Dentin 


Fig.  144.— Developing  tooth  of  embryo  lamb.     (After  Andrews.)     X  105. 


Capillary 
blood-vessels 


Forming 

enamel 

Enamei-organ 


Dental  pulp 


Blood-vessel, 

arising  from 

base  of  dental 

papilla 


Formed 
enamel 


Formed 
dentin 


Blood-vessel, 
arising  from 
base  of  dental 
papilla 


Bone 


Fig.  145.— Vertical  section  of  central  incisor  of  human  foetus  (injected),  showing  blood-supply  of  enamel- 
organ.    (V.  A.  Latham.) 


Papillary  layer 

ameloblasts  lyina; 

beneath 


Formed  enamel 


Formed  dentin 


Fig.  146. — Transverse  section  of  dental  follicle  of  rat,  showing  papillary  layer.     (Y.  A.  Latham.)     X  90. 


Capillary  blood-vessel 


Fig.  147. — Section  of  forming  enamel  from  jaw  of  rat,  showing  enamel  papillae,  blood-vessels,  and  fibrillse. 

(V.  A.  Latham.)     X  325. 


Fig.  148.— Section  of  incisor  of  a  rat.    (J.  Leon  Williams.)     X  80.    A,  capillary  loops  torn  out  of  secreting 
papillse ;  B,  secreting  papillae  after  removal  of  capillary  loops  ;  C,  ameloblasts  ;  D,  enamel ;  £,  dentin. 


Spherules  of  calcoglobulin 


Fig.  149. — Ground  section  of  developing  tooth  of  rat,  showing  secreting  papillas  of  Williams.     (Von  Koch 

method.)     (V.  A.  Latham.)     X  97. 


Fig.  150.— Forming  enamel.    (R.  R.  Andrews.)    A,  globular  bodies  of  calcoglobulin  forming  enamel-rods. 


Fig.  151. — Section  of  forming  enamel,  slmwing  nucleus  of  ameloblasts  and  calcospherites  forming  the 

enamel-rods.     (R.  R.  Andrews.) 


HISTOLOGY    OF    THE    DENTAL    TISSUES,  41 

(Kolliker)  "by  them  at  the  extremities  nearest  to  the  odontoblastic  laj^er  to 
form  or  build  up  the  individual  enamel-rods,  the  fibres  of  Andrews,  acting 
as  a  sort  of  reticulum  or  scaffolding  to  determine  their  arrangement. 

Williams  states  that  the  "albumin-like  substance  secreted  from  the 
blood-vessels  by  the  cells  of  the  stratum  intermedium"  is  absorbed  by  the 
ameloblasts  and  deposited  by  them  in  globular  masses,  which  he  terms 
"  enamel-globules,"  to  form  the  enamel-rods  (Fig.  150). 

He  thinks  these  ^'globular  masses  of  spongioplasm"  are  successively 
formed  within  the  ameloblasts  themselves.  "The  cytoplasm  of  the  amel- 
oblasts has  a  fairly  uniform  structure,  which  consists  of  a  number  of 
globular  masses  of  spongioplasm  of  the  same  diameter  as  the  cell,  and 
united  longitudinally  by  somewhat  coarser  plasm -strings,  the  fibres  of 
Andrews. 

He  says  further,  ' '  there  are  many  indications  that  these  '  enamel-glob- 
ules' are  formed  by  the  nucleus  of  the  ameloblast,  and  they  appear  to  pass 
down  the  cell  by  the  natural  process  of  growth  as  new  ones  are  formed 
above,  to  be  finally  shed  off  the  inner  ends  of  the  cells  onto  the  surface  of 
the  forming  enamel,  where  they  become  completely  infiltrated  with  the 
albumin-like  lime-conveying  substance  and  calcified"  (Fig.  151). 

The  "enamel-globules,"  which  are  uniform  in  size  (Fig.  152),  are, 
according  to  Williams,  quite  distinct  from  the  more  transparent  and 
irregularly  sized  masses  of  calcoglobulin,  and  that  the  enamel-rods  are 
built  up  by  the  successive,  rhythmical,  orderly  deposit  of  these  "enamel- 
globules,  ' '  while  the  larger  and  more  irregular-sized  bodies  of  calcoglobulin 
melt  and  flow  together  to  form  the  interprismatic  substance. 

The  elder  and  younger  Tomes  both  held  the  theory  that  the  cell- wall  of 
the  ameloblasts  may  be  calcified  to  form  the  interprismatic  substance, 
while  the  cell-contents  solidify  into  the  enamel-rods  proper. 

Heitzmann  and  Bodecker  promulgated  the  theory  that  the  interpris- 
matic substance  was  composed  of  a  reticulum  of  living  matter,  and  that 
enamel  formation  was  due  to  the  breaking  up  of  the  ameloblasts  into  "em- 
bryonal corpuscles,"  which  afterwards  become  calcified  to  form  the  enamel- 
rods.  This  theory  for  a  time  dominated  the  minds  of  a  verj^  large  propor- 
tion of  American  dentists,  influencing  their  practice  accordingly. 

This  view  taught  that  physiologic  changes  took  i)lace  from  time  to 
time  in  the  structure  of  the  enamel  through  its  reticulum  of  living  matter. 
Later  investigations  have  demonstrated  the  fact  that  these  authors  were 
mistaken  in  their  conclusions,  and  as  a  result  the  theory  has  to-day  few 
advocates. 

DENTIN. 

The  dentin  is  an  organic  calcified  tissue,  non-vascular,  less  dense  than 
enamel,  and  harder  than  bone,  which  it  somewhat  resembles.  It  forms 
the  central  portion  and  greater  bulk  of  the  hard  structures  of  a  tooth,  com- 
pletely investing  the  pul^)  from  which  it  is  generated  ;  it  is  covered  and 
protected  at  the  crown  by  a  layer  of  enamel,  while  the  root  is  encased  with 
a  layer  of  cementum  (Figs.  153  and  151.)  If  the  enamel  and  cementum 
should  be  removed,  the  dentin  would  still  retain  the  general  form  and 
characteristic  features  of  the  tooth. 


42  OPERATIVE    DENTISTRY. 

The  dentin  is  a  dense,  liiglily  elastic  substance,  white  or  yellowish- 
white  in  color,  and  to  some  extent  translucent. 

Vascular  canals  are  occasionally  seen  in  human  dentin,  but  they  are 
to  be  considered  as  abnormal  conditions. 

The  dentin  consists  of  an  organic  matrix  strongly  impregnated  with  the 
calcium  salts. 

The  Matrix. — The  matrix  of  fully  formed  dentin  appears  to  be  struc- 
tureless, although  there  are  instances  in  which  there  are  indications  that 
at  some  time  during  the  development  of  the  dentin  connective-tissue  fibres 
were  present  (Mummery). 

The'  proportions  of  the  organic  and  inorganic  constituents  are  so  varia- 
ble that  no  chemic  analysis  could  be  considered  other  than  approxi- 
mating the  exact  amounts  in  even  the  same  individual,  as  the  relative 
quantities  are  constantly  changing  from  childhood  to  old  age.  The  rela- 
tive i^roportions  are  also  very  variable  in  different  individuals. 

Von  Bibra  gives  the  following  analysis  of  perfectly  dried  dentin,  the 
first  an  adult  man  and  the  second  a  woman  twenty-five  years  old  : 

1.  2. 

Man.  Woman. 

Organic  matter  (tooth  cartilage) 27.61  20.42 

Fat 0.40  0.58 

Phosphate  and  fluoride  of  calcium 66.72  67.54 

Carbonate  of  calcium.    3.36  7.97 

Phosphate  of  magnesium 1.08  2.49 

Other  salts. 0.83  1.00 

100.00      100.00 

Galippe  gives  the  relative  proportions  of  organic  and  inorganic  matter 
in  dentin  as  follows  : 

Water  and  organic  matter 25.29 

Mineral  matter 74. 71 

100.00 
Mineral  Matter. 

Soluble  ash  (alkaline  chlorides  and  phosphates) 0.54 

Calcium  carbonate - 0.35 

Magnesium  carbonate 1.13 

Calcium 45.11     ' 

Magnesium 1.67 

Phosphoric  acid 23. 70 

Silicates 0.04 

Undetermined 1.30 

Black,  in  his  experiments  upon  the  ' '  Physical  Characters  of  the  Human 
Teeth,"  Dental  Cosmos,  1895,  found  the  analysis  of  the  dentin  of  two  hun- 
dred and  sixty-eight  teeth  taken  from  one  hundred  and  eleven  different 
persons  to  giv^e  the  following  results  : 

Average  age  of  the  individuals  from  whom  the  teeth  were  taken 

was,  in  years 32.33 

Specific  gravity  of  the  dentin 20.92 

Percentage  of  water 11.06 

Percentage  of  lime  salts 63.54 

Percentage  of  organic  matter 25.36 


Fig.  152. — Section  of  forming  enamel,  calcoglobulin  spherites  being  deposited  to  form  the  enamel-rods, 

(R.  R.  Andrews.) 


Knamel 


Dentin 
Pulp-cavity 


,-V 


r"  ■ 

•  fe 

\] 

",.  / 

'^ 

U. 

.i^-'-: 

Mi 

> 

'; 

■:h 

Ifi 

iia'^ 

M'liiB 

^- 

k"' 

w  ^^ 

Cementum 


Fig.  153  —Longitudinal  section  of  an 
incisor.    (After  Stowell.) 


Fig.  154. — Longitudinal  section  of  an  inferior 
molar.    (  After  Stowell . ) 


Pulp-canal 


Dentinal  tubuli 


Cementum 


Secondary  dentin 


Fig.  155. — Transverse  section  of  root  of  human  bicuspid,  showing  radiation  of  the  dentinal  tubuli. 


Fig.  156.— Normal  dentin  at  dento-enamel  junction,  showing  dentinal  tubuli.    (F.  B.  Noyes.)    X  760. 


HISTOLOGY    OF    THE    DENTAL    TISSUES. 


43 


The  Dentinal  Tubuli. — The  matrix  is  everywhere  permeated  by  a 
system  of  parallel  caualiculi  or  tubuli,  the  dentinal  tiibuU,  which  radiate 
from  the  pulp-cavity  towards  the  outer  surface  of  the  dentin  (Fig.  155). 
The  diameter  of  the  tubuli  is  from  0.0011  to  0.0023  millimetre  and  up- 
ward (Frey).     (Plate  III.) 

The  dentinal  tubules  are  similar  to  the  caualiculi  of  bone  in  that  they 
are  provided  with  a  special  lining  layer  or  sheath,  the  dentinal  sheath  of 
Neumann. 

In  following  the  course  of  the  dentinal  tubuli,  it  will  be  noticed  that 
they  do  not  form  a  straight  line  in  their  passage  from  the  iDulp-canal  to  the 
surface  of  the  dentin,  but  that  they  describe  two,  more  often  three,  undu- 
lating curves,  and  within  these  many  very  small,  more  or  less  angular  or 
spiral  bends,  of  which  about  two  hundred  may  be  counted  in  the  length 
of  a  line  (Fig.  156).     (Eetzius. ) 

It  is  further  observed  that  like  the  caualiculi  of  bone  the  dentinal  tubuli 
give  off  numerous  branches  in  their  course  which  unite  with  neighboring 
tubuli  and  with  each  other  (Fig.  157).     As  the  tubuli  approach  the  sur- 

FiG.  157. 


Section  of  root,  parallel  to  dentinal  canals,     (.\fter  .stowell.) 

face  the  division  is  more  rapid,  and  the  size  of  the  branches  is  correspond- 
ingly decreased.  At  the  external  surface  of  the  dentin  many  of  the 
tubules  unite  by  anastomosis  (Fig.  158),  others  terminate  in  the  granular 
layer  of  Purkinje  and  Tomes,- while  a  third  set  penetrates  the  cementum 
and  may  unite  with  its  lacunae  through  their  caualiculi  ;  or  enter  the 
enamel  by  means  of  the  open  spaces,  or  interstices  between  the  enamel- 


FiG.  158. 


1,  tubuli  of  dentin  ;  2,  enamel. 


rods,  already  referred  to  as  existing  in  that  portion  of  the  enamel  next  to 
the  dentin  (Fig.  159).  This  system  of  canals  terminates,  or  rather  has  its 
beginning,  in  free  openings  upon  the  internal  surface  of  the  pulx^-canal. 


44  OPERATIVE    DENTISTRY. 

Fig.  160,  which  is  highly  magnified,  shows  the  dentinal  fibrillee  crossing 
from  the  dentin  to  the  enamel  and  apparently  passing  between  the  enamel 
rods. 

The  Dentinal  Sheaths. — The  dentinal  sheaths,  or  walls  of  thetubuli, 
as  they  are  termed,  are  composed  of  a  singularly  indestructible  substance, 
which  is  peculiarly  resistant  to  the  action  of  acids,  boiling  in  caustic  alka- 
lies, or  to  putrefaction  ;  caries  does  not  destroy  them,  and  they  can  also  be 
demonstrated  in  fossil  teeth;  this  substance  is  in  all  probability  "cal co- 
globulin." 

Keumann  and  Henle  are  of  the  opinion  that  the  dentinal  sheaths  are 
calcified.  The  existence  of  the  dentinal  sheaths  can  be  demonstrated  by 
decalifying  the  dentin  with  strong  acids.  This  process  requires  several 
days  for  its  accomplishment.  The  residue  is  found  to  be  composed  of  a 
tangled  mass  of  a  fibrous-appearing  material  (Fig.  161)  which  upon  care- 
ful examination  is  found  to  be  composed  of  the  dentinal  sheaths. 

Magitot  and  Sudduth  are  of  the  opinion  that  the  dentinal  sheaths  do 
not  exist  as  structures  distinct  from  the  fibrils. 

Eose  demonstrated  the  presence  of  the  sheaths  of  Neumann  by  Golgi's 
rai^id  method  of  staining  with  nitrate  of  silver.  If  the  tooth  is  previously 
prepared  by  Weil' s  method,  the  soft  parts,  including  the  dentinal  fibrils, 
do  not  take  the  stain,  so  that  in  transverse  section  the  fibril  is  seen  as  a 
bright  point  in  the  centre  of  the  black  dentinal  sheath.     (Plate  III.) 

Tomes  is  inclined  to  the  belief  that  the  dentinal  tubuli  possess  definite 
lining  walls  ;  but  yet  suggests  that  it  is  possible  that  their  seeming  exist- 
ence may  be  the  result  of  the  action  of  the  agents  used  in  the  preparation 
of  the  specimen.  He  also  calls  attention  to  the  fact  that  that  part  of  the 
matrix  immediately  embracing  the  fibrils  differs  in  chemic  constituents 
from  that  which  makes  up  the  bulk  of  the  matrix. 

Dentinal  Fibrils.— The  dentinal  tubules  (Plate  IV.)  are  occupied  for 
their  entire  length  by  solid  fibrillse  or  processes  given  off  from  the  odonto- 
blasts, which  are  known  as  Tomes^  s  fibrils,  or  the  dentinal  fibrils,  the  function 
of  which,  it  is  supposed,  is  to  transmit  sensation  and  possibly  nutritive 
fluid  from  the  plasma  of  the  blood.  These  questions,  however,  have  never 
been  satisfactorily  settled.  The  fibrils  of  Tomes  are  solid  structures  which 
fill  the  lumina  of  the  dentinal  sheaths,  so  that  it  would  seem  impossible  for 
them  to  carry  fluid  except  by  a  process  of  osmosis.  Histologists  have  not 
been  able  to  determine  the  real  nature  of  the  fibrils,  though  there  is  no 
doubt  from  the  clinical  stand-point  that  they  carry  sensation. 

Some  writers  have  asserted  that  the  terminal  nerve-fibres  of  the  pulp 
pass  between  the  odontoblasts,  and  either  unite  with  the  dentinal  fibrils 
or  accompany  them  into  the  dentinal  tubuli.  Others  are  of  the  opinion 
that  the  non-medullated  fibres  of  the  pulp  become  united  with  the  stellate 
layers  of  cells  which  lie  beneath  and  are  connected  with  the  odontoblasts, 
and  that  thus  the  power  of  carrying  sensitive  impressions  is  conveyed  to 
the  dentinal  fibrils  ;  while  still  others  have  thought  that  the  sensitiveness 
of  the  dentin  was  due  to  the  transmission  of  vibrations  to  the  pulp,  through 
a  fluid  contained  in  the  tubules,  or  some  other  inert  conductor. 

Boll  (1868)  was  the  first  investigator  to  make  authentic  observations  in 


PLATE   III. 

..  ^  ^  #  #     -..^ 


ifi 


'^     A    ''    ^        ■  <*    ^ 


k\ 


f 


,  ^ 


,^      A 


if^ 


«  "    "   •  * 
1 


'.     '^     «  ,j"    :  i  i' 


•r«*» 


'I 


k 


*    H 


#        m  i 

•  •  f 


^•\        #^        »■•■*  »^ 


^   n    ^      «  #  ■^^. 


Normal  dentin  showing  tubuli  in  cross  section.     (F.  B.  Noyes.)     Highly  magnified. 


PLATE  IV. 


Normal  dentin  showing  tubuli  in  longitudinal  section.     (F.  B.  Noyes.)     Highly  magnified. 


Dentinal  tubuli 

entering  the 

enamel 


Dentin 


Fig.  159.-Sectiou  of  dentin  and  enamel,  showing  tubuli  entering  the  enamel.     (V 


Ameloblasts 


(V.  A.  Latham.) 
Formed  enamel 


Fig.  160.— Vertical  section  of  developing  h 


Odonto- 

blasta 


Blood- 
vessei. 


umau  UM,ili,  slL.winjf  dentinal  fibres  passing  from  the  dentin  to  the 
enamel.     >(  1000. 


Fig.  161.— Dentinal  sheaths  isolated  by  decalcification  of  the  dentin.     X  273. 


Enamel 


Interglobular 


Interglobular 
b  paces 


Dentin 


Fig.  162.— Vertical  section  of  enamel  and  dentin,  showing  interglobular  spaces.    X  50. 


HISTOLOGY    OF    THE    DENTAL   TISSUES.  45 

the  endings  of  the  nerves  of  the  pulp.  His  observations  were  made  upon 
the  pulps  of  the  canine  teeth  of  young  rabbits  and  guinea-pigs,  some  of 
which  were  stained  with  gold  chloride  ;  others  were  fixed  for  a  short  time 
in  dilute  chromic  acid  solution,  teased  out  and  mounted  in  this  solution. 
With  the  gold-chloride  method  the  results  were  negative.  The  chromic 
acid  method  enabled  him  to  make  out  numerous  medullated  and  non- 
medullated  nerve-fibres  in  the  tooth-pulp.  Lying  beneath  the  odonto- 
blastic layer  was  an  especially  dense  net-work  of  non-medullated  ^erve- 
fibres.  From  this  net- work  he  discovered  fine  fibrillae  passing  between  the 
odontoblasts,  some  of  which  could  be  traced  for  a  considerable  distance 
beyond.  He  did  not,  however,  succeed  in  tracing  these  fibrillte  into  the 
dentinal  tubules,  but  he  felt  sure,  although  unable  to  demonstrate  it,  that 
they  did  enter  the  tubules,  and  he  assumes  there  are  two  kinds  of  tubules 
in  the  dentin,  those  which  carry  the  dentinal  fibrils  and  those  which  carry 
the  nerve-fibrils. 

Underwood  and  Mummery  have  demonstrated  by  the  gold-chloride 
method  the  presence  of  nerve-fibres  arising  from  the  deeper  portions  of 
the  pulp  which  run  directly  to  the  dentin,  and  appeared  as  though  they 
entered  it,  thus  far  confirming  the  observations  of  Boll. 

Tomes  says,  the  dentinal  ''fibrils  are  not  nerves  in  the  ordinary  sense, 
and  were  never  supposed  to  be  ;  but  there  are  many  examples  of  cellular 
structures  which  are  connected  with  the  termination  of  sensory  nerve-fibres, 
such  as  the  goblet-cells  in  the  olfactory  membrane  of  the  frog,  and  it  is 
quite  possible  that  the  odontoblasts  may  stand  in  some  such  relation  to  the 
nerves  of  the  pulp,  the  terminations  of  which  have  even  not  yet  been 
satisfactorily  traced." 

Mummery  found  later  that  by  following  Boll's  method  of  preparation, 
by  Weil's  process,  and  also  by  decalcification  processes,  that  he  could  trace 
a  great  number  of  fibres  which  pass  from  the  pulp  to  the  dentin,  these 
fibres  being  much  smaller  than  the  dentinal  fibrillse. 

He  was  not,  however,  able  to  see  what  became  of  them  after  they 
reached  the  dentin.  By  means  of  various  stains,  especially  iron,  followed 
by  tannin,  he  was  able  to  show  them  stained,  and  they  appear  to  be  trace- 
able backward  into  nerve-trunks  a  little  below  the  surface  ;  these  trunks 
consisted  of  bundles  of  non-medullated  nerve-fibres,  in  fact,  axis-cylinders. 
He  believes  the  dentin  is  permeated  by  dentinal  fibres  and  also  by  much 
finer  fibres,  some  of  which  run  up  towards  it  from  fusiform  cells  which 
lie  near  the  surface  of  the  pulp,  while  others  appear  to  come  from  points 
deeper  down  in  the  pulp,  and  to  be  devoid  of  fusiform  enlargements. 

Charters  White  is  of  the  opinion  that  these  fibres,  after  they  leave  the 
bases  of  the  germinal  corpuscles,  enter  the  fibrous  tissue  of  the  pulp  and 
become  fused  in  the  outer  coat  of  the  nerve,  but  that  as  yet  these  facts 
have  not  been  positively  demonstrated. 

Coleman  compares  the  odontoblasts  to  tactile  corpuscles.  Pacinian 
bodies,  the  rods  and  cones  of  the  retina,  and  the  termination  of  the  audi- 
tory nerves  in  the  cochlea.  He  believes  that  a  connection  exists  between 
the  odontoblasts  and  the  nerve-fibres,  but  does  not  consider  it  as  absolutely 
necessary  to  make  out  such  a  connection  between  the  nerve-fibres  and  the 


46  OPERATIVE    DENTISTRY. 

sensitive  part.  He  says,  "  The  impression  received  by  the  long  processes 
of  the  odontoblasts  might  be  conducted  from  these  bodies  through  numer- 
ous cells  which  intervene  between  them  and  the  nerve-fibres,  or  possibly 
the  connective  tissue  of  the  pulp  may  perform  this  office." 

Magitot  speaks  very  positively  of  the  terminal  fibrils  of  the  nerves  of 
the  pulp  being  continuous  with  a  layer  of  reticulate  cells,  which  lie  imme- 
diately beneath  the  odontoblasts,  and  that  these  communicate  freely  with 
the  processes  of  the  odontoblasts,  so  that  there  is  a  very  direct  communica- 
tion between  the  nerves  of  the  pulp  and  the  dentinal  fibrils. 

Sudduth  has  never  been  able  to  demonstrate  any  connection  between 
the  terminal  nerve-fibres  of  the  pulp  and  the  odontoblasts. 

Klein  maintains  that  the  only  funiction  of  the  odontoblasts  is  to  form 
the  dentin  matrix,  and  that  the  dentinal  fibrils  are  long  processes  given 
off  from  the  dee^Dcr  cells  of  the  dentinal  papilla,  and  that  they  run  up 
between  the  odontoblasts  and  enter  the  dentinal  canaliculi. 

Eobertson  found,  in  examining  sections  of  the  tooth-pulp  of  the  ox 
which  were  i^repared  by  fixing  and  teasing  in  osmic  acid,  that  the  axis- 
cylinders  of  the  meduUated  nerve-fibres  lose  their  medullary  sheaths,  and 
after  extending  for  a  greater  or  less  distance,  become  continuous  with  the 
pulp  iDrocesses  of  the  odontoblasts,  which,  therefore,  with  their  dentinal 
processes  may  be  considered  as  nerve- end  organs. 

Bodecker  says,  "In  specimens  of  nine-month  foetal  pulps,  sufficiently 
stained  with  gold  chloride,  I  have  observed  that  the  medullated  nerve- 
fibres  upon  approaching  the  periphery  of  the  pulp  are  destitute  of  their 
myelin  sheath,  and  now  become  bare  axis- cylinders,  split  up  into  numer- 
ous extremely  delicate  beaded  fibrillse,  the  axis-fibrillae. " 

Dentz  made  sections  from  embryos  in  which  about  one-half  of  the 
dentin  was  formed,  and  discovered  pear-shaped  bodies  arranged  with  great 
regularity  a  short  distance  within  the  border  of  the  dentin,  the  small 
ends  being  directed  towards  the  pulp  and  connected  by  the  small  ends 
with  one  or  more  dentinal  tubes.  Each  of  these  pear-shaped  bodies  had 
two  or  three  nuclei,  and  upon  the  whole  quite  closely  resemble  certain 
forms  of  nerve-end  organs. 

Eetzius  demonstrated  (1895),  by  the  aid  of  Golgi's  method  of  staining 
sections  from  the  teeth  of  rats,  that  the  nerves  of  the  pulp  resolve  them- 
selves into  fine  varicosed  fibrils,  which  extend  through  a  layer  of  odonto- 
blasts as  far  as  the  dentin,  but  did  not  x)enetrate  into  the  latter. 

Huber  found  by  the  use  of  the  intravenous  methylene-blue  method  of 
Ehrlich, — injection  of  a  methylene-blue  normal  salt  solution  into  the  ves- 
sels of  a  narcotized  animal  which  x^roduces  a  stain  of  the  peripheral 
nerves, — in  which  a  one  per  cent,  of  methylene-blue  normal  salt  solution 
was  used,  was  injected  into  the  carotid  artery  of  a  rabbit  immediately 
after  killing  it  with  chloroform.  Thirty  minutes  later  the  jaw  was 
removed,  broken  open,  and  the  teeth  removed,  care  being  taken  not  to 
injure  the  x)ulps.  The  pulps  were  then  removed  and  placed  at  once  upon 
a  slide  moistened  with  a  normal  salt  solution. 

Such  freshly  prepared  specimens  showed  the  axis- cylinders  of  the  pulp- 
nerves  stained  with  the  characteristic  blue  color,  the  other  tissues  not  at 


HISTOLOGY    OF   THE    DENTAL    TISSUES.  47 

all  or  only  faintly  blue.  Sucli  specimens  must  he  fixed  at  once,  as  the 
color  will  otherwise  fade  very  quickly.  As  fixatives,  Huber  used  a  satu- 
rated solution  of  ammonium  picrate,  or  a  solution  of  ammonium  molyb- 
date.  The  former  was  mounted  in  a  mixture  of  glycerol  and  the  ammo- 
nium picrate  solution,  the  latter  dehydrated  and  mounted  in  balsam.  By 
these  methods  the  tissues  of  the  pulp  become  very  clear. 

In  examining  the  terminal  branches  of  the  medullated  nerve-fibres  of  the 
tooth-pulp,  he  found  that  on  approaching  the  surface  of  the  pulj)  they  lose 
their  medullary  sheath,  and  the  non-medullated  terminal  branches,  after 
repeated  division,  form  a  plexus  immediately  beneath  the  odontoblasts. 

The  non-medullated  terminal  branches  are  often  beset  with  nuclei ; 
they  branch  and  rebranch  into  long,  delicate  varicose  fibres  which  may 
often  be  followed  for  long  distances. 

This  accords  with  the  observations  of  Eetzius  with  the  Golgi  method. 
Huber  found  as  did  Eetzius,  "that  terminal  fibrils  given  off  from  the 
plexus  of  a  varicose  fibre  found  under  the  odontoblasts  pass  uj)  between 
the  cells,  to  terminate  usually  in  fine  granules  near  the  free  end  of  the  odonto- 
blasts. Xow  and  then  some  small  fibril  may  be  traced  as  it  takes  a  tangen- 
tial course  over  the  free  ends  of  the  odontoblasts,  as  was  found  hy  Eetzius." 

These  observations,  he  thinks,  taken  with  those  of  Eetzius,  ''warrant 
the  statement  that  the  terminal  branches  of  the  i)ulp-nerves  end  between 
the  odontoblasts  near  their  free  surface,  occasionally  between  these  cells 
and  the  dentin,  and  that  they  do  not  make  any  connection  with  the  odonto- 
blasts nor  with  any  of  the  cellular  elements  of  the  x)ulp." 

He  was  never  able  to  trace  any  nerve-fibril  beyond  the  odontoblastic 
layer. 

Interglobular  Spaces. — The  "  interglobular  spaces  of  Czermack"  are 
a  system  of  irregular  cavities  of  extreme  variableness  in  size,  which  exist 
normally  in  the  dentin,  and  are  the  interstices  or  sj^aces  between  the 
rounded  projections  of  numerous  spheroidal  or  rounded  bodies  or  masses 
grouped  together  within  the  basis  substance  of  this  tissue,  and  designated 
as  dentin  glohides  (Figs.  162  and  163).  They  are  found  principally  at  the 
union  of  the  dentin  with  the  cementum,  where  they  are  small  and  very 
numerous,  forming  what  is  generally  known  as  the  "granular  layer  of 
Tomes"  (Fig.  164). 

Many  of  the  dentinal  tubuli  have  their  endings  in  these  spaces.  The 
granular  layer  is  also  found  in  that  portion  of  the  dentin  which  lies  be- 
neath the  enamel,  but  in  this  location  it  is  not  so  strongly  marked. 
Although  the  interglobular  spaces  are  most  numerous  at  the  periphery  of 
the  dentin,  they  are  not  confined  to  this  location,  but  may  be  found  in  all 
parts  of  this  tissue.  These  spaces,  which  in  dried  sections  of  dentin 
appear  as  open  spaces,  with  irregular  outlines  and  sharp -pointed  processes, 
extending  in  all  directions,  giving  them  the  appearance  of  lacunae,  are 
in  the  fresh  state  filled  with  calcoglobulin  which  has  not  become  fully 
calcified. 

Broomell  claims  they  are  filled  with  a  soft  living  plasma,  having  a 
structural  arrangement  similar  to  the  basis  substance  or  matrix  of  the. 
dentin. 


48  OPERATIVE    DENTISTRY. 

Tomes  is  inclined  to  tLe  opinion  that  the  larger  interglobular  si^aces 
found  in  the  deeper  portions  of  the  dentin  ought  not  to  be  considered  as 
a  normal  condition,  but  rather  as  an  indication  of  an  arrested  development. 

The  dentinal  tubuli  are  not  arrested  by  the  interglobular  spaces,  but 
pass  through  them  without  interrux)tion  in  their  course. 

Bodecker  claims  that  the  spaces  of  the  granular  layer  are  filled  with 
living  plasma,  and  that  through  this  the  soft  fibrils  within  the  tubuli  are 
in  communication  with  the  soft  contents  of  the  lacunae  and  the  canaliculi 
of  the  cementum. 

Incremental  Lines. — Certain  lines  are  to  be  seen,  particularly  in  the 
crown  of  the  tooth,  indicating  the  laminated  structure  of  the  dentin  ; 
these  have  been  called  the  "  contour  lines  of  Owen"  and  the  "incremental 
lines  of  Salter"  (Fig.  165).  They  find  their  explanation  in  the  laminar 
growth  of  the  dentin,  as  already  indicated. 

Development  of  the  Root. — The  root  of  the  tooth  is  formed  as  a 
result  of  the  progressive  lengthening  of  the  pulp  (Fig.  166  and  Fig.  167) 
and  the  continued  production  of  Tomes' s  fibres,  of  the  canaliculi  and  the 
ground  substance  or  matrix,  through  the  agency  of  the  odontoblasts  or 
other  formative  cells.  The  process  is  the  same  as  that  already  described 
in  the  development  of  the  crown, — viz.,  the  formation  of  cup-like  layers  or 
laminae  one  within  the  other. 

If  a  forming  tooth  is  examined  at  that  stage  in  which  the  crown  has 
been  completed,  a  deep  cup-shaped  depression  will  be  noticed  over  the 
whole  radial  end  of  the  crown,  this  being  occupied  by  the  formative  pulp. 
The  deposition  of  calcoglobulin  begins  at  the  outer  circumference  of  the 
pulp,  building  each  time  a  quoit-like  layer,  with  its  rim  always  at  the 
outer  circumference  of  the  pulp  and  its  convexity  directed  towards  the 
crown.  As  fast  as  the  dentin  of  the  root  is  formed,  it  is  covered  by  a 
deposition  of  cement  material  formed  by  the  cementoblasts  lying  within 
the  developing  pericementum  or  wall  of  the  tooth-follicle. 

Dentinification. — Calcification  of  the  dentin  begins  at  about  the  six- 
teenth week  of  intrauterine  existence  by  the  formation  of  a  tiny  cap  or 
layer  of  calcific  material  at  the  tips  of  the  incisors  and  cuspids  (Fig.  168), 
and  about  a  week  later  in  the  cusps  of  the  molars.  The  process  begins 
upon  the  surface  of  the  dentinal  bulb  or  papilla,  by  the  formation  of  layers 
or  laminae,  one  within  the  other,  the  size  of  the  papilla  gradually  de- 
creasing as  each  new  lamina  is  formed  until  it  reaches  the  size  prescribed 
for  it  by  nature. 

Some  time  before  the  beginning  of  the  process  of  calcification  of  the 
dentin  there  is  a  layer  of  cells  developed  upon  the  surface  of  the  papilla, 
ovoid  in  form,  and  having  a  long  process  upon  the  end,  which  points 
towards  the  enamel-organ  (Fig.  169).  These  cells  have  already  been  men- 
tioned, and  were  termed  by  Waldeyer  the  odontoUasts  or  dentin-building 
cells. 

This  layer  of  cells  constitutes  the  memhrana  eboris  of  the  older  writers. 

The  form  of  the  odontoblasts  varies  considerably  at  dififerent  periods  of 
the  evolution  of  the  dentin.  In  the  early  stage,  just  prior  to  the  commence- 
ment of  the  process  of  calcification,  the  cells  are  generally  ovoid  and  have 


Enamel 


Dentin 


Fig.  163. — Vertical  section  of  enamel  and  dentin,  showing  interglobular  spaces,     y^  110. 


Lacunae 


1         ^^=^>rfs-    ^        ^    > 

«.    "*    t    •_  -Vs-  ir-*"«  -^  V  \ 

^.  *         J  ■^      r  ^        '  •.  my^"        r        *■       ^ 


Dentin 


'  Interglobular 


•'     a     spaces,  or 

*    "    granular  layer 
<'■      ■*  i)f  Tomes 


Fig.  164. — Transverse  section  of  dentin  and  cementum.    X  97. 


Enamel-rods, 

showing 

interprismatic 

substance 


Incremental 

ines 


Fig.  165.— Oblique  section  of  enamel  and  dentin,  showing  incremental  lines.     (V.  A.  Latham.)     X  500. 


Commencing 

formation  of 

the  root  by 

lengthening  of 

the  pul] 


Commencing 
formation  of 
tlie  root  by 
engtheningof 
the  pulp 


Fig.  106.— Vertical  section  of  face  of  human  embryo,  showing  the  beginning  of  the  formation  of  the  roots 

of  the  teeth.     (V.  A.  Latham.)     X  7. 


Root 

begiiiniii}< 

to  form 

Blood-vessels 

and  nerves 


Blood-vessels 
and  nerves 


Fig.  IG".— Section  of  human  lower  jaw,  shovi'ing  blood-vessels  and  nerves  at  base  of  the  tooth-follicle,  and  the 
beginning  of  the  formation  of  the  root.     (V.  A.  Latham.)     >,;  9. 


Enamel 


Dentin 


Dental  papilla 


I 


Fig.  168.— Vertical  section  of  developing  human   cuspid,  showing  early  stage  of  calcification.     (V.  A.  Latham.) 

X  lUO. 


Fig.  169. — Teased  section  of  developing  human  molar,  showing  the  odontohlasts  and  their  processes.     (V.  A.  Latham.) 

X  1000. 


^ 


Fibril  cell 


Truncated  odon- 
toblasts, showing 
spherule  of 
calcoglobulin 


Fig.  170.— Truncated  odontoblasts  and  libril  cells.     (R.  R.  Andrews.) 


HISTOLOGY    OF    THE   DENTAL   TISSUES.  49 

a  sino-le  r^rocess  but  during  the  active  stage  of  development  the  cells  are 
LaSCTor  truncated  at  the  end  directed  towards  the  forming  dentin 
m.  170)  During  this  period  the  odontoblasts  often  present  two  or  more 
processes  •  Boll  has  counted  no  less  than  six,  proceeding  from  a  smg  e  celL 
Each  cell  possesses  a  single  ovoid  nucleus,  which  is  located  in  the  end  of 
the  cell  nearest  to  the  dentinal  papilla  (Fig.  171).  The  nucleus  is  some- 
times pointed  at  the  extremity  nearest  the  forming  f^^^\^-  ^  ^h^  l^.^f  ^^f^ 
the  ceil  is  finely  granular,  and  Waldeyer  and  Boll  both  found  the  eel 
destitute  of  any  semblance  of  membrane.  The  processes  of  the  cells  pass 
into  the  dentinal  tubuli,  and  constitute  the  dentinal  fibrils. 

Stowell  (1887)  says  there  are  three  separate  forms  of  processes  arising 
from  each  odontoblast:  first,  those  that  unite  it  to  its  fellow  ;  second, 
those  by  which  it  forms  its  attachment  to  the  connective-tissue  cells  of  the 
pulp  proper  ;  and  third,  those  that  pass  into  the  dentinal  tubules,  the 
dentinal  fibrils,  the  latter  as  they  approach  the  periphery  of  the  dentin 
branch  and  finally  unite  with  the  cells  of  the  granular  layer  and  the 

cementoblasts.  v^i  „„<-<. 

After  the  active  stage  of  dentin  formation  has  passed,  the  odontoblasts 
again  resume  their  original  ovoid  form,  tapering  off  to  the  dentinal  process. 

Several  theories,  more  or  less  divergent,  have  from  time  to  time  been 
advanced  as  to  the  process  by  which  the  dentin  was  developed  the  mam 
point  in  controversy  being  the  part  played  by  the  odontoblasts  in  this 

^"^^Waldeyer,  Frey,  Boll,  Beale,  and  others  support  the  theory  that  the 
dentinal  fibrils,  the  sheaths  of  I^eumann  and  the  matrix  surrounding  them, 
are  formed  from  the  odontoblasts  by  a  metamorphosis  of  these  cells,  these 
structures  representing  three  stages  in  the  conversion  of  the  same  sub- 
stance. Beale  expresses  it  as  j)rotoplasm-t^e  dentinal  fibrils ;  formed 
material -the  dentinal  sheaths  ;  calcified  formed  material, -the  matrix,  the 
completed,  fullv  calcified  tissue. 

Yon  Ebner  has  discovered  the  existence  of  a  delicate  fibrillar  structure 
in  both  bone  and  dentin,  and  although  von  Ebner  and  Eose  both  believe 
that  the  whole  of  the  dentin  is  derived  from  the  odontoblasts,  they  say  their 
axial  portions  persist  as  the  dentinal  fibrils,  while  their  outer  portions  are 
metamorphosed  into  a  delicate  fibrillar  gelatinous  tissue,  a  sort  of  connec- 
tive tissue,  which  forms  the  matrix  and  receives  the  deposition  of  the  lime- 

Tomes  says  upon  this  question,  "The  close  relation  of  these  cells  to 
the  dentin,  their  change  in  form  according  as  dentin-building  was  or  was 
not  actively  «-oing  on,  their  resemblance  in  position  and  apparent  consist- 
ence to  osteoblasts,  and  the  absence  of  any  other  of  the  large  cells  which 
we  associate  elsewhere  with  elaboration  of  special  products,  would  natu- 
rally lead  to  the  inference  that  they  were  the  chief  factors  in  the  segrega- 
tion of  lime-salts  and  their  incorporation  in  the  dentin." 

Andrews  (1887)  called  attention  to  pear-shaped  cells,  which  he  termed 
"  deniM.  corpuscles,^'  lying  between  the  square-end  odontoblasts  so  uniformly 
present  during  the  active  stage  of  dentin  formation  (Fig.  172). 

The  odontoblasts  he  considers  as  simply  matrix  formers,  having  nothing 

4 


50  OPERATIVE   DENTISTRY. 

whatever  to  do  with  the  formation  of  the  dentinal  fibrils,  as  they  are  mem- 
braneless  masses  of  protoj)lasm,  while  the  pear-shaped  cells — '^dentin  cor- 
puscles"— form  the  dentinal  fibrils  by  the  elongation  of  their  processes, 
and  which  also  possess  the  important  function  of  nourishing  the  dentin 
matrix. 

Mr.  Mummery,  in  following  still  farther  the  investigations  of  von  Ebner, 
noted  the  appearance  of  connective-tissue  fibres,  or  bundles  of  fibres,  just 
in  advance  of  the  main  line  of  calcification,  which  had  not  been  derived 
from  the  odontoblast,  but  from  the  connective-tissue  cells  of  the  dentin 
papilla.  He  discovered  further,  in  young  developing  teeth,  by  the  aid  of 
Koch's  method  of  preparing  sections,  as  modified  by  Weil,  the  i^reseuce  of 
a  distinct  reticulum  of  fine  connective-tissue  fibres,  which  passed  in  bun- 
dles between  the  odontoblasts  and  enveloped  them.  Within  this  reticulum 
he  believes  the  calcium  salts  are  deposited  for  the  building  of  the  dentin 
matrix.  He  also  found  other  cells  than  the  odontoblasts  applied  to  the 
connective-tissue  fibres,  both  in  man  and  in  fish,  which  recall  the  cells 
attached  to  the  osteogenetic  fibres  of  bone. 

In  view  of  these  discoveries  it  would  seem  that  the  process  of  calcifica- 
tion of  dentin  is  more  nearly  like  that  of  bone  than  has  been  previously 
supposed,  and  if  Mr.  Mummery  is  right,  the  question  very  naturally  arises 
as  to  the  actual  part  taken  by  the  odontoblasts  in  the  formation  of  the  den- 
tin. It  would  seem,  however,  that  the  fact  is  fairly  well  established  that 
the  odontoblasts  form  the  dentinal  fibrils  by  the  elongation  of  their  pro- 
cesses, and  that  they  are  the  active  agents  in  the  development  of  the  dental 
tubuli  ;  but  whether  the  odontoblasts  or  the  cells  of  Mummery  superintend 
the  elaboration  and  deposition  of  the  calcific  material  to  form  the  dentin 
is  a  matter  of  doubt,  and  further  investigation  will  be  necessary  before  the 
question  can  be  settled. 

Andrews,  in  speaking  of  the  odontoblasts  and  the  jjear-shaped  cells 
described  by  Mummery,  says,  ' '  The  odontoblasts  are  masses  of  protoplasm, 
without  membranes,  and  are  at  a  certain  stage  of  growth  square  and  abrupt 
against  the  matrix.  It  is  an  easy  matter  to  find  among  them,  and  immedi- 
ately adjacent,  large  numbers  of  pear-shai^ed  cells,  tapering  into  the  denti- 
nal fibril.  The  odontoblasts,  when  calcification  is  active,  are  scarcely  more 
than  masses  of  protoplasm,  filled  with  minute  globules.  The  fibrils  which 
api^ear  to  come  from  them  are  described  by  Tomes  under  three  divisions, 
— viz.,  "pulp,  lateral,  and  dentin  processes,^ ^  which  originate  probably  from 
a  fibril-forming  cell.  These  pass  through  the  soft  substance  of  the  odonto- 
blasts (protoplasm),  and  seem  to  be  a  part  of  them,  but  in  fresh,  young 
sections  the  so-called  processes  move  in  the  substance  of  the  odontoblasts 
by  pressure  of  the  cover-glass,  and  the  fibril  may  be  traced  to  a  pear-shaped 
cell  beyond.  There  will  usually  be  found  as  many  processes  going  out 
from  the  sides  and  ends  of  the  odontoblasts  towards  the  pulp  as  there  are 
going  into  the  matrix  from  the  dentin  end  of  the  cell.  In  cross-sections 
of  the  odontoblasts,  delicate,  light  spots  are  seen  in  the  substance,  which 
are  x^robably  the  cut  fibres.  When  the  layer  of  odontoblasts  is  teased 
away  from  the  forming  dentin,  fibrils  are  seen  bridging  the  gap,  apparently 
off-shoots  from  the  odontoblasts  ;  but  on  careful  examination  there  will 


stellate  reticulum 


Ameloblastic 
layer 


Formed  enamel 


Formed  dentin 


Odontoblastic 
layer 


Dental  papillse 


Truncated  ends 
of  odontoblasts 


Fig.  171. — Section  of  tooth-follicle  (human),  showing  the  nuclei  of  the  odontoblasts  and  of  the  ameloblasts, 
and  the  truncated  ends  of  these  cells.     (V.  C.  Latham.)     X  325. 


Fig.  172.— Odontoblasts,  showing  truncated  cells  and  pear-shaped  bodies  lying  between  the  dentin  corpuscles. 

(R.  R.  Andrews.) 


Lacunpe  and  '^1?^*?^ 
canaliculi 


Haversian 


Fig.  17r).— Bone,  showing  Haversian  system,  lacunse,  and  canaliculi.     X  60. 


V  '\  \ 


^^^":r^*«> 


Fig  174  —Transverse  section  of  human  femur,  mature  bone.    X  bO. 


HISTOLOGY    OF    THE    DENTAL    TISSUES.  51 

usually  be  found  a  decided  line  of  demarcation  across  the  fibre  at  tlie  point 
where  it  meets  the  square  end  of  the  odontoblast.  This  line  seems  to  show 
that  the  fibril  was  not  continuous  with  the  x>rotoplas.m  of  the  cell.  Other 
sections  which  have  been  separated  by  teasing,  show  odontoblasts  having 
their  side  masses  of  protoiDlasm  drawn  away  from  the  fibril  which  appar- 
ently has  run  through  it.  Some  of  this  protoplasm  is  left  upon  the  fibril, 
giving  it  a  ragged  appearance  as  it  passes  from  a  canal  in  the  matrix  across 
to  the  separated  pulp-tissue,  bridging  the  gap. 

The  pear-shaped  cell  has  perhaps  a  more  important  function  than  the 
odontoblast  i^roper.  It  is  to  supply  the  life  and  nourishment  to  the  whole 
of  the  calcified  matrix,  as  the  bone-corpuscle  within  its  "  lacuna  supplies 
life  and  nourishment  to  bone  and  cementum." 

One  of  the  strongest  arguments,  however,  in  support  of  the  older 
theory  that  the  odontoblasts  elaborate  or  secrete  the  calcium  salts  and 
superintend  the  deposition  of  this  material  in  the  formation  of  the  dentin 
matrix,  is  the  fact  that  calcosfsherites  of  different  sizes  are  found  in  these 
cells  during  the  active  stage  of  calcification. 

Eobin  and  Magitot  noted  the  presence  of  globular  spherical  forms — ■ 
calcospherites — in  the  young  pulps  of  human  teeth.  Henle  also  discovered 
them  in  the  young  tooth-]3ulps  of  the  herbivora,  as  did  also  Robin  and 
Magitot.     . 

In  the  early  history  of  the  dentinal  papilla,  just  before  the  beginning 
of  calcification,  numerous  globular,  glistening  bodies — calcospherites — are 
to  be  seen  in  the  papilla  and  within  the  odontoblasts,  but  most  abundantly 
upon  the  surface  of  the  papilla  next  to  the  inner  tunic  of  the  enamel- 
organ,  just  where  the  first  layer  of  dentin  is  to  be  formed. 

The  calcospherites  are  seen  to  collect  in  large  numbers  at  this  point, 
where  they  arrange  themselves  in  groups  and  coalesce  to  form  larger  glob- 
ules of  calcoglobulin,  as  already  described.  These  again  melt  together  to 
form  the  first  layer  of  dentin,  the  matrix  forming  around  the  processes  of 
the  odontoblasts,  which  recede  as  each  additional  layer  of  dentin  is  laid 
down,  the  processes  of  the  odontoblasts  elongating  to  accommodate  the 
increasing  thickness  of  the  dentin  matrix. 

AVhat  becomes  of  the  superabundance  of  odontoblasts  resulting  from 
the  continual  decrease  in  the  size  of  the  dentin  papilla  during  the  forma- 
tion of  the  dentin  is  a  question  that  the  author  does  not  remember  to  have 
seen  or  heard  discussed.  It  is  a  well-established  fact  that,  as  a  rule,  cells 
and  tissues  which  have  performed  their  functions,  and  for  which  nature 
has  no  further  use,  either  atrophy  or  disintegrate,  are  resolved  into  their 
original  elements,  and  are  then  absorbed.  This  may  be  the  process  by 
which  the  used-up  cells  are  removed  in  the  formative  pulp.  But  in  seek- 
ing an  explanation  of  the  modus  operandi  by  which  the  tubules  of  the 
dentin  become  branched,  it  has  occurred  to  the  author  that  certain  of  the 
odontoblasts  may  coalesce  from  time  to  time  as  the  decrease  in  the  size  of 
the  papilla  makes  it  necessary  for  their  numbers  to  be  lessened,  thus  form- 
ing branching  dentinal  processes  around  which  the  dentin  matrix  is 
formed,  the  larger  fibril  or  main  trunk  representing  the  persistent  odonto- 
blast, while  the  branches  represent  the  fibrils  of  the  cells  which  have  been 


52  OPERATIVE    DENTISTRY. 

merged  into  the  persisting  cell.  This  would  also  explain  the  presence  of 
the  odontoblasts  having  multiple  processes  which  are  so  common  during 
the  active  stage  of  dentin  formation. 

The  presence  of  the  transverse  processes  which  seem  to  unite  the  odon- 
toblasts laterally  may  be  explained  by  the  recent  discovery  of  von  Ebner 
and  Mummery  of  a  connective-tissue  net- work  of  iibres  passing  between 
and  surrounding  the  odontoblasts,  and  just  in  advance  of  the  main  line  of 
calcification. 

CEMENTUM. 

Cementum,  or  crusta  petrosa,  is  a  specialized  product  of  specialized 
osteoblasts  or  bone-producing  cells,  the  cementoblasts. 

Mature  cementum,  chemically  and  physically,  is  very  little  different 
from  the  compact  tissue  of  bone,  with  the  exception  that  it  is  generally 
devoid  of  Haversian  canals.  Figs.  173  and  174  show  the  structure  of  mature 
bone. 

Cementum  is  the  external  covering  of  the  roots  of  the  teeth.  In  many 
animals  it  also  forms  a  part  of  the  covering  of  the  crown,  being  associated 
with  the  enamel  in  separate  vertical  laminae. 

The  cementum  begins  at  the  neck  of  the  tooth,  at  the  free  margin  of 
the  enamel,  in  a  thin  layer  (Fig.  175),  and  gradually  increases  in  thickness 
towards  the  a^e:^  of  the  root  (Figs.  176  and  177).  In  teeth  with  roots 
closely  associated  the  cementum  often  extends  from  one  root  to  the  other, 
resulting  in  a  firm  osseous  union. 

The  cementum  is  thicker  in  adult  life  than  in  childhood,  and  in  aged 
people  it  is  thicker  than  in  adult  life.  Black  thinks  it  grows  at  intervals 
during  the  life  of  the  individual. 

Histologically  it  is  composed  of  a  matrix  consisting  of  a  gelatinous  sub- 
stance combined  with  the  salts  of  lime.  Within  the  matrix  are  numerous 
little  hollow  spaces,  the  lacunae,  filled  with  protoplasmic  substance,  and 
from  which  branch  in  all  directions  many  minute  processes,  the  canaliculi  ; 
these  often  anastomose  with  neighboring  canaliculi  and  with  the  inter- 
granular  layer  (Fig.  178). 

The  matrix  is  composed  of  collagenous  fibrils  in  fine  or  coarse  bundles, 
combined  with  calcium  salts,  and  permeated  by  vascular  canals  in  the 
thicker  portions  near  the  apex  of  the  root.  These  vascular  canals  corre- 
spond to  the  Haversian  canals  of  bone.  Like  bone,  when  boiled  it  yields 
gelatin,  and  when  decalcified  it  retains  its  form.  At  times  it  appears  to 
be  structureless ;  at  others  finely  granular  or  interspersed  with  small 
globules  (Tomes). 

The  matrix  is  laminated  in  structure,  the  incremental  lines  running 
parallel  to  the  long  axis  of  the  tooth  ;  but,  although  the  cementum  is  thin 
at  the  cervix  and  thick  at  the  apex,  the  number  of  lamellae  is  about  the 
same  in  all  parts  of  the  tissue. 

The  lacunas  in  dried  sections  are  irregular  cavities  with  their  long  axis 
corresponding  to  the  long  axis  of  the  tooth.  The  processes  are  given  off 
most  frequently  at  right  angles  to  the  direction  of  the  lamellae,  and  most 
abundantly  upon  that  side  towards  the  exterior  surface  of  the  root.  The 
size  and  form  of  the  lacunae  in  cementum  are  very  variable,  while  the 


Fig,  175.— Transverse  section  of  human  cuspid,  at  cervix,     x  150. 


Enamel 


Dentin 
I'lilp-cavity 


Fig.  176.— Longitudinal  section  of  young  cuspid.  Fig.  177.— Longitudinal  section  of  young  molar. 


Fig.  178.— Transverse  section  of  apex  of  human  molar.    X  OT 


Fig.  179.  — LougiiLi.liual  ^tcLiuu  oi  lout  of  tooth  and  dheoUis,  showing  tissues  of  root  and  alveolus  iw  situ. 
(F.  B.  Noyes.)  X  SO.  D,  dentin  ;  C,  C,  oementum  ;  F,  fibres  passing  over  edge  of  process  to  outer  layer  of 
periosteum  ;  F',  fibres  passing  to  bone  (Sliarpey's  fibres). 


Alveolar  process 


Cancellus 


J 


'•"4- 


^     ^\  '  :  ' ''  '•  ^  ■  ■  ^-    - ' 


C'i 


Sharpey's  fibres 


Pericementum 


Alveolar  process 


\)iff^ 


('ancellus  i- 


>       ,>     \ 


^   / 


Fig.  180. — Vertical  section  of  human  alveolar  process  and  cuspid  tooth  in  silu.     (V.  A.  Lathaai.)     X  100. 


Fig.  ISl.— Developing  bone  from  human  scapula.     (V.A.Latham.)      •   .')0. 


HISTOLOGY    OF    THE    DENTAL    TISSUES.  53 

number  and  length  of  their  processes  are  excessive  when  compared  with 
bone. 

The  lacunae  are  formed  by  cementoblasts  or  nests  of  cementoblasts, 
which  have  been  encapsuled  during  the  process  of  calcification,  but  which 
have  maintained  their  individuality.  These  are  sometimes  termed  cement- 
corpuscles. 

81iarp€y''s  fibres  are  found  in  the  cementum,  having  the  appearance  of 
rods  which  run  through  its  substance.  They  are  composed  of  connective- 
tissue  fibres,  and  form  the  medium  of  connection  between  the  alveolo-dental 
membrane,  or  pericementum,  and  the  cementum.  Figs.  179  and  180  show 
Sharpey's  fibres  in  the  alveolar  process. 

The  dentin  and  the  cementum  are  inseparably  connected  through 
the  medium  of  the  granular  layer  of  the  dentin,  the  fusion  of  the  two 
tissues  being  so  complete  that  the  line  of  union  is  often  difficult  or  well- 
nigh  impossible  to  make  out. 

CEMENTIFICATION. 

According  to  the  common  classification  adopted  by  writers  upon  ossifi- 
cation, the  methods  by  which  bone  is  formed  are  stated  as  follows :  1,  in- 
tracartilaginous  or  enchondral ;  2,  subperiosteal  f  and  3,  intramembranous  ; 
but  the  essential  nature  of  the  process  is  the  same  in  all. 

In  the  intracartilaginous  method  the  bone  is  first  formed  or  preformed 
in  cartilage  (Fig.  181) .  In  the  subperiosteal  the  bone  has  not  been  X3re- 
formed  by  the  cartilage,  but  the  tissue  in  which  the  bone  is  to  be  formed 
is  fibrous  and  vascular ;  osteoblasts  appear  along  the  bundles  of  fibres 
beneath  the  periosteum,  which  become  calcified,  and  bone  is  formed 
around  them  (Stedman)  by  the  deposition  of  calcoglobulin,  as  already  de- 
scribed. Many  of  the  fibrous  bundles  persist  in  the  formed  bone  as 
Sharpey's  fibres,  while  in  the  intramembranous  form  the  bone  is  devel- 
oped, as  in  the  cranial  bones,  from  a  preceding  membranous  structure. 
Sudduth  adds  a  fourth,  interstitial,  a  division  of  the  intramembranous 
group,  which  he  thinks  is  necessary  to  explain  the  method  by  which  the 
maxillsB  are  formed.  He  claims  that  osteoblasts  are  found  in  the  embry- 
onal tissue  of  the  future  maxillary  bones  "before  there  are  any  indications 
of  a  condensation  of  the  connective  tissue  into  a  membrane  such  as  is  found 
when  ossification  first  begins  in  the  skull-cap.  A  few  osteoblasts,  inde- 
pendent of  the  influence  of  either  membrane  or  periosteum,  arrange  them- 
selves in  groups  here  and  there.  These  groups  are  the  points  of  ossifica- 
tion, and  from  them  the  process  extends  as  the  jaw  develops."  The  bone 
formed  in  this  manner  i^  provisional  bone,  and  is  later  removed  by  internal 
resorption,  as  is  the  case  with  all  foetal  bone,  and  replaced  by  a  permanent 
bone  formation. 

Cementification  is  a  slightly  modified  form  of  subperiosteal  ossification. 
"VYe  have  seen  in  our  study  of  the  origin  and  development  of  the  teeth  that 
the  enamel-organ  and  the  dentin  bulb  were  enclosed  within  a  sac  or  follicle. 

Calcification  of  the  enamel  and  dentin  has  progressed  within  this 
follicle,  but  the  walls  of  the  follicle  have  taken  no  part  in  the  process.  In 
the  formation  of  the  root  the  follicle  takes  an  active  ]3art  by  becoming  the 


54 


OPERATIVE    DENTISTRY 


cement  organ.  The  walls  of  the  follicle  are  composed  of  two  layers.  The 
outer  layer  is  a  dense,  firm,  fibrous  structure,  while  the  inner  layer  is  thin, 
frail,  and  somewhat  transparent ;  both  are  supplied  with  a  rich  net- work 
of  blood-vessels. 

From  the  outer  layer  of  the  follicular  wall  the  alveolo-dental  perios- 
teum, or  pericementum,  is  develoi^ed,  while  from  the  inner  layer  are  formed 
the  cementoblasts,  which  are  speedily  converted  into  cementum. 

The  dentin  of  the  root  is  in  most  part  formed  during  the  passage  of  the 
crown  from  its  bony  crypt  and  eruption  through  the  gum.  The  process 
of  building  the  root  is  from  the  outer  circumference  towards  the  centre : 
the  diameter  of  the  root  is  thus  fixed  by  the  outer  layer  of  the  dentin, 
while  the  increase  in  length  is  by  extension.  The  formation  of  the 
cementum,  like  that  of  the  enamel,  is  from  within  outward ;  the  first 
layer  of  the  cementum  being  dex^osited  upon  the  outer  circumference  or 
periphery  of  the  dentin  of  the  root ;  upon  this  layer  is  deposited  another, 
and  so  on  until  the  typal  thickness  is  reached  and  the  cement-tissue  is 
completely  formed. 

The  following  table  by  Underwood  will  be  found  valuable  as  a  ready 
reference  of  the  composition  of  the  various  calcified  dental  tissues  and 
their  comparison  with  bone  : 

CHEMICAL   COMPOSITION   OF  THE   CALCIFIED    TISSUES   (APPROXIMATE 

TABLE). 


Adult 
Enamel. 

Infantile 
Enamel. 

Adult 
Dentin. 

Adult 
Cementum. 

Adult 
Bone. 

Organic  matter 

Per  cent. 
3.50 

88.00 
4.50 
2  00 

Per  cent. 

15.50 

75.50 

7.00 

9  no 

Per  cent. 

28.00 

64.50 

3.50 

2.00 

1.50 

Per  cent. 
32  00 

Per  cent. 

Calcium  phosphate 

57  00             51  00 

Calcium  carbonate 

7  00             n  50 

Calcium  fluoride 

2  00                2  00 

Magnesium  phosphate 

Other  salts 

1.50               1.50 
0  50              0  ^a 

1.50             .   1.50 
0  .'SO               n  ?in 

100.00 

100.00 

100.00 

100.00 

100.00 

It  will  be  seen  the  amount  of  organic  matter  varies  considerably  be- 
tween infancy  and  adult  life.  Galippe  (Journal  British  Dental  Association, 
1886,  p.  361)  has  a  very  exhaustive  paper  on  the  chemical  composition  of 
the  teeth. 

Hoppe-Seyler  has  found  in  the  enamel  of  the  new-born  child  as  much 
as  22.29  per  cent,  of  organic  matter,  9.71  per  cent,  in  the  young  pig,  and 
in  the  fossil  rhinoceros  3.16  per  cent.  Bibra  gives  two  per  cent,  of  organic 
matter  in  the  adult  male  and  five  per  cent,  in  the  adult  female. 


js^asmyth's  membrane. 

The  origin  and  function  of  IS'asmyth's  membrane  has  famished  matter 
for  a  considerable  difierence  of  opinion  and  much  speculation.  Tomes 
and  Magitot  regard  it  as  a  thin  covering  of  cementum,  as  it  is  similar  to 
and  continuous  with  the  cementum  covering  the  root,  lacunae  being  foand 
in  its  substance. 


Outer  layer 
of  columnar 
cells 


Inner  layer 
of  columnar 
cells 


Knamel 


-Vertical  section  of  human  enamel  and  Nasmyth's  membrane,  sViowing  the  latter  to  be  composed 
of  what  appears  to  he  two  layers  of  columnar  epithelial  cells.     (V.  A.  Latham.)     X  250. 


■■1 

^^HHiPl^>^^^S^Ii^^^^^^^^^^l 

^^^^^^^^^H^l 

■p^pv^^      .   .     ' '^^IH^^^^^^^H 

BR^     -  #'v    »                          ^'^fli^^^^^^^^^H 

^''                    «»*         .4.    nK^^^^^^^^^^^B 

^^^^^^^^HHpi^ 

r;     *     •,  «    ^                                ^^l^^^^^l 

^^^^^^B^ 

.*^    •*  *  i                                  '  *    ■  ^H^H^B 

•    >r           •'",■•4-    -              •    •          ,         '"-                                 ™ 

•  » » • 

■  't   * 

•*'  * 

«v 

-  ,  ^^r  ^    •»'-**'*- *'^*.  •  r  »^ " 

*  _ 

^^S^                  "*       ^ 

"     4-    -  ^_^              , 

^^   *  ^  '•  ♦"    '^ 

* '..  ♦      "  *  •  ^>  .         J 

*    ,    **  «'^Jh^| 

" 

-•»  '        ^  >»■                                      ^tdi^^H 

Mm. 

^MHM 

H^^^^g^             ' 

Bj|liM|||to»  . 

i*"^  ^^fll^^^^^H 

nnn 

Fig.  183. — Section  of  normal  pnli>-ti^~u(  ,  sluiwiiii;  its  variniis  forms  of  cells  and  the  hair-like  processes. 

(V.  A.  Latham.)      ■;  143. 


Fia.  184. — Section  of  normal  puIp-tissue,  b.ho\ving  odontoblastic  layer.     (V.  A.  Latham.)     x  145. 


)  > 


\  '^  :  1 


Fig.   185. — ^Injected  blood-vessels  of  the 
pulp.     (After  Stowell.) 


Fig.  186.— Vertical  section  of  developing  teeth  of  kitten.    Injected 
to  show  blood-supply  of  pulp.     (V.  A.  Latham.)    )<  10. 


Pig.  187.- 


-Vertical  section  of  human  deciduous  molar  in  sthi. 
{\ .  A.  Latham.)     >; 


Injected  to  sliow  blood-supply  of  the  pulp. 


HISTOLOGY    OF    THE    DENTAL    TISSUES.  55 

Huxley,  Kolliker,  Waldeyer,  and  Eose  liave  each  maintained  that  the 
cuticula  dentis  was  derived  from  the  epithelium  of  the  enamel  organ, 
,  "Waldeyer  stating  that  it  was  the  product  of  the  outer  tunic  of  the  enamel 
organ. 

Paul  (1896)  has  shown  that  the  membrane  was  composed  of  flat  epi- 
thelial cells.  These  could  come  from  no  other  source  than  some  i^art  of 
the  enamel-organ,  probably  from  the  outer  tunic.  Paul  suggests  that  its 
function  is  to  protect  the  enamel  from  the  action  of  acids.  C.  S.  Tomes, 
who  formerly  held  the  view  of  his  father,  now  agrees  substantially  with 
Paul.  He  says,  ''  The  more  recent  investigations  of  Dr.  Paul  have  thrown 
a  fresh  light  uidou  the  matter,  and  have  shown  that  the  points  upon  whicli 
I  chiefly  relied  are  susceptible  of  quite  a  different  explanation." 

Sudduth  thinks  it  is  derived  from  a  metamorjihosis  of  the  ameloblastic 
layer,  the  prismatic  cells  of  which  assume  a  horizontal  direction.  Mrs. 
Emily  ^unn  Whitman  has  noted  these  changes  in  studying  the  develop- 
ment of  the  teeth  of  the  rat  and  the  rabbit,  and  has  ' '  traced  the  gradual 
transition  of  the  enamel-rods  into  a  perfectly  homogeneous  membrane,  the 
cylindrical  cells  growing  shorter  and  shorter  as  they  approached  the  sur- 
face of  the  crown,  until,  instead  of  being  columnar,  they  are  almost  square, 
and  finally  flattened,  while  at  the  last  the  outlines  of  the  cells  quite  disap- 
pear, and  there  is  left  a  perfectly  homogeneous  membrane." 

From  the  appearances  in  the  illustration  (Fig.  182)  of  a  vertical  section 
of  the  enamel  and  I'J'asmyth's  membrane,  it  would  seem  that  it  was  un- 
doubtedly formed  from  the  outer  tunic  of  the  enamel-organ,  and  that  the 
columnar  character  of  the  cells  was  maintained  in  the  formation  of  the  mem- 
brane. It  will  be  noticed  by  a  reference  to  the  illustration  that  in  this  case 
the  membrane  is  composed  of  two  layers  of  columnar  cells  superimposed 
one  above  the  other.  The  section  illustrated  was  taken  from  a  depression 
in  the  surface  of  the  enamel  where  it  would  be  protected  from  wear.  This 
membrane,  from  its  resistance  to  acids  and  alkalies,  putrefaction,  boiling, 
etc.,  would  seem  to  be  composed  of  the  same  substance  as  the  matrix  of 
dentin. 

THE   TOOTH-PULP. 

Thepulpa  dentis,  the  organ  occupying  the  central  cavity  or  pulp-cham- 
ber of  a  mature  tooth,  is  the  remnant  of  the  formative  organ  of  the  den- 
tinal tissue,  and  the  source  of  the  nutrition  and  nerve  supply  of  the  fully 
formed  dentin. 

The  tooth-pulxD,  which  is  often  erroneously  termed  the  "nerve,"  is 
composed  of  a  very  delicate  connective  tissue,  nucleated  cells,  blood-ves- 
sels, and  nerves,  while  in  general  outline  it  corresponds  very  closely  to  the 
exterior  form  of  the  tooth.  The  matrix,  or  basis  substance  of  the  pulp,  is 
composed  largely  of  a  kind  of  undeveloped  soft  connective  tissue,  possibly 
belonging  to  the  mucous  or  gelatinous  species  containing  numerous  cellular 
elements  (Ziegler)  of  rounded,  oval,  and  spindle  forms,  with  slender,  hair- 
like processes  (Fig.  183). 

The  interspaces  between  the  fibres  are  large  and  filled  with  a  jelly-like 
material,  which  gives  it  an  appearance  common  to  many  forms  of  embry- 
onic tissue. 


56  operativp:  dentistry. 

The  cells  of  the  pulp  are  fairly  abundant,  but  not  sufficiently  numerous 
to  form  a  tissue  of  themselves  ;  they  are  found  scattered  throughout  the 
matrix,  embedded  in  the  jelly-like  material  within  the  interspaces,  and 
upon  the  perij)hery. 

The  form  and  distribution  of  the  cells  varies  very  considerably  in 
different  parts  of  the  pulp.  In  the  deeper  coronal  portions  the  cells  are 
not  numerous  ;  they  may  be  spheroidal,  oval,  or  spindle-shaped,  and  have 
no  definite  order  or  relations  to  each  other,  while  in  that  portion  within 
the  root-canals  the  cells  are  arra>nged  parallel  with  each  other  and  with 
the  root.  As  the  periphery  of  the  pulp  is  approached  the  arrangement  of 
the  cells  becomes  more  orderly,  many  cells  having  three  or  more  processes 
are  seen,  some  extending  towards  the  pulp,  while  the  others  are  directed 
towards  the  dentin  and  pass  between  the  odontoblasts.  The  last-named 
cells — the  odontoblasts — are  arranged  in  a  definite  order,  side  by  side,  in  a 
single  layer  over  the  whole  periphery  of  the  pulp,  covering  it  as  with  a 
delicate  membrane  or  epithelium  (Fig.  184).  The  odontoblasts  are  fur- 
nished with  three  sets  of  processes,  as  already  described,  one  set  con- 
necting it  with  its  fellows,  another  with  the  connective  tissue  of  the  pulp 
proper,  and  a  third  which  pass  into  the  dentinal  tubuli. 

The  blood-vessels  of  the  pulp  are  numerous;  three  or  more  arteries 
often  enter  at  the  apical  foramen,  divide  into  innumerable  branches,  and 
form  an  extensive  net- work,  as  shown  in  Fig.  185,  terminating  in  a  rich 
capillary  plexus  beneath  the  layer  of  odontoblastic  cells. 
Fig.  189.  rpj^jg  ^g  ^^^^1  illustrated  in  Fig.  186,  made  from  a  section  of 
the  jaw  and  developing  teeth  of  a  kitten  injected  for  this 
purpose.  The  veins  are  also  numerous  and  somewhat  larger 
than  the  arteries.  The  blood-supply,  however,  is  better 
shown  in  Fig.  187,  which  is  made  from  an  injected  human 
decidulous  molar.  They  form  frequent  anastomoses  near 
the  surface,  as  shown  in  Fig.  188,  which  is  also  made  from 
an  injected  specimen.  Lymphatics  have  never  been  demon- 
strated in  the  pulp. 

The  nerves  of  the  pulp  enter  the  apical  foramen  either 
in  a  simple  large  trunk  or  by  several  smaller  ones.  They 
pursue  a  parallel  course,  giving  off  but  few  branches  until 
Nerves  of  dental  ^]^g  pulp -chamber  is  reached,  when  they  divide  into  numer- 
ous branches,  going  in  all  directions,  and  forming  a  minute 
net-work  just  beneath  the  odontoblasts,  where  they  end  in  non-meduUated 
fibres  (Fig.  189).  Many  terminal  fibres  pass  between  the  odontoblasts  to 
the  dentin  ;  but  the  final  distribution  of  the  fibres  has  never  been  satisfac- 
torily demonstrated. 

THE   PEEIDENTAL   MEMBRANE. 

The  peridental  membrane,  pericementum,  or  the  alveolo- dental  perios- 
teum (Fig.  190),  is  a  fibrous  connective-tissue  structure  which  covers  or 
invests  the  root  of  the  tooth  from  the  cervix  to  the  apical  foramen  (Fig. 
191),  just  as  the  periosteum  invests  the  bones  (Fig.  192)  and  lines  the 
walls  of  the  alveoli,  having  few  elastic  fibres,  and  richly  supplied  with 


Fig.  188. — Section  of  injected  dental  ])uli).     ; 


Pericementum 


-  Alveolar  process 


Pericementum 


Alveolar  j)rocess 


Fig.  190. — Section  of  jaw  of  field-mouse,  showing  pericementum  and  alveolar  process  between  the  teeth. 

(V.A.Latham.)     X  100. 


Nerve  ' 


Blood- 
vessels 


Odonto- 
blastic 
layer 


Fui.  ]yi.— Transverse  section  throug-h  pulp-chamljer  of  human  cuspid  tooth. 


Ulna 


Periosteum 


Fig.  192.— Transverse  section  of  forearm  of  a  child,  showing  jjeriosteum  surrounding  the  bones.    X  13 


Peridental 
membrane 


Fi<i.  ly:-;. — Transverse  section  throu^'h  rcxitsuf  foriniiiLc  tuntlidf  ficlil-nKiu^ 
dipping  in  between  the  roots.     (V.  A.  Latham.) 


hiiwiiiu:  peridental  membrane 
176. 


Develop- 
ing bone 


Fig.  194.— Transverse  section  of  developing  tooth  of  field-mouse  at  base  of  the  dentin  papilla;,  showing  peri- 
dental membrane.     (V.  A.  Latham.)     X  '5. 


Fig.  195. — Transverse  section  of  jaw  throuuh  al\  i-ular  i)rocess,  showing  tissues  of  root  and  alveolus  in  situ. 
(F.  B.  Noyes.)  X  30.  E,  epithelium  ;  F,  suhepithelial  connective  tissue ;  B,  point  where  pericementum  fibres 
are  lost  in  fibrous  mat  of  gum  ;  F',  fibres  extending  from  tooth  to  tooth  (Sharpey's  fibres) ;  P,  pulp. 


'f'fi 


,    ,, :^^\u- 


/ 


x9 


Fig.  196. — Longitudinal  section  of  root  of  tooth  in  situ,  showing  relation  of  the  tissues  and  Sharpey'S 
fibres  in  the  alveolar  process.  (F.  B.  Noyes.)  D.  dentin ;  N,  Nasmyth's  membrane ;  C,  C,  cementum  ;  J'', 
fibres  supporting  gingivus ;  F^,  fibres  joining  the  outer  layer  of  periosteum  over  the  alveolar  process 
(Sharpey'S  fibres)  ;  F-,  fibres  running  from  cementum  to  bone  ;  B,  bone  or  alveolar  process. 


Turning  under  of 

the  base  of  the 

enamel-organ 


Blood-vessels 
and  nerves 


Fig.  197.— Vertical  section  of  a  dental  follicle,  showing  the  blood-vessels  and  nerves  entering  at  the  base  of  the  follicle 
and  a  peculiar  turning  under  of  the  enamei  organ  at  the  base  of  the  dental  papillre.     (V.  A.  Latham.)     X  96- 


Fig.  198.— Section  of  pericementum  m  «7tt.  showing  epithelial  bodies.    (F.  B.  Noyes. ")     s  408.    D,  dentin;    C,  cementiim; 
Cb,  cementoblasts ;  Fb,  fibroblasts ;  E,  E,  E,  epithelial  structures. 


HISTOLOGY   OF    THE    DENTAL    TISSUES.  57 

vessels  and  nerves.     It  is  in  reality  periosteum,  slightly  modified  to  adapt 
it  to  its  environment  and  special  functions. 

The  peridental  membrane  is  derived  from  the  sacculus  of  the  dental 
follicle.  It  is  continuous  with  the  periosteum  of  the  alveolar  process,  and 
appears  to  be  a  reflection  of  this  membrane,  to  line  the  walls  of  the  alveoli 
and  invest  the  root  of  the  tooth.  Fig.  193  shows  the  membrane  at  an 
early  developmental  period  dipping  in  between  the  forming  roots  of  the 
tooth  of  a  field-mouse. 

The  dental  sacculus  is  composed  of  two  layers,  the  external  being  made 
up  of  a  fairly  dense  fibrous  connective-tissue  structure,  while  the  internal 
layer  is  rich  in  cellular  elements  and  retains  a  softer  and  more  embryonic 
character.  The  external  layer  upon  the  eruption  of  the  tooth  becomes  the 
jDcridental  membrane,  while  the  internal  layer  furnishes  the  cellular  ele- 
ments for  the  formation  of  the  cementum  (Fig.  194)  ;  in  other  words,  it 
becomes  the  cement  organ. 

The  pericementum  is  a  single  membrane  common  to  the  cementuui  and 
the  alveolar  wall.     There  is  no  evidence  whatever  of  a  double  membrane. 

The  j)eridental  membrane  of  a  mature  tooth  is  thickest  near  the  cervix 
and  at  the  apex  of  the  root.  The  general  direction  of  its  fibres  is  trans- 
verse ;  in  other  words,  they  run  through  the  thickness  of  the  membrane 
from  the  cementum  to  the  alveolar  wall  (Fig.  195).  The  attachment  of  the 
pericementum  is  increased  by  the  presence  of  bundles  of  fibres, — Sharpey's 
fibres, — which  penetrate  the  bone  upon  the  one  side  and  the  cementum 
upon  the  other  (Fig.  196),  but  in  general  the  membrane  is  more  strongly 
adherent  to  the  cementum  than  to  the  walls  of  the  alveolus.  Sharpey's 
fibres  are  found  most  abundant  at  the  cervix.  '■  •  They  are  white  connec- 
tive-tissue fibres,  the  ends  of  which  are  included  in  the  matrix  of  the  cemen- 
tum sufficiently  to  make  them  apparent  when  the  lime-salts  are  removed, 
but  when  both  are  calcified  they  cannot  be  demonstrated  except  in  cases 
where  there  is  imperfect  calcification  of  the  fibres"  (Black). 

The  functions  of  the  pericementum  are  fivefold, — viz.,  first,  by  its 
cementoblasts  to  form  the  cement-tissue  ;  second,  to  furnish  connection 
and  attachment  of  the  root  to  its  alveolus ;  third,  to  act  as  an  elastic 
cushion  or  bufi"er  between  the  root  and  the  alveolus,  thus  providing  against 
injury  from  the  severe  concussion  and  lateral  strain  incident  to  mastica- 
tion ;  fourth,  to  provide  nutrition  for  the  cementum  through  its  abundant 
vascular  supply  5  and  fifth,  to  give  sensation  to  the  cementum  and  the 
tactile  sense  to  the  tooth  through  its  plexus  of  nerves. 

The  blood-sujjjyly  of  the  pericementum  is  derived  from  two  sources,  the 
principal  one  being  the  main  artery  entering  the  deepest  point  of  the  alve- 
olus (Fig.  197).  This,  entering  the  thicker  portion  of  the  membrane  at 
the  aiDcx  of  the  root,  divides  into  several  branches,  one  or  more  of  which 
pass  through  the  membrane  and  enter  the  apical  foramen  to  suiDjDly  the 
pulj) ;  while  the  others  are  distributed  to  the  substance  of  the  pericemen- 
tum, and  through  their  capillaries  furnish  nutrition  to  the  cementum. 
Numerous  minute  branches  derived  from  the  blood-vessels  of  the  alveolus 
also  i^enetrate  the  membrane  and  freely  anastomose  with  the  vessels 
derived  from  the  apical  plexus. 


58  OPERATIVE    DENTISTRY. 

Wedl  says  the  vascular  supply  is  derived  from  three  sources  :  the  gums, 
the  vessels  of  the  bone,  and  the  vessels  destined  for  the  pulp  of  the  tooth, 
the  last  being  the  most  important. 

Black  has  recently  demonstrated  the  presence  of  certain  bodies,  of 
epithelial  structure  (Fig.  198),  which  from  their  form  and  location  he  is 
inclined  to  believe  are  lymph-glands  Ijang  within  the  iDcricementum ;  he 
describes  them  as  being  lobulatcd  in  form,  and  filled  with  lymphoid  cells. 
These  gland-like  bodies  are  beautifully  shown  in  the  accomx^anying  photo- 
micrographs (Figs.  199  and  200),  prepared  by  Professor  F.  B.  I^oyes,  of 
the  ISTorthwestern  University  Dental  School.  Black  was  unable,  however, 
to  fully  demonstrate  the  existence  of  a  duct  or  channel  leading  from  any 
of  the  glands. 

The  nerve-sui^ply  of  the  ]3ericementum  is  from  two  sources,  and  is  dis- 
tributed in  a  manner  similar  to  that  of  the  blood-supply.  The  principal 
•source  of  nerve-supply  is  from  the  dental  nerve  ;  a  single  branch  is  given 
off",  which  enters  the  alveolus  with  the  blood-vessels,  where  it  divides  into 
several  filaments,  a  portion  going  to  the  pulp  and  the  others  being  distrib- 
uted to  the  pericementum  ;  numerous  other  filaments  enter  the  membrane 
from  various  minute  channels  in  the  alveolar  walls  and  the  intervening 
seiDta  to  unite  with  those  derived  from  the  dental  nerve. 

The  vital  connection  of  the  human  tooth  with  the  living  organism  is 
very  intimate,  being  abundantly  supplied  with  blood-vessels  and  nerves, 
both  to  its  X3ulp  and  pericementum. 

Tomes,  referring  to  this,  says,  ''The  dentin  is  organically  connected 
with  the  pulp  by  the  dentinal  fibrils  ;  these  are  connected  with  the  soft 
cement- corpuscles,  which  again  are  brought  by  their  processes  into  inti- 
mate relation  with  similar  bodies  in  the  highly  vascular  periosteum,  so  that 
between  the  pulp  on  the  inside  and  the  periosteum  on  the  outside  there  is 
a  continuous  change  of  living  plasm." 

THE   GtTMS. 

The  gumSj  or  gingivce,  are  formed  of  a  layer  of  tough,  fibrous,  non-elastic, 
vascular  connective  tissue  (Fig.  201)  covering  the  alveolar  j)rocesses,  being 
closely  associated  with  the  periosteum,  the  fibres  of  which  intercommuni- 
cate, and  covered  with  the  common  mucous  membrane  of  the  mouth 
(Fig.  202).  It  unites  with  the  pericementum  at  the  cervix  of  the  tooth 
without  any  line  of  demarcation.  ISTumerous  papillae  are  present,  single 
and  compound.  The  gum-tissue  is  abundantly  supplied  with  blood-vessels, 
but  nerve -filaments  are  rarely  found.  Lobulated  glandular  structures  are 
to  be  seen  ;  these  are  the  glands  of  Serres  (Fig.  203). 

The  margins  of  the  gums  closely  invest  the  necks  of  the  teeth,  forming 
festoons  which  occupy  the  interapproximal  siJaces. 

The  epithelium  of  the  mucous  membrane  covering  the  gum  is  com- 
posed of  a  dense  laminee  of  tessellated  cells,  which  are  derived  from  the 
deeper  layer  of  columnar  cells, — the  rete  MalpigUi  (Fig.  204).  The  epi- 
thelium is  very  tough  and  hard.  This  fits  it  in  a  remarkable  degree  to 
withstand  the  severe  abrading  action  of  certain  forms  of  food  during  their 
mastication. 


Fig.  199. — Section  of  j>eridental  membrane,  showing  epithelial  bodies  or  glandular  .structures.    (F.  B.  Noyes.) 
X  "00.    J),  dentin  ;  C,  cementum;  C'6,  cemeiitoblasts ;  i?,  epithelial  bodies  :  F,  F,  white  fibres. 


Fic 


.  200. — Section  of  peridental  memhrane,  showing  epithelial  bodies  or  glandular  structures.    (F.  B.  Noyes.) 
X  900.    D,  dentin  ;  C,  cementum ;  Ch,  cementoblasts ;  E,  epithelial  bodies  ;  F,  white  fibres. 


Mucous  membrane 


Gum 


Periosteum 


Alveolar  process 


reric'cmeutum 


(  ementum 


Fig.  201.— Transverse  section  of  the  jaw  throusrh  the  mucous  membrane,  gum,  and  alveolar  process. 

(V.  A.  Lalham.)     X  00. 


Mucous  membrane  and  epithelium 


Bone 


Fig.  202  — Oljhque  sectiou  of  dental  follicle  and  mucous  membrane.     (V  A.  Laihaju.)      '  2G. 


Fig.  20o. — Glands  of  Serres.     X  50. 


Fig.  204.— Epithelial  layer  of  mucous  membrane  in  its  embryonic  stage.    A.  squamous  epithelial  cells; 

B,  columnar  cells — rete  Malpighii. 


OHAPTEE    IV. 

ERUPTION   OF   THE   TEETH. 

Definition. — The  i3rocess  by  which  the  teeth  advance  from  the  bony 
crypts,  in  which  they  have  undergone  the  calcification  of  their  crowns 
and  a  j^ortion  of  their  roots,  and  are  forced  through  the  gums. 

Synonymes. — Teething  ;  cutting  the  teeth  ;  dentition. 

Dentition  is  a  physiologic  process  having  no  counterpart  in  the  growth 
of  other  tissues.  Fig.  205  represents  a  tooth  in  the  process  of  eruption,  the 
nearest  approach  to  like  conditions  being  the  emergence  of  the  hair-sheaths 
and  the  nails.  In  this  use  of  the  term  dentition  it  will  be  understood  that 
it  has  no  reference  to  the  process  of  development  of  the  germs  of  the  teeth, 
but  refers  only  to  the  process  of  eruption.  Fig.  206,  made  from  a  section 
of  the  jaw  of  a  young  rabbit,  and  Fig.  207,  made  from  a  section  of  the 
foetal  jaw  of  a  field-mouse,  show  the  relation  of  the  i)rimary  and  secondary 
teeth  to  each  other  at  the  period  of  the  eruption  of  the  primarj^  teeth. 

The  process  of  dentition  is  divided  into  primary,  the  eruption  of  the 
deciduous  or  milk-teeth,  and  secondary,  the  eruption  of  the  permanent 
teeth. 

li^ormal  primary  or  deciduous  dentition  begins  between  the  fifth  and 
eighth  months  after  birth,  and  terminates  between  the  twenty-fourth  and 
thirty-second  months.  The  following  table  represents  the  average  period 
of  the  eruption  of  the  various  classes  of  teeth  which  constitute  the  tempo- 
rary denture : 

The  central  incisors from    5  to    8  months  after  birth. 

The  lateral  incisors from    7  to  10  months  after  birth. 

The  first  molars from  12  to  16  months  after  birth. 

The  cuspids from  14  to  20  months  after  birth. 

The  second  molars from  20  to  32  months  after  birth. 

The  inferior  teeth  usually  appear  a  few  weeks  in  advance  of  the  supe- 
rior. j!^o  general  rule  can  be  formulated  from  which,  however,  there  will 
not  be  marked  and  frequent  deviations.  The  variations  are  so  marked  in 
the  dates  of  the  eruption  of  the  teeth  that  no  two  authors  give  them  exactly 
alike.  Tubercular  and  syphilitic  children  erupt  their  teeth  very  early, 
while  in  rhachitic  children  the  process  begins  very  late. 

It  has  been  stated  that  Richard  Coeur  de  Lion  of  England  and  Louis 
XIY.  of  France  were  born  each  with  several  teeth. 

It  is  not  a  very  uncommon  occurrence  for  children  to  be  born  with 
teeth.  Haller,  in  his  ''Elements  of  Physiology,"  mentions  nineteen  cases 
of  children  that  were  born  with  one  or  more  teeth  fully  erupted. 

The  author  has  several  times  been  called  ui^on  to  remove  teeth  from  the 
mouths  of  newly  born  infants,  and  there  are  few  physicians  or  dentists  of 

59 


60  OPERATIVE    DENTISTRY. 

twenty  or  twenty-five  years'  practice  who  have  not  had  a  similar  expe- 
rience. 

Crump  reported  to  the  Virginia  Society  of  Dentists  a  case  of  full  denti- 
tion in  a  child  at  birth  (Pepper)  ;  while,  upon  the  other  hand,  the  teeth  are 
sometimes  entirely  suppressed. 

BoxaTli  and  Baumes  have  each  recorded  a  case  in  which  the  individual 
reached  old  age  without  a  single  tooth  ever  having  ap]Deared.  A  few  years 
ago  a  Eussian  family,  father  and  young  son,  were  on  exhibition  before 
medical  and  dental  societies  and  in  various  museums  under  the  name  of 
"dog-faced  men."  The  father  had  no  teeth  up  to  the  age  of  seventeen, 
then  four  teeth  appeared  in  the  lower  jaw  but  none  in  the  upper.  The  son 
had  four  lower  incisor  teeth  but  no  evidence  of  any  others.  The  jaws  of 
the  father,  who  was  a  strong  and  X30werfully  built  man,  were  no  larger 
than  those  of  his  little  son. 

The  Eruptive  Process. — The  modus  operandi  or  the  character  of  the 
agencies  by  which  the  teeth  are  stimulated  to  advance  from  their  bony 
crypts  and  emerge  through  the  gums  has  never  been  satisfactorily  demon- 
strated or  explained.  Several  views  have  been  advanced  to  account  for 
the  process,  but  they  are  all  open  to  serious  objections. 

The  first,  and  perhaps  the  oldest,  theory  is  that  the  tooth  is  impelled 
from  its  crypt  and  through  the  gum-tissue  by  mechanical  pressure  induced  hy 
the  growth  or  lengthening  of  the  root  from  additions  of  dentin  at  its  base. 

Several  strong  objections  can  be  raised  against  this  view  :  first,  teeth 
with  very  short  or  stunted  roots — roots  which  are  much  shorter  than  the 
distance  from  the  margin  of  the  gum  to  the  base  of  the  crypt — are  often 
erupted  ;  second,  deciduous  incisors  are  not  infrequently  found  erupted  at 
birth,  or  make  their  appearance  a  few  weeks  afterwards,  which  have  very 
little  or  no  roots  at  all,  the  crown  only  being  developed  ;  third,  a  tooth  in 
which  the  root  is  completely  developed  may  remain  buried  in  the  jaw  until 
past  middle  life,  and  then  make  its  appearance ;  fourth,  normal  teeth, 
particularly  the  superior  cuspids,  are  so  located  in  their  bony  crypts  that 
in  the  process  of  the  eruption  of  their  crowns  the  distance  travelled  greatly 
exceeds  in  amount  the  addition  made  to  the  length  of  the  root  during  the 
same  period. 

C.  S.  Tomes  says,*  "The  tooth  of  a  crocodile  moves  upward,  tooth- 
pulp  and  all,  obviously  impelled  by  something  different  from  mere  elonga- 
tion ;  and  my  own  researches  upon  the  development  and  succession  of 
reptilian  teeth  clearly  show  that  a  force  quite  independent  of  increase  in 
their  length  shifts  the  jposition  of  and  '  erujits'  successive  teeth." 

Another  theory  advanced  to  account  for  the  process  of  eruption  is  me- 
chanical pressure  induced  by  the  lengthening  of  the  dentinal  pap  illce  or  formative 
pidp.  The  principal  objection  to  this  view  is  the  improbability  that  the 
elongation  of  a  delicate  and  more  or  less  embryonic  structure  like  the 
formative  pulp  could  produce  a  sufficient  amount  of  pressure  upon  the 
tooth- crown  at  its  base  to  cause  resorption  of  the  overlying  bony  walls  of 
its  crypt  without  injury  to  its  own  structure,  or  causing  deflection  of  the 

*  Dental  Anatomy. 


Crown 


Bon 


Forming  root 


Fig.  205. — Vertical  section  of  the  jaw,  showing  forming  mot.     X  15. 


Perma- 
nent 
tooth - 
follicle 


Fig.  206.— Section  of  jaw  of  rabtut  >-h<)«  ma:  deciduous  tt  eth  and  follicles  of  peimanent  teeth  m  «i7i(  at  the 
period  of  the  eruption  of  the  primary  teeth.    ^    22. 


Fig.  207. — Lower  jaw  of  tetal  field-mouse.      <  80. 


Area  of  resorption 


Fig.  208.— Vertical  section  of  erupting  tooth  of  field-mouse,  showing  area  of  resorption  at  the  cusp  of  the  tooth.    X  C5 


ERUPTION    OF    THE    TEETH.  61 

apical  end,  and  thus  producing  crooked  roots,  which  is  by  no  means  a  gen- 
eral condition. 

Delabarre  suggested  that  the  advance  of  the  tooth  from  its  crypt  and 
its  passage  through  the  gum  was  effected  in  precisely  the  same  manner  as 
the  foetus  is  expelled  from  the  uterus.  He  regarded  the  sac,  which  he 
claimed  was  attached  above  to  the  gum  and  below  to  the  neck  of  the  tooth, 
as  the  active  agent  in  the  eruption  of  the  tooth,  induced  by  the  contrac- 
tion of  its  walls,  and  thus  the  crown  of  the  tooth  was  lifted  from  the  base 
of  the  follicle  and  ultimately  forced  through  the  uncapped  crypt  and  the 
gum. 

This  is  a  very  ingenious  explanation,  and  is  based  upon  the  supj^osition 
that  there  are  elastic  fibres  within  the  walls  of  the  sac. 

^N'asmyth  found  the  sac  to  be  composed  of  two  layers,  the  inner  lamina 
composed  of  a  layer  of  cells  loosely  arranged,  with  interspaces  equal  to 
one-half  the  diameter  of  the  cell.  This  inner  lamina  he  thought  partook 
more  of  the  characteristic  of  a  serous  than  of  a  mucous  membrane.  This 
arrangement  of  the  cellular  elements  of  the  inner  layer  is  suggestive  of 
contractile  power  and  expelling  force. 

If  elastic  fibres  could  be  positively  demonstrated  as  forming  a  part  of 
the  structure  of  the  sac,  this  would  be  the  most  rational  theory  yet  ad- 
vanced, as  it  would  be  based  upon  the  known  and  demonstrable  physiologic 
function  of  elastic  tissue.  In  support  of  this  supposition  it  has  been  stated 
that  inasmuch  as  in  the  periosteum  elastic  fibres  are  present  in  that  portion 
of  the  membrane  which  lies  nearest  to  the  bone,  being  in  the  form  of  a  fine 
fibrous  net-work,  that  they  must  also  be  present  in  the  structure  of  the 
pericementum,  which  is  very  similar  to  that  of  the  periosteum.  Black, 
however,  in  his  researches  upon  the  histology  of  the  pericemental  mem- 
brane, was  unable  to  positively  demonstrate  the  presence  of  elastic  fibres. 
He  found  the  membrane  to  be  composed  almost  entirely  of  white  fibrous 
tissue,  but  when  the  white  fibres  were  dissolved  by  the  usual  reagents — 
solutions  of  caustic  potash — no  elastic  fibres  could  be  discovered. 

Another  theory  presented  was  that  the  eruption  of  the  teeth' was  caused 
by  the  moulding  or  building  of  the  alveolus  around  the  roots.  This  theory 
is  easily  disposed  of  by  the  statement  that  the  alveolus  is  not  formed  around 
the  root,  nor  the  root  completed,  until  after  the  tooth  has  been  erupted. 
At  the  time  of  the  eruption  of  the  tooth  the  osteoclasts  have  made  an 
opening  in  the  cap  of  the  crypt  (Fig.  208)  large  enough  for  the  crown  to 
easily  pass  5  this  leaves  a  considerable  space  between  the  bone  and  the  root, 
which  is  occupied  by  the,  at  this  time,  thick  pericemental  membrane. 

The  latest  theory  is  that  suggested  by  Constant  (Journal  Britisli  Dental 
Association,  1896), — namely,  that  the  blood-xDressure  maybe  the  force  which 
impels  the  tooth  in  its  movement  from  the  cryj)t  and  through  the  gum, 
on  account  of  the  difference  in  the  blood-supply  of  the  parts. 

The  pulp  and  the  tissues  beneath  it  have  a  very  abundant  vascular 
supply,  while  those  above  are  not  so  richly  endowed,  C.  S.  Tomes,  in 
commenting  upon  this  theory,  says,  "  It  seems  very  possible  that  the 
blood- pressure  keeping  up  a  state  of  general  tension  may  operate  to  push 
a  solid  body  in  any  direction  in  which  there  is  a  diminished  resistance. 


62  OPERATIVE    DENTISTRY. 

to  take  up,  so  to  si^eak,  any  unoccupied  space  ;  but  it  is  difficult  to  see 
how  it  could  be  efficient  without  some  such  concomitant  action  of  absorp- 
tion. For  the  movement  of  an  erupting  tooth  is  not  alwaj^s  by  any  means 
in  the  direction  of  its  long  axis  ;  for  instance,  the  developing  tooth  of  the 
frog,  the  newt,  or  of  the  crocodile  takes  a  sidewise  journey,  by  which  it 
travels  underneath  the  old  tooth  before  it  moves  upward  at  all." 

But  if  its  path  be  prepared  by  absorption  of  the  structures  in  its  way, 
then  it  is  very  possible  that  the  blood- pressure  keeping  up  a  certain  gen- 
eral tension  may  suffice  to  move  it  along  a  track  of  diminishing  resistance. 
Mr,  Constant's  suggestion,  with  a  little  modification,  is  the  most  plausible 
that  has  been  offered,  therefore,  as  to  the  actual  motive  force  ;  whether  it 
will  be  regarded  as  a  final  solution  of  the  question  time  alone  can  show." 

What  are  the  forces  which  set  in  operation  the  process  of  eruption  ?  is  a  ques- 
tion which  very  naturally  arises  in  discussing  this  phase  of  the  phenomenon 
of  the  eruption  of  the  teeth.  If  the  lengthening  of  the  root,  the  elonga- 
tion of  the  pulp,  or  the  blood-pressure  within  the  pulp  are  not  sufficient 
as  mechanical  forces  to  produce  the  adequate  i)ressure  or  mechanical  irri- 
tation necessary  to  stimulate  the  osteoclasts  to  the  performance  of  their 
function  of  tearing  down  the  structures  which  their  sister  cells,  the  osteo- 
blasts, had  so  lately  built  up,  what  other  force  or  forces  are  operative  in 
establishing  this  phenomenon  %  It  is  possible  that  it  is  due  to  some  change 
in  the  nutrition  of  the  walls  of  the  crypt  and  the  gums,  induced,  perhaps, 
by  the  withdrawal  of  a  portion  of  its  blood-supply,  as  a  result  of  the 
greater  activity  in  the  growth  of  the  tooth-follicle  just  preceding  and 
during  the  period  covered  by  the  process  of  the  extrusion  of  the  crown. 
In  some  such  change  as  this  in  the  nutrition  of  the  part  the  resorption  of 
the  alveolus  is  induced  after  the  extraction  of  a  permanent  tooth. 

The  whole  subject,  it  will  be  seen,  is  far  from  being  satisfactorily  set- 
tled, either  as  to  the  conditions  which  induce  resorption  or  the  forces  which 
are  operative  in  extruding  the  tooth-crown  from  its  crypt  to  its  normal 
position  in  the  mouth. 

When  the  formation  of  the  tooth  has  arrived  at  that  stage  in  which  it  is 
ready  to  be  extruded,  and  this  occurs  in  the  deciduous  central  incisors, 
which  are  the  first  to  be  erupted,  at  the  fifth  to  the  eighth  month  after 
birth,  a  very  active  process  of  resorption,  the  result  of  a  low  inflammatory 
condition,  takes  place  in  the  walls  of  the  bony  crypt  in  which  the  crown 
of  the  tooth  is  lodged.  This  process  is  most  active  at  the  anterior  or  labial 
wall  and  the  roof  of  the  crypt,  by  which  the  upper  portion  of  the  sac  and 
the  bony  tissue  are  removed,  as  shown  in  Fig.  209,  while  the  posterior  or 
lingual  wall  remains  unchanged,  as  it  is  required  to  form  the  labial  wall 
of  the  crypt  of  the  successional  tooth.  Prior  to  this,  however,  there  is 
formed  in  the  tissues  immediately  above  the  bony  crypt  of  the  follicle  an 
inflammatory  area  in  which  resorption  vacuoles  are  formed  which  gradu- 
ally increase  in  size.  The  opening  made  by  this  process  (Fig.  210)  finally 
becomes  larger  than  the  diameter  of  the  crown,  thus  giving  it  a  roomy 
exit  I  but  as  soon  as  the  crown  has  passed  from  the  crypt  and  extruded 
through  the  gum,  the  process  of  resorption  gives  place  to  that  of  a  deposition 
of  new  osseous  material,  which  loosely  embraces  the  cervix  of  the  tooth. 


Alveolar 
bone 


Fig.  209. — Vertical  section  of  erupting  tooth  of  field-mouse,  showing  area  of  resorption,    x  75, 


Fig.  210.— Vertical  section  of  human  cuspid,     x  75. 


ERUPTIONT    OF    THE    TEETH. 


63 


Fig.  211. 


Rami  at  various  ages.     A,  childhood; 
B,  adult  life  ;  C,  old  age. 


Growth  of  the  Jaw. — As  the  root  of  the  tootli  increases  in  length 
additions  to  the  margin  of  the  alveolus  keep  pace  with  it ;  and  as  the 
process  is  a  somewhat  rapid  one,  the  increase  in  the  depth  of  the  jaw  is 
correspondingly  rapid.  This  phenomenon  begins  first  in  the  anterior 
portion  of  the  jaw  by  the  eruption  of  the 
incisor  teeth.  Later  the  first  molars  are 
extruded,  and  the  jaw  deepens  posteriorly  ; 
then  the  cuspids  make  their  appearance, 
and  still  later  the  second  molars,  producing 
a  corresponding  deepening  of  the  jaw  in 
these  locations.  During  this  time  there 
has  also  been  a  steady  lengthening  of  both 
the  horizontal  and  the  ascending  rami  of 
the  mandible,  with  a  considerable  change 
in  the  angle  formed  by  their  union.  These 
changes  progress  until  adult  life  is  reached, 
when  they  assume  an  angle  of  about  forty- 
five  degrees. 

In  old  age,  after  the  teeth  are  lost,  the 
alveolar  j)i*ocesses  are  resorbed,  and  the 
rami  again  assume  a  more  obtuse  angle, 
approaching  that  of  childhood.  (See  Fig, 
211.)  The  changes  which  occur  in  the -su- 
perior maxilla  are  similar,  so  far  as  the 
deepening  and  lengthening  of  the  jaw  are 

concerned,  to  those  which  take  place  in  the  growth  of  the  mandible, 
while  the  retrogressive  changes  are  confined  to  the  resorption  of  the 
alveolar  processes. 

The  eruption  of  the  teeth  is  not  a  continuous  process,  as  was  pointed 
out  by  Trousseau  ;  the  teeth  being  erupted  in  pairs  or  groups,  with  vary- 
ing periods  of  rest  between  them. 

The  deciduous  central  incisors  are  the  first  of  the  dental  seiies  to  be 
erupted  ;  the  ax)pearance  of  these  teeth  is  followed  by  a  period  of  rest  in 
the  process  of  from  one  to  two  months ;  the  lateral  incisors  are  next  ex- 
truded, and  their  appearance  is  followed  by  a  rest  of  from  five  to  six 
months.  The  first  molars  come  next,  and  these  are  followed  by  the  cus- 
pids, with  a  period  of  inactivity  in  the  process  between  them  of  from  two 
to  four  months.  The  second  molars  are  the  last  of  the  deciduous  teeth  to 
be  erupted,  and  they  make  their  appearance  from  six  to  twelve  months 
after  the  extrusion  of  the  cuspid.  It  will  therefore  be  seen  that  the  whole 
period  of  time  consumed  in  the  eruption  of  the  deciduous  teeth  is  about 
two  years,  but  the  actual  time  occupied  by  the  various  groups  of  teeth  in 
the  passage  from  their  bony  crypts  and  through  the  gum  to  their  normal 
positions  in  the  mouth  is  much  less  than  this;  the  usual  period  of  time 
consumed  by  each  group  is  only  from  four  to  eight  weeks. 

The  roots  of  the  deciduous  teeth  are  completed  in  formation  at  about 
the  following  periods  and  in  the  order  named,  but  no  positive  rule  can  be 
laid  down  from  which  frequent  deviations  will  not  be  observed  : 


64  ■  OPERATIVE    DENTISTRY. 

The  central  incisors  are  completed  at  about  the  age  of 2    years. 

The  lateral  incisors  are  completed  at  about  the  age  of 2i  years. 

The  first  molars  are  completed  at  about  the  age  of .2}  years. 

The  cuspids  are  completed  at  about  the  age  of 2'i  years. 

The  second  molars  are  completed  at  about  the  age  of 3    years. 

Fig.  212  shows  tlie  jaws  of  a  child  at  three  to  tliree  and  a  half  years  of 


age. 


MOEBID    PRIMARY   DENTITION. 


The  eruption  of  the  teeth  in  a  normal  child  is  productive  of  so  little 
general  or  local  disturbance  that  many  times  the  teeth  make  their  appear- 
ance within  the  mouth  before  the  parent  or  nurse  have  realized  the  fact 
that  the  process  of  '' teething"  had  really  begun  ;  while,  upon  the  other 
hand,   in  children  with  impaired  health  and  low  vitality  it  often  plays  a 

Fig.  212. 


Jaws  of  a  child  of  three  to  three  and  a  half  years  of  age. 


prominent  part  in  exciting  various  morbid  conditions  of  the  digestive, 
nervous,  respiratory,  and  dermal  systems.  The  subject  becomes,  therefore, 
one  of  considerable  interest,  alike  to  the  general  practitioner  and  to  the 
dental  specialist.  There  is  no  doubt  that  the  dangers  from  dentition  have 
been  greatly  exaggerated  by  some  authorities,  and  that  parents  are  often 
unnecessarily  anxious  for  their  offspring  during  this  period  ;  yet  it  must  be 
borne  in  mind  that  in  certain  temperaments  and  under  various  physical 
conditions  and  environment  there  is  a  real  degree  of  danger  present,  and 
that  morbid  phenomena  are  sometimes  excited  which  may  progress  to  a 
fatal  termination. 

According  to  the  mortality  tables  of  London,  as  cited  by  West,  denti- 
tion was  assigned  as  the  cause  of  death  of  4.8  per  cent,  of  all  children 


Deciduous  tooth 


Follicle  of 
permanent  tooth 


Fig.  218.-Vertical  section  of  jaw  of  embryo  cat,  showing  deciduous  tooth  and  follicle  of  permanent  tooth. 


X  90. 


Follicle 
of  per- 
manent 
tooth 


Fig.  2U.— Oblique  section  of  jaiv  of  embryo  cat,  showing  deciduous  tooth  and  follicle  of 


permanent  tooth.     X  fO. 


ERUPTION    OF    THE    TEETH.  65 

dying  under  one  year  of  age,  and  7.3  per  cent,  of  those  who  died  between 
the  ages  of  one  and  three  years. 

The  dangers  surrounding  the  period  of  dentition  are  much  greater  in 
large  cities  and  in  overcrowded  localities,  particularly  among  the  middle 
and  lower  classes  of  society,  than  in  the  suburban  and  county  districts. 
But  the  greatest  mortality  is  in  the  foundling  hospitals  and  in  overcrowded 
and  filthy  tenements. 

It  therefore  becomes  a  question  of  how  much  of  this  mortality  is  really 
due  to  the  nervous  irritation  induced  by  the  eruption  of  the  teeth,  or  to 
other  concomitant  causes.  Errors  in  diagnosis  of  abnormal  conditions  oc- 
curring at  this  period  are  by  no  means  uncommon,  and  it  is  to  be  feared  that 
dentition  is  sometimes  made  the  scapegoat  for  the  ignorance  of  a  medical  or 
dental  attendant,  or  the  carelessness  or  indiscretions  of  the  parents  or  nurse. 

Contemporaneously  with  the  eruption  of  the  teeth  there  is  a  very  im- 
portant developmental  process  taking  place  in  the  follicular  or  glandular 
apparatus  of  the  whole  alimentary  canal,  in  preparation  for  the  necessary 
change  soon  to  take  place  in  the  character  of  the  food. 

This  is  a  x>hysiologic  process,  and  under  normal  conditions,  when  all 
of  the  functions  of  the  body  are  nicely  balanced,  progresses  without  any 
disturbance  of  the  general  health  ;  but  under  opposite  conditions  it  may  be 
productive  of  serious  gastric  and  intestinal  complications,  the  causes  of 
which  are  often  entirely  overlooked,  and  the  disturbances  which  are  the 
result  of  this  process  are  attributed  to  morbid  dentition. 

The  nervous  system  of  the  child  at  this  period  is  also  very  imj)ressible, 
the  cerebro-spinal  apparatus  j)redominating  to  such  an  extent  that  slight 
irritations  of  almost  any  character,  in  children  of  certain  temperaments, 
may  be  followed  by  more  or  less  general  systemic  disturbance,  with  eleva- 
tion of  temperature,  vomiting,  diarrhoea,  bronchitis,  and  other  catarrhal 
conditions,  or  reflex  nervous  phenomena,  like  strabismus,  twitching  of  the 
facial  muscles,  rolling  of  the  eyes,  convulsions,  or  meningitis. 

Dental  Irritation. — The  nervous  irritation  accompanying  the  erup- 
tion of  the  deciduous  teeth  may  be  caused  by  one  or  all  of  the  following 
conditions : 

1.  By  the  very  active  evolutionary  process  going  on  within  the  jaws  at 
this  period. 

2.  By  the  lateral  pressure  induced  within  the  jaws  by  the  contempora- 
neous evolution  of  two  sets  of  teeth. 

3.  By  peripheral  irritation  of  the  gingival  nerves  from  the  pressure  of 
the  advancing  teeth. 

(1)  The  very  active  evolutionary  process  which  is  going  on  within  the 
jaws  at  the  period  of  the  eruption  of  the  teeth  calls  for  a  much  larger 
volume  of  blood  within  the  i^arts  than  is  normal  at  a  later  period  in  life. 
The  illustrations  shown  in  Figs.  213  and  214,  made  from  the  jaw  of  an 
embryo  cat,  show  what  a  considerable  amount  of  space  is  occupied  in  the 
jaws  at  this  period  of  dental  evolution  by  the  follicles  of  the  teeth.  This, 
under  certain  conditions  which  have  already  been  mentioned,  often  pro- 
duces over-stimulation  of  the  parts,  followed  by  congestion,  which  may 
induce  reflex  nervous  phenomena,  or  through  the  sym]3athetic  nervous 

5 


6Q  OPERATIVE    DENTISTRY. 

system  establish  morbid  conditions  of  the  stomach,  the  bowels,  the  respira- 
tory tract,  the  skin,  etc. 

(2)  The  lateral  pressure  induced  within  the  jaws  by  the  contempora- 
neous evolution  of  two  sets  of  teeth  must  be  very  considerable  at  this  pe- 
riod. If  the  jaws  of  a  child  six  months  old  are  examined  it  will  be  noticed 
that  the  permanent  teeth  in  various  stages  of  development  are  so  crowded 

together  that  their  crypts  overlap  each 
Fig.  215.  other,  but  each  apparently  is  striving  to 

obtain  a  normal  position.  As  the  growth 
and  enlargement  of  the  jaws  takes  place 
they  gradually  assume  their  proper  posi- 
tions within  the  arch,  ready  to  advance 
as  soon  as  the  way  is  made  clear  for  them 
by  the  lengthening  of  the  jaws  and  the 
exuviation  of  the  deciduous  teeth  (Fig. 
215). 

(3)  The  peripheral  irritation  of  the 
gingival  nerves  from  the  pressure  of  the 
advancing  teeth  is  often  under-estimated, 
as  any  individual  will  readily  admit  who 

tirst  and  second  dentition,  upper  and  lower   Jias     Suffered     from     the     eruption    of     a 

™*^^  ^'  troublesome  third  molar. 

In  viewing  the  subject  of  dental  irritation  from  this  stand-point  the 
wonder  would  seem  to  be  that  morbid  phenomena  are  not  more  often 
manifested  than  they  are  during  the  eruption  of  the  deciduous  teeth. 

Symptoms. — The  symptoms  of  dental  irritation  may  be  classified 
under  two  heads, — viz.,  constitutional  and  local. 

The  constitutional  symptoms  which  may  be  manifested  as  complications 
during  the  period  of  first  dentition  are  fever,  diarrhoea,  vomiting,  cough, 
bronchitis,  various  eruptions  of  the  skin,  occasionally  swelling  and  suppura- 
tion of  the  lymphatic  glands,  and  nervous  phenomena  like  spasms  of  the  facial 
muscles,  "which  send  doting  mothers  into  ecstasy  over  the  heavenly  smile 
of  the  sleeping  infant,"  strabismus,  chorea,  convulsions,  and  meningitis. 

Pyrexia,  or  fever ^  is  perhaps  the  most  common  constitutional  symjptom 
or  complication  of  morbid  primary  dentition.  The  character  of  the  fever 
may  be  mild  or  intense,  according  to  the  degree  of  suscei)tibility  of  the 
child  to  nervous  irritation,  and  there  is  a  marked  difference  in  children  in 
this  respect.  In  one  child  the  elevation  of  temperature  may  be  slight,  not 
going  above  100°  F.,  while  in  another,  with  apparently  no  greater  cause 
for  an  abnormal  rise  in  temperature,  it  may  reach  103°  or  104°  F. ,  and  be 
accompanied  with  gastric  or  intestinal  disturbances  or  convulsions. 

The  fever  of  dentition,  which  is  irritative  in  character,  is  peculiar  in 
that  it  is  very  irregular  in  its  manifestations.  It  is  often  higher  in  the 
morning  than  in  the  evening,  reversing  the  usual  order,  and  it  varies  con- 
siderably from  day  to  day.  A  high  morning  temperature  often  follows  a 
restless  night,  and  a  low  evening  temperiature  follows  a  quiet  day.  Great 
Adgilance  should  characterize  the  care  of  children  when  suffering  from  the 
irritative  fever  of  dentition.    A  feverish  child  is  very  susceptible  to  sudden 


ERUPTION    OF    THE    TEETH.  67 

clianges  of  the  weather  from  a  dry  to  a  damp  atmosphere,  from  a  warm  to 
a  cold  room,  or  to  cold  draughts,  and  to  improper  feeding.  Too  much 
emphasis  cannot  be  placed  upon  the  importance  of  iDroperly  protecting  the 
child  against  these  contingencies.  Catarrhal  attacks  at  this  period  are  far 
more  likely  to  be  the  result  of  exposure  which  has  induced  a  chill,  or  to 
improper  feeding,  than  to  mechanical  irritation  of  the  gingival  nerves  by 
an  erupting  tooth. 

Diarrhoea  is  another  very  common  complication  of  morbid  dentition, 
but  dental  irritation  is  by  no  means  the  most  common  cause  of  diarrhoea. 
Catarrhal  conditions  of  the  stomach  and  bowels  are  very  jDrevalent  at  this 
period  5  but  in  the  opinion  of  the  writer  these  conditions  are  more  often 
the  result  of  bad  sanitary  and  hygienic  surroundings,  exposure  to  cold,  or 
improper  feeding  and  unwholesome  food  than  to  any  other  cause  or  causes. 

Diarrhoea  and  vomiting  are  most  prevalent  during  the  hot  months  of 
the  year,  when  the  changes  in  the  weather  are  often  the  greatest  and  the 
clothing  of  the  child  least  likely  to  afford  the  pro]3er  protection  against  a 
sudden  fall  in  the  temxDerature.  The  food  also  is  more  liable  to  be  ren- 
dered unwholesome  by  fermentative  changes  during  the  hot  weather  than 
at  any  other  time.  A  chill  or  a  cup  of  milk  partially  changed  by  lactic 
acid  fermentation,  or  the  impure,  chemically  preserved  stuff  often  sold  in 
our  large  cities  as  pure  milk,  are  responsible  for  a  large  majority  of  the 
cases  of  gastric  and  intestinal  disturbances  and  nervous  phenomena. 

Parents  and  nurses  through  ignorance  or  carelessness  often  feed  little 
children  with  foods  that  their  stomachs,  at  this  early  age,  are  incapable  of 
digesting  5  for  instance,  meats,  hard-boiled  eggs,  beans,  cabbage,  bananas, 
apples,  cherries,  and  many  other  similar  things ;  and  then,  if  the  child's 
stomach  refuses  afterwards  to  retain  food,  or  it  suffers  from  diarrhoea  or 
cholera  infantum  or  convulsions,  and  as  a  result  gives  up  its  puny  life,  the 
illness  or  the  death  is  often  charged  to  teething. 

Bronchitis  is  usually  attributed  to  ordinary  exposure,  and  yet  it  some- 
times occurs  in  children  in  whom  every  precaution  has  been  taken  to  pre- 
vent chilling  the  surface  of  the  body  ;  under  such  circumstances  it  may  be 
the  result  of  dental  irritation. 

Cutaneous  eruptions  frequently  occur  during  primary  dentition,  such  as 
urticaria,  eczema,  impetigo,  lichen,  prurigo,  and  herpes  zoster,  which  are 
often  the  exj)ression  of  reflex  nervous  irritations. 

Reflex  nervous  phenomena^  associated  with  morbid  dentition,  are  of  the 
most  varied  character,  both  as  to  degree  and  the  peculiarities  of  their 
manifestations.  These  manifestations  are  often  difficult  to  understand, 
and  still  more  difficult  to  trace  to  their  origin.  Pepper  says,  in  explana- 
tion, "Doubtless  the  extensive  ramifications  of  the  great  vagus  nerve  and 
its  connections,  both  of  origin  and  distribution,  with  the  exquisitely  sen- 
sitive fifth  nerve,  as  well  as  with  the  facial  nerve,  and  with  the  sympa- 
thetic system,  will  explain  why  the  irritation  should  now  be  seated  in  the 
gastro- intestinal  tract,  giving  rise  to  vomiting  and  diarrhoea  5  now  in  the 
respiratory  tract,  provoking  cough  more  or  less  severe,  or  even  a  well- 
marked  bronchitis ;  now  manifests  itself  in  various  cutaneous  eruptions ; 
now  accumulates  in  the  cerebro-spinal  axis,  manifesting  its  presence  by 


68  OPEKA.TIVE   DENTISTRY. 

slight  spasms,  or  dischargiug  with  terrific  force  in  some  of  those  convul- 
sive seizures  which  are  the  dread  of  mothers  and  the  cause  of  much  anxiety 
to  physicians." 

The  second  summer  is  generally  considered  as  the  most  critical  period  in 
the  life  of  the  infant,  the  popular  notion  being  that  the  dangers  and  com- 
plications which  arise  are  largely  due  to  the  eruption  of  the  cuspid  and 
molar  teeth,  as  one  or  the  other  of  these  groups  usually  makes  its  appear- 
ance at  about  this  time.  There  is  really  no  reason  why  a  cuspid  or  molar 
tooth  should  cause  a  greater  degree  of  irritation  than  an  incisor  ;  while, 
upon  the  other  hand,  in  a  normal  child,  with  the  increase  in  the  age  and 
strength,  there  usually  comes  greater  resistive  power  to  such  forms  of  irri- 
tation ;  consequently  the  second  summer  should  be  less  dangerous  than  the 
first  so  far  as  dentition  is  concerned. 

The  dangers  associated  with  the  second  summer  do  not  in  any  great 
measure  depend  upon  dental  irritation,  but  rather  upon  improper  feeding. 
Children  of  this  age  are  prone  to  devour  anything  that  may  be  given  to 
them,  or  upon  which  they  can  lay  their  hands,  and  unless  they  are  care- 
fully watched  and  strict  supervision  instituted  over  their  food,  as  to  its 
kind,  quality,  and  quantity,  many  illnesses  are  likely  to  occur  ;  and  if  a 
group  of  teeth — the  cuspids  or  molars — should  be  erupting  when  the 
illness  supervened,  the  chances  are  that  they  would  be  considered  the 
primary  cause  of  the  derangement  rather  than  the  ingestion  of  indiges- 
tible substances  or  foods  in  which  fermentative  processes  had  already  been 
established.  When  these  conditions  are  complicated  with  the  debility  con- 
sequent upon  previous  disease  or  a  period  of  intense  heat,  the  results  often 
prove  fatal. 

A  very  large  percentage  of  all  the  children  born  die  before  they  reach 
the  end  of  the  fifth  year  as  a  result  of  the  diseases  and  accidents  peculiar 
to  this  period  of  life.  Arbuthnot  calculates  that  one  in  every  ten  children 
dies  from  the  effects  of  the  associative  and  influenced  lesions  of  the  age. 
(Garretson.)  The  mortality  among  hand-fed  children  is  much  greater  than 
this.  Camper  is  the  authority  for  the  statement  that  out  of  five  thousand 
nine  hundred  and  eighty-nine  children  admitted  to  foundling  hospitals, 
only  eight  hundred  and  eighty-four  were  found  living  at  the  end  of  the 
fifth  year  (Garretson),  or  85. 239  per  cent,  had  died. 

Eouth  says,  in  this  connection,  ' '  In  England,  out  of  one  hundred  chil- 
dren born  and  fed  by  hand,  15.2  per  cent,  will  die  the  first  month,  1.7  the 
second,  and  so  on.  In  France,  out  of  one  million  births,  20,121  die  in  the 
first  week,  22,128  in  the  second,  and  22,236  in  the  sixteen  days  following." 

According  to  the  English  Life  Table,  ' '  the  annual  rate  of  mortality 
among  infants  per  thousand  is  equal  to  571.3  in  the  first  mouth  of  life,  de- 
clining, however,  to  91.6  per  thousand  in  the  eleventh  month.  The 
annual  rate  among  infants  aged  one  month  and  under  one  year  does  not 
exceed  114.6  per  thousand,  whereas  among  infants  from  birth  to  one  year 
of  age  it  is  equal  to  165.6  per  thousand. 

''Among  infants  of  six  months  the  mortality  is  but  one-fifth  of  the 
rate  which  i)re vails  during  the  first  month  of  life."  {British  Medical  Jour- 
nal, vol.  i.,  1875,  p.  785.) 


ERUPTION   OF   THE   TEETH. 


69 


The  report  of  the  Eegister-General  of  England  for  1897  shows  that  "under 
the  most  favorable  circumstances  the  mortality  of  infants  under  one  year 
of  age  is  very  high.  Reference  to  several  life  tables  shows  that  the  same 
rate  of  death  is  not  again  experienced  until  the  age  of  about  eighty  years. 
But  the  mortality  in  the  first  year  of  life  is  by  no  means  evenly  spread 
over  that  year  ;  about  one-half  of  it  occurs  in  the  first  three  months.  The 
following  table  shows  the  survivors  at  three  months,  six  months,  and 
twelve  months  out  of  one  hundred  thousand  of  each  sex  born  in  1881-90  ; 
the  deaths  in  the  intervals  are  likewise  shown." 


England  and  Wales. 

England  and  Wales. 

Born  and  Surviving  at  Each  Age. 

Dying  in  Each  Interval  of  Age. 

Males. 

Born 100,000 

Three  months 93,791 

Six  months 88,895 

Males. 

Between  birth  and  three  months 7880 

Between  three  and  six  months 3225 

Between  six  and  twelve  months 4999 

Twelve  months 83,896 

Females. 
Born 100,000 

Females. 
Between  birth  and  three  months. .  . .  6209 

Three  months 93,791 

Between  three  and  six  months     ....  2653 

Six  months 91,138 

Twelve  months 86,887 

Between  six  and  twelve  months 4251 

The  rate  of  mortality  among  infants  of  both  sexes  under  the  age  of  twelve 
months  was  equal  to  142  i^er  thousand  births  registered  as  comj^ared  with 
149  per  thousand  in  the  preceding  decennium.  In  1881-90  the  infantile 
rate  among  males  was  equal  to  155  per  thousand  births,  and  among  females 
to  128  per  thousand,  the  rates  in  1871-80  having  been  163  and  134  re- 
spectively. 

Local  Symptoms. — The  local  symptoms  which  usually  accompany 
first  dentition  are  as  follows :  Salivation  is  the  first  indication  of  ap- 
proaching dentition.  From  birth  to  the  fourth  or  fifth  month  the  sali- 
vary glands  seem  to  remain  nearly  or  quite  inactive,  but  as  the  time  ap- 
proaches for  the  teeth  to  begin  the  process  of  eruption  the  salivary  glands 
take  on  a  marked  activity,  the  fiow  of  the  secretion  being  so  abundant  as  to 
cause  it  to  dribble  from  the  corners  of  the  mouth  and  to  wet  the  garments 
about  the  neck  and  chest.  This  wetting  of  the  clothing  is  often  respon- 
sible for  the  catarrhal  attacks  associated  with  dentition,  while  the  swal- 
lowing of  large  quantities  of  saliva  has  been  thought  in  some  cases  to  be 
responsible  (Pepper)  for  the  diarrhoea  by  reason  of  its  saline  constituents, 
which  may  act  as  a  mild  cathartic. 

Swelling  or  tumefaction  of  the  gums  is  next  observed,  at  about  the 
sixth  to  the  seventh  month,  in  those  locations  where  the  teeth  are  about  to 
be  erupted.  Sometimes  the  gums  become  congested,  tense,  glistening,  hot, 
and  painful ;  at  times  tender  to  the  touch,  but  generally  the  painful  sensa- 
tions are  relieved  by  pressure,  hence  the  desire  of  the  child  to  bite  upon 
hard  substances. 


70  OPERATIVE    DENTISTRY. 

Accompanying  these  local  symptoms  there  is  often  a  slight  elevation 
of  temperature  with  flushing  of  one  or  both  cheeks,  irritability  of  temper, 
peevishness,  and  restlessness  during  sleep,  with  rolling  of  the  head  from 
side  to  side.  Occasionally  the  child  sleeps  with  the  eyelids  only  half 
closed  or  the  eyes  rolled  upward.  Otalgia  is  not  an  uncommon  occur- 
rence, as  may  be  inferred  from  the  child  poking  its  fingers  into  the  ex- 
ternal meatus  or  pressing  its  ear  into  the  pillow  or  against  the  bosom  of 
the  nurse.  In  the  ordinary  cases  of  dentition  these  may  be  the  only  mani- 
festations. In  the  more  severe  cases  one  or  more  of  the  constitutional 
symptoms  above  described  may  be  present  as  comj)lications. 

Occasionally  there  exists  a  disposition  to  the  formation  of  aphthous 
patches,  ulcerous  stomatitis,  within  the  mouth,  upon  the  lips,  cheeks,  gums, 
and  tongue,  most  frequently,  however,  at  the  commissure  of  the  lips,  upon 
the  buccal  surface  of  the  alveolar  ridge,  and  the  tip  of  the  tongue ;  the 
latter  being  due,  in  all  probability,  to  the  friction  of  the  sharp  and  ser- 
rated edges  of  the  incisor  teeth. 

Sometimes  in  children  suffering  from  debility  the  aphthous  patches  be- 
come confluent,  forming  large  ulcerated  surfaces ;  or  the  gums  over  the 
advancing  teeth  become  ulcerated,  exceedingly  tender  and  painful, — odon- 
titis infantum, — or  gangrenous,  forming  large,  foul-smelling  sloughs, — gan- 
grena  oris, — which  expose  the  teeth  and  the  bone.  Both  of  these  conditions 
are  difficult  to  cure,  the  latter  often  taking  on  the  more  severe  and  fatal 
form  of  gangrenous  ulceration  known  as  noma. 

A  more  common  but  less  severe  form  of  stomatitis,  in  which  there  is  a 
general  inflammatory  condition  affecting  the  mucous  membrane,  and  espe- 
cially the  mucous  follicles  of  the  tongue  and  cheeks, — catarrhal  stomatitis, — 
accompanied  by  swelling  of  the  submaxillary  glands  and  infiltration  of  the 
surrounding  connective  tissue,  is  frequently  seen  in  the  children  of  the  very 
poor,  and  is  usually  associated  with  bad  or  insufficient  food  and  unsanitary 
surroundings. 

Constitutional  Treatment. — The  treatment  of  morbid  dentition  with 
its  constitutional  and  local  complications  generally  falls  to  the  lot  of  the 
family  physician,  and  the  dental  surgeon  or  stomatologist  is  rarely  con- 
sulted except  in  the  more  severe  cases  involving  serious  oral  lesions  or  re- 
flex phenomena  dependent  upon  oral  conditions.  It  will  not  be  necessary, 
therefore,  to  dwell  at  length  upon  the  treatment  of  the  various  general 
morbid  conditions  which  accompany  difficult  dentition,  as  these  belong  to 
the  realm  of  general  medicine,  and  those  especially  interested  in  this  part 
of  the  subject  can  refer  to  works  devoted  to  this  department  of  medical 
science.  It  will  be  sufficient  to  say,  then,  that  the  constitutional  symp- 
toms are  to  be  treated  upon  general  principles,  i\xQ  first  of  which  is  to  ascer- 
tain the  cause,  second,  to  remove  it  if  possible,  and  third,  to  assist  nature  in 
re-establishing  a  normal  condition.  It  will  not  be  amiss,  however,  to  quote 
a  few  lines  irom  Day  ("  Diseases  of  Children")  upon  this  part  of  the  subject. 
He  says,  "  The  treatment  of  dentition  will  depend  upon  the  general  symp- 
toms that  are  present  and  the  constitution  of  the  patient.  The  practi- 
tioner must  exercise  his  own  judgment  as  to  the  treatment  to  be  adopted, 
and  not  blindly  attach  himself  to  any  routine  plan.     The  strong  and  vig- 


ERUPTION    OF    THE    TEETH.  71 

orous  child  who  is  feverish  and  thirsty,  with  a  hot  and  tender  gum,  a  full 
pulse,  and  constipated  bowels,  will  demand  quite  a  different  mode  of  man- 
agement from  a  puny  and  rickety  child  whose  teeth  are  delayed.  In 
strong  children  a  grain  of  calomel  with  two  or  three  grains  of  rhubarb 
will  be  required  to  clear  the  bowels.  A  saline  mixture,  as  the  citrate  of 
potash,  should  be  given  to  abate  the  pyrexia,  and  if  the  child  is  excited 
and  sleepless,  a  few  drops  of  tincture  of  henbane  may  be  added,  or  a 
draught  at  bedtime  containing  hydrate  of  chloral  and  bromide  of  potas- 
sium should  be  given.  The  child's  head  should  be  kept  cool,  and  what- 
ever determines  to  cerebral  congestion  should,  if  possible,  be  prevented. 

''In  rickety  children  a  mild  aperient  is  occasionally  required,  such  as 
bicarbonate  of  soda  and  rhubarb,  to  regulate  the  bowels  and  to  correct  the 
secretions.  A  teasi^oonful  of  castor  oil  may  be  advisable  now  and  then, 
and  if  the  bowels  are  overactive,  a  grain  of  Dover's  powder  at  bedtime  is 
often  of  great  service.  If  there  is  vomiting  and  flatulence,  some  carmina- 
tive will  be  necessary.  In  cases  where  there  is  much  restlessness  and  dis- 
turbance of  the  nervous  system,  bromide  and  iodide  of  potassium  with  sal 
volatile  will  often  abate  sickness  and  relieve  head-symptoms  if  present." 

Local  Treatment. — In  those  cases  in  which  the  gums  are  considerably 
congested  and  swollen,  causing  jyain  on  pressure,  and  accompanied  with  gen- 
eral febrile  symptoms,  vomiting,  diarrhoea,  or  cough,  almost  immediate 
relief  is  often  obtained  by  the  free  use  of  the  gum-lancet.  To  be  effective 
the  lancet  must  reach  the  tooth.  The  incision  for  the  six  anterior  teeth  of 
each  jaw  should  follow  the  line  of  the  niorsal  or  the  cutting  edge  of  each 
tooth,  except  in  the  cuspids  when  the  cusp  has  penetrated  the  gum  (Fig. 
216),  when  the  incision  may  be  made  as  shown  in  Fig.  217,  while  for  the 

Fig.  216.  Fig.  217.  Fig.  218.  Fig.  219.  Fig.  220. 


molars  crucial  incisions  should  be  made,  one  from  the  disto-lingual  cusp 
to  the  mesio-buccal,  the  other  from  the  disto-buccal  cusp  to  the  mesio- 
lingual  (Fig.  218.) 

These  incisions  follow  the  line  of  the  cutting  edge  in  the  six  anterior 
teeth,  and  cut  directly  across  the  cusps  of  the  molar  teeth  which  are  nearest 
the  surface  of  the  gum  (Fig.  219),  and  for  that  reason  are  to  be  preferred 
to  those  which  are  made  upon  the  lines  of  the  sulci  between  the  cusps,  as 
shown  in  Fig.  220. 

The  indiscriminate  use  of  the  gum-lancet,  however,  should  be  depre- 
cated. Much  harm  has  often  been  done  by  a  thoughtless  or  empirical  use 
of  this  valuable  means  of  treatment,  while,  upon  the  other  hand,  many 
lives  have  been  saved  by  an  intelligent  use  of  it. 

Many  writers  and  physicians  of  experience  have  claimed  that  its  use  is 
never  indicated,  and  when  used  it  is  productive  of  more  harm  than  good. 


72 


OPERATIVE    DENTISTRY. 


The  same  has  been  said  of  blood-letting  in  pneumonia,  and  yet,  in  certain 
cases,  there  is  not  a  more  valuable  means  of  treatment  known  to  medicine 
than  this  once  much-abused  and  now  often- maligned  procedure.  The  dif- 
ficulty and  danger  in  both  of  these  methods  of  treatment  do  not  lie  in  the 
methods,  but  in  the  discriminating  power  of  the  person  who  employs  them. 
If  the  gum-lancet  is  applied  before  the  tooth  has  advanced  from  its 
crypt,  the  incision  will  necessarily  be  deep,  and  the  end  sought  for— viz., 
the  extrusion  of  the  tooth  through  the  gum— will  not  be  realized ;  conse- 
quently the  lips  of  the  incision  will  unite  again  ;  and  if  this  procedure  is 
repeated,  and  it  frequently  is,  a  mass  of  cicatricial  tissue  is  formed  that  is 
likely  in  a  frail  and  debilitated  child  to  become  the  seat  of  ulceration 
when  the  tooth  shall  finally  make  its  appearance  through  the  gum.  Such 
an  indiscreet  use  of  the  gum-lancet  cannot  be  too  strongly  condemned,  for 
the  irritation  certainly  does  not  come  from  pressure  upon  the  gingival 
nerves  until  the  tooth  advances  from  its  crypt. 

Dental  irritation  which  does  not  produce  local  symptoms  within  the 
mouth — swelling  or  congestion  of  the  gum,  or  both — is  not  due  to  pressure 
upon  the  gingival  nerves,  but  rather  to  one  or  both  of  the  other  causes  of 
dental  irritation  before  mentioned. 

The  ojyeration  of  lancing  the  gums  is  best  performed  with  the  assistance  of 
a  nurse.  In  operating  upon  the  lower  jaw  the  child  should  be  seated  in 
the  lap  of  the  operator,  with  its  head  against  his  breast,  the 
Fig.  221.  j^ands  and  feet  being  controlled  by  the  nurse.  The  left  thumb 
of  the  operator  is  placed  in  the  mouth  of  the  child  upon  the 
tongue,  the  index-finger  between  the  alveolar  ridge  and  the 
lower  lip,  with  the  remaining  fingers  under  the  chin.  In  this 
way  the  head  can  be  firmly  held,  the  tongue  controlled,  and  the 
lip  held  out  of  the  way  ;  it  also  gives  a  good  view  of  the  inferior 
alveolar  arch,  and  permits  the  operator  to  reach  any  i^art  of  it 
with  the  lancet.  The  best  form  of  gum-lancet  is  shown  in  Fig. 
221,  which  is  a  flat  blade  turned  at  right  angles  to.  the  shaft, 
and  having  a  sharp,  rounded  edge. 

In  oxDerating  upon  the  uj)per  jaw  the  child  should  be  laid 
upon  its  back  in  the  lap  of  the  nurse,  with  its  legs  passing  under 
her  arms,  while  the  arms  of  the  child  are  held  firmly  to  its 
sides.  The  head  should  be  held  between  the  knees  of  the  oi^er- 
ator.  One  or  more  fingers  of  the  left  hand  of  the  oiDerator  are 
then  inserted  within  the  mouth  of  the  child,  and  the  alveolar 
ridge  grasped  with  the  thumb  and  index-finger.  The  gum- 
lancet  should  be  held  in  the  right  hand  as  a  pen  or  pencil  is  held,  and 
the  hand  should  be  steadied  by  resting  the  ring-finger  and  the  little  finger 
upon  some  convenient  portion  of  the  face  while  the  incisions  are  being 
made. 

Sometimes  it  becomes  necessary  in  the  eruption  of  the  molar  teeth  to 
remove  the  band  of  overlying  gum-tissue  which  remains  after  the  cusps 
have  pierced  the  gum,  as  it  seems  to  retard  the  extrusion  of  the  tooth. 
This  can  be  best  accomplished  by  a  pair  of  sharp-pointed  curved  scissors 
(Fig.  222). 


Gum-lancet. 


EEUPTIOX    OF    THE    TEETH. 


73 


Troublesome  liemorrliage  occasionally  follows  lanciug  of  the  gums,  but, 
as  a  rule,  the  bleeding  is  so  slight  as  not  to  need  any  especial  attention. 

In  troublesome  hemorrhage  the  bleeding  gums  may  be  bathed  with  a 
strong  solution  of  alum,  or  touched  with  an  alum  pencil,  or  tannic  acid 
in  glycerol  may  be  applied  upon  a  piece  of  gauze  or  absorbent  cotton.  In 
obstinate  cases  a  compress  a]3X)lied  to  the  bleeding  part,  and  the  jaws  closed 
upon  it  and  held  in  that  position  by  a  bandage  passed  under  the  chin  and 
over  the  head,  will  usually  control  it. 

The  application  of  Monsel's  solution  or  the  nitrate  of  silver  is  recom- 
mended by  several  authorities,  but  this  is  rather  dangerous  practice,  from 

Fig.  222. 


the  fact  that  they  cause  sloughing  of  the  surface  of  the  gum-tissue  ;  this  is 
often  followed  by  secondary  hemorrhage,  which  is  sometimes  more  trouble- 
some to  control  than  the  primary  bleeding. 

As  a  constitutional  remedy,  tincture  of  ergot  in  one-  to  five- drop  doses 
in  a  little  water,  repeated  every  ten  minutes  until  bleeding  ceases,  or  until 
twenty  to  thirty  drops  have  been  administered,  will  usually  prove  effective. 


EXUVIATION   OE   SHEDDING   OF   THE   DECIDUOUS   TEETH. 

Definition. — The  exuviation  of  the  deciduous  teeth  is  a  peculiar 
physiologic  process,  whereby  the  roots  of  the  teeth  are  gradually  dis- 
solved— organic  and  inorganic  material — and  their  elements  removed  by 
resorption. 

It  may  truthfully  be  said  that  the  process  of  the  evolution  of  the 
temporary  teeth  is  hardly  completed  before  preparations  are  made  for  a 
retrograde  change  which  shall  result  in  the  tearing  down  of  these  struc- 
tures, which  have  been  so  carefully  and  elaborately  built,  to  make  room 
for  those  larger  and  more  permanent  organs  which  are  intended  to  serve 
the  body  to  the  end  of  life. 

The  process  of  exuviation  begins  in  the  central  incisors  in  about  a  year, 
or  a  little  more,  after  the  complete  formation  of  their  roots, — viz.,  in' the 
middle  or  latter  part  of  the  third  year, — but  it  is  not  completed  until  about 
the  seventh  year,  when  their  crowns  fall  out  from  lack  of  support.  The 
lateral  incisors  are  attacked  a  few  months  later  than  the  centrals,  and  are 
shed  at  seven  and  one-half  to  eight  years  of  age.  The  process  begins  in 
the  first  molars  at  the  age  of  six  and  one-half  to  seven  years,  terminating 


76  OPEEATIVE    DENTISTRY. 

tissue,  instances  of  which  are  common  in  the  practice  of  orthodontia. 
In  moving  a  tooth  from  an  abnormal  to  a  normal  position  the  orthodontist 
depends  upon  his  power  to  produce  resorption  of  the  alveolar  process  by- 
applying  mechanical  pressure  in  a  certain  direction. 

Resorption  of  bone  is  often  brought  about  by  the  pressure  of  an  en- 
larging aneurism  or  of  the  accumulations  of  fluid  or  of  pus,  as,  for  in- 
stance, in  the  maxillary  sinus,  where  it  sometimes  results  in  the  rupture 
of  one  of  the  walls  of  the  sinus. 

The  active  agent,  apparently,  which  produces  the  resorption  of  the 
roots  of  the  deciduous  teeth  is  a  soft,  highly  vascular  papilla, — the  "  ab- 
sorbent organ," — which  is  found  in  close  contact  with  the  root  of  the  tooth. 

The  surface  of  the  papilla  is  composed  of  very  large  multiform  cells, — 
giant  cells, — each  cell  being  composed  of  several  smaller  ones,  the  number 
varying  from  two  or  three  to  twelve  or  fifteen.  The  prevailing  forms  of 
the  cells  are  ovoid  and  spherical,  although  some  of  them  have  the  appear- 
ance of  the  myeloid  cells  of  Kolliker  (Fig.  224).  The  excavated  surface  of 
the  tooth  lying  next  to  the  absorbent  organ,  if  examined  microscopically, 
is  seen  to  be  covered  with  numerous  very  small  cup-shaped  indentations, — 
the  lacunae  of  Howship, — in  which  a  giant  cell  has  evidently  been  lodged. 

The  modus  oj>erandi  by  which  these  giant  cells  affect  a  dissolution  of  the 
dental  tissues  is  not  definitely  known.  Giant  cells,  however,  are  always 
present  wherever  the  resorption  of  hard  tissues  like  bone  is  going  on,  or 
foreign  substances  located  in  the  body  that  are  capable  of  being  dissolved. 
The  giant  cells  which  compose  the  "absorbent  organ"  are  no  doubt  modi- 
fied osteoclasts  derived  from  the  pericemental  membrane  of  the  decidu- 
ous teeth,  and  perform  the  same  office  for  the  teeth  that  the  osteoclasts  do 
for  the  bone,  and  are  known  as  "odontoclasts." 

Several  theories  have  been  advanced  in  explanation  of  the  process  of 
resorption  of  the  deciduous  teeth. 

It  was  thought,  until  quite  a  recent  period,  to  be  due  to  the  formation  or 
secretion  of  an  acid  by  the  "absorbent  organ,"  which  attacked  the  dental 
tissues  and  dissolved  them,  and  that  these  elements  were  then  removed  by 
the  absorbents  and  carried  into  the  general  circulation. 

Abbott  advanced  the  theory  that  the  absorbent  organ  was  not  the  active 
agent  in  the  resorption  of  the  temporary  teeth,  but  rather  the  result  of  it. 
The  process  of  resorption,  he  believed,  was  brought  about  through  the 
living  matter,  the  organic  basis  substance  of  the  dental  tissues,  by  a  retro- 
grade metamorphosis,  or  a  change  to  embryonal  tissue,  and  that  the 
process  is  closely  allied  to  that  of  inflammation.  That  the  lime-salts  are 
first  dissolved  and  the  basis  substance  or  organic  material  is  afterwards 
liquefied.  Medullary  elements  then  arise  out  of  the  liquefied  material  and 
proliferate,  resulting  in  a  new  formation  of  medullary  tissue,  the  so-called 
"  absorbent  organ." 

Black  has  suggested  the  most  rational  explanation  of  the  process,  one 
which  is  in  entire  harmony  with  the  latest  developments  in  physiology, — 
namely,  that  the  absorbent  organ  secretes  or  elaborates  a  digestive  fluid 
or  soluble  ferment  which  dissolves  or  digests  the  dental  tissues  and  alveolar 
walls,  and  prepares  them  to  be  resorbed,  just  as  under  certain  circumstances 


Pig.  223.— Vertical  section  of  a  jirculiar  ca^o  if  uxuviatiiai .  1"  a  tooth  in  the  jaw  of  a  kitten.     X  35. 


Fig.  224.— Absorbent  organ  and  portion  of  dentin  in  situ.     A,  giant  celis.     (V.  A.  Latham.)     X  G5. 


ERUPTION    OF    THE    TEETH.  77 

bone  is  resorbed,  or  ivory  pegs  wbicli  have  been  driven  into  tlie  tissues,  or 
catgut  sutures,  silk  ligatures,  decalcified  chicken-bone,  drainage-tubes,  or 
even  sponges  are  dissolved  and  removed  by  the  process  of  resorption. 

Devitalized  temporary  teeth  are  not  resorbed  ;  hence  it  would  seem 
that  the  vital  pulp  must  play  an  important  part  in  the  resorptive  process. 
Pierce  says  the  very  moment  vitality  of  the  pulp  ceases  that  instant  this 
retrograde  metamorphosis,  designated  "physiologic  absorption,"  termi- 
nates. 

Yital  permanent  teeth  sometimes  undergo  a  process  of  resorption  at 
various  points  upon  the  surface  of  their  roots  as  a  result  of  pericemental 
irritation  or  inflammation,  and  after  the  subsidence  of  the  morbid  condi- 
tion new  bone  or  cement  formation  takes  place  at  those  points  by  the  cal- 
cification of  the  absorbent  cells. 

Tomes  says,  ' '  The  process  of  absorption  once  commenced  does  not 
necessarily  proceed  without  intermission,  but  may  give  place  for  a  time  to 
actual  deposition  of  osseous  tissue  on  the  very  eroded  surface  ;  probably 
by  the  agency  of  the  absorbent  cells  themselves,  which  are  capable  of 
being  calcified  in  the  excavations  they  have  individually  made." 

Eeplanted,  transplanted,  and  implanted  teeth  are  often  attacked  by  a 
process  of  resorption  which  in  many  respects  is  quite  similar  to  the  re- 
sorptive process  which  removes  the  roots  of  the  deciduous  teeth.  This 
difference,  however,  is  to  be  noted,  that  while  in  the  deciduous  teeth  and 
vital  permanent  teeth  the  process  leaves  a  comparatively  smooth  exca- 
vation, in  devitalized  teeth  the  cementum  and  dentin  become  more  or 
less  roughened  and  honeycombed.  The  latter  process  is  also  attended  with 
considerable  soreness,  due  to  the  pericemental  inflammation,  and  pus  not 
infrequently  forms,  which  may  escape  around  the  cervix  of  the  tooth  or 
point  through  the  gum,  while  in  the  process  as  seen  in  the  exuviation  of 
the  deciduous  teeth  no  inflammatory  symptoms  are  present. 

The  former  is  a  patTiologic  process  established  to  remove  an  organ  which 
has  become  a  source  of  irritation  and  acts  as  a  foreign  body.  The  latter 
is  n  physiologic  process  established  to  remove  an  organ  which  has  served 
the  purpose  of  its  creation,  but  which  is  to  gradually  give  place  to  a 
stronger  and  more  enduring  counterpart  of  itself.  Pathology,  we  are 
taught  to  believe,  is  perverted  physiology  ;  but  just  where  normal  func- 
tion ceases  and  morbid  conditions  begin  science  has  not  as  yet  been  able 
to  demonstrate.  The  accompanying  diagram  (Fig.  225,  page  78),  drawn 
by  Professor  C.  E".  Peirce,  most  admirably  illustrates  the  periods  at  which 
calcification  takes  place  in  the  deciduous  and  the  permanent  teeth,  and 
also  the  decalcification  or  resorption  of  the  roots  of  the  deciduous  teeth. 

ERUPTION  OF  THE  PERMANENT  TEETH. 

Normal  secondary  or  permanent  dentition  begins  at  about  the  sixth  year 
by  the  eruption  of  the  first  molars,  which  take  position  directly  behind 
the  second  deciduous  molars,  the  growth  of  the  jaws  having  made  this 
possible  by  increasing  the  distance  between  the  second  deciduous  molar 
and  the  ascending  ramus  in  the  lower  jaw,  and  between  the  same  tooth  and 
the  tuberosity  in  the  upper  jaw. 


78 


OPERATIVE    DENTISTRY. 


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ERUPTION    OF    THE    TEETH.  79 

The  growttL  of  the  jaws,  which  keeps  pace  with  the  eruption  of  the  per- 
manent teeth,  is  mainly  confined  to  an  elongation  of  the  horizontal  ramus 
between  the  second  deciduous  molar  and  the  angle.  There  is,  however,  a 
certain  amount  of  growth  taking  place  at  the  symphysis  menti  and  at  the 
median  and  intermaxillary  sutures,  and  also  in  the  interstitial  substance 
of  the  jaws. 

This  statement  is  corroborated  by  the  fact  that  as  the  period  of  second 
dentition  approaches,  spaces  appear  between  the  deciduous  teeth  which 
gradually  widen  until  the  primary  teeth  are  exuviated.  The  widest  space 
in  the  lower  jaw  is  between  the  central  incisors,  while  in  the  upper  jaw  it 
is  between  the  central  incisors  and  between  the  lateral  incisors  and  cus- 
pids. ISTature  thus  beautifully  provides  for  the  increase  in  the  number 
and  of  the  size  of  the  succeeding  teeth  by  arranging  the  growth  of  the 
jaws  in  harmony  with  the  space  required  for  a  normal  arrangement  of  the 
individual  permanent  dental  organs. 

There  is  often  a  considerable  variation  in  the  time  and  order  of  the 
eruption  of  the  permanent  teeth,  even  in  healthy  individuals,  but  the  fol- 
lowing table  gives  approximately  the  date  and  the  order  in  which  they 
may  be  expected  to  appear  in  the  dental  arch  : 

First  molars 5    to    7  years  of  age. 

Central  incisors 6}  to    8  years  of  age. 

Lateral  incisors 7    to    9  years  of  age. 

First  bicuspids 9    to  11  years  of  age. 

Second  bicuspids 10    to  12  years  of  age. 

Cuspids 11    to  14  years  of  age. 

Second  molars lls^  to  13  years  of  age. 

Third  molars 16    to  21  years  of  age, 

or  at  any  period  later. 

The  third  molars  not  infrequently  fail  to  appear  at  all.  They  are  usu- 
ally developed,  but  remain  in  the  jaws  for  lack  of  space  in  the  arch  to 
accommodate  them,  or  are  so  malposed  that  their  eruption  is  dif&cult  or 
impossible. 

Symptoms. — The  symptoms  which  accompany  second  dentition  are 
usually  so  mild  as  not  to  attract  special  attention.  There  is  slight  saliva- 
tion and  a  little  tenderness  of  the  gums  over  the  erupting  teeth.  Occasion- 
ally, however,  marked  symptoms  may  be  present,  profuse  salivation,  great 
tenderness  and  tumefaction  of  the  gums,  sometimes  accompanied  with  ul- 
cerative stomatitis,  neuralgia  of  the  trifacial  nerves,  and  epileptic  seizures. 

The  eruption  of  the  third  molars,  particularly  the  inferior  ones,  is  often 
productive  of  great  suffering  from  inflammation  of  the  gums  and  surround- 
ing tissues.  Suppuration  not  infrequently  supervenes,  which  may  extend 
to  the  jaw,  causing  large  abscesses  and  infection  of  the  lymiohatic  glands. 
Abscesses  of  this  character  in  the  lower  jaw  often  burrow  downward  into 
the  tissues  of  the  neck,  involving  the  imjjortant  vessels  of  this  region,  the 
accumulation  of  x^us  being  sometimes  very  considerable.  The  writer  once 
opened  such  an  abscess  from  which  more  than  a  pint  of  pus  was  extracted, 
and  has  frequently  in  his  hospital  practice  treated  cases  in  which  half  that 
quantity  has  been  withdrawn  from  the  abscess. 


80  OPERATIVE    DENTISTRY. 

Septicsemia  and  necrosis  of  the  jaw  sometimes  complicate  the  affection. 
The  presence  of  septicaemia  adds  greatly  to  the  dangers  surrounding  the 
case,  and  may  cause  a  fatal  termination. 

ISTecrosis  of  the  jaw  may  be  of  slight  or  considerable  extent.  It  may 
involve  only  a  portion  of  the  alveolar  process  or  extend  to  the  body  of  the 
bone,  destroying  large  portions  of  it,  or  even  the  entire  half  of  the  jaw. 

The  process  of  eruption  of  the  permanent  teeth  is  so  nearly  analogous  to 
that  of  the  temporary  dentition  that  no  special  description  seems  necessary. 

Irregularities  in  the  Position  of  the  Permanent  Teeth. — In  the 
eruption  of  the  succedaneous  teeth — those  which  succeed  the  deciduous  set — 
rapid  resorption  of  bone  takes  place  upon  the  labial  and  buccal  aspects  of 
their  crypts,  resulting  in  an  opening  very  much  larger  than  the  crown  of 
the  tooth.  The  fact  will  therefore  be  recognized  that  any  slight  mechanical 
obstruction  situated  in  the  path  of  its  progression  would  be  sufficient  to 
deflect  it  from  its  normal  course  and  result  in  an  irregularity  in  position. 
The  muscular  action  of  the  lips  and  tongue,  the  habits  of  tongue-sucking 
and  thumb- sucking,  are  all  potent  factors  in  modifying  the  arrangement  of 
the  teeth  when  applied  at  this  period  of  their  evolution.  Certain  develop- 
mental conditions  of  the  bones  of  the  face  are  very  common  causes  of  irreg- 
ular arrangement  of  the  permanent  teeth,  and  by  some  authorities  thought 
to  be  the  most  prolific  causes, — namely,  excessive  development  and  ar- 
rested or  retarded  development  of  the  maxillary  bones.  These  conditions 
may  be  the  result  of  many  and  varied  causes,  some  hereditary,  others  ac- 
quired.    These  may  again  be  divided  into  constitutional  and  local. 

Among  the  constitutional  conditions  which  may  be  classed  as  direct 
inherited  causes  are,  first,  constitutional  taints,  like  syphilis,  tuberculosis, 
and  neurotic  conditions,  peculiarities  in  the  formation  of  the  jaws  and  of 
the  teeth,  peculiarities  in  the  arrangement  of  the  teeth  in  the  arch,  and 
tendencies  to  the  suppression  of  certain  teeth,  or  to  the  presence  of  super- 
numerary teeth ;  second,  conditions  which  may  be  classed  as  indirect  in- 
herited causes,  as,  for  instance,  when  one  peculiarity  is  inherited  from  the 
father  and  another  from  the  mother,  which  combined  form  an  irregularity, 
like  the  inheritance  of  large  teeth  from  one  parent  and  a  small  jaw  from 
the  other.  The  deformity  is  not  directly  inherited  from  either  parent,  but 
indirectly  from  both. 

Miscegenation  of  nations  and  distinct  races  is  often  a  prolific  source 
of  malformations  of  the  jaws  and  of  irregularities  of  the  teeth,  which  oper- 
ates by  mixing  national  and  race  peculiarities  which  are  more  or  less 
antagonistic  to  each  other.  Third,  acquired  constitutional  defects.  These 
result  from  diseases  or  traumatisms  which  interfere  with  nutrition,  and  thus 
prevent  a  normal  development  of  the  maxillary  bones  and  the  teeth,  or 
cause  an  abnormal  arrangement  of  the  teeth  in  the  alveolar  arches. 

The  local  conditions  which  may  act  as  factors  in  producing  an  abnormal 
arrangement  of  the  teeth  are  : 

1.  Undue  retention  of  the  deciduous  teeth  or  parts  of  a  tooth. 

2.  The  presence  of  supernumerary  teeth. 

3.  The  too  early  extraction  of  the  deciduous  teeth. 

4.  Injudicious  extraction  of  permanent  teeth. 


ERUPTION    OF    THE    TEETH.  81 

5.  Delayed  eruption  of  a  permanent  tooth. 

6.  Moutli-breathing  dne  to  enlarged  tonsils  and  adenoid  growths  in  the 
nasopharynx. 

7.  The  habits  of  tongue-sucking  and  thumb-sucking. 

The  retention  of  a  deciduous  tooth  beyond  the  normal  period  of  its  exuviation 
is  often  productive  of  a  maliDOsition  of  the  succeeding  teeth.  ISTature  pro- 
vides for  the  resorj)tion  of  the  roots  of  deciduous  teeth.  Death  of  the 
pulp  prevents  physiologic  resorption,  therefore  the  unabsorbed  root  of 
the  retarded  tooth  may  cause  the  permanent  tooth  to  be  deflected  from  the 
normal  position. 

The  presence  of  a  supernumerary  tooth  may  also  operate  in  a  like  manner 
to  deflect  the  permanent  tooth  from  a  proper  position  in  the  arch,  or  so 
crowd  the  arch  by  its  presence  as  to  destroy  the  occlusion. 

The  too  early  extraction  of  the  deciduous  teeth  tends  to  retard  the  inter- 
stitial growth  of  the  jaw  ;  permits  the  teeth  upon  either  side  of  the  space 
made  by  the  extraction  of  the  deciduous  tooth  to  move  or  tilt  towards  each 
other,  thus  robbing  the  permanent  tooth  of  its  required  space,  and  forcing 
it  into  an  abnormal  position,  while  the  extraction  of  the  second  deciduous 
molar  before  the  first  permanent  molar  is  erupted  permits  this  tooth  when 
erupted  to  move  forward  and  occupy  the  sj)ace  needed  by  the  second 
bicuspid.  This  procedure  also  induces,  as  graphically  shown  by  Talbot, 
a  shortening  of  the  arch  of  the  jaw  upon  that  side,  thus  crowding  the 
cuspid  and  bicuspids  out  of  line,  and  causing  a  deformity  difficult  to 
remedy  except  by  the  extraction  of  one  of  the  bicuspids. 

The  injudicious  extraction  of  permanent  teeth  often  entails  a  serious  incon- 
venience to  the  individual  by  permitting  a  tilting  of  the  crowns  of  the 
proximate  teeth  and  forming  large  inverted  V-shaped  spaces  which  are 
difficult  to  cleanse,  and  therefore  invite  caries.  This  condition  frequently 
follows  the  extraction  of  the  first  permanent  molar  if  delayed  until  after 
the  eruption  of  the  second  molar. 

The  extraction  of  the  permanent  superior  lateral  incisors,  to  make  room 
for  prominent  cuspids,  also  causes  a  deformity  in  the  arrangement  of  the 
teeth  which  cannot,  except  in  rare  instances,  be  corrected,  and  should  be 
condemned  in  the  severest  terms. 

The  extraction  of  the  cuspids  is  also  to  be  condemned  if  performed  for 
any  other  reason  than  a  diseased  condition  involving  contiguous  parts. 
The  loss  of  the  superior  cuspids  is  productive  of  a  narrowing  of  the  ante- 
rior portion  of  the  arch,  and  depression  at  the  corners  of  the  mouth  and 
alse  of  the  nose. 

Delayed  eruption  of  a  permanent  tooth,  particularly  the  superior  lateral 
incisors  and  the  first  or  second  bicuspids,  are  often  productive  of  trouble- 
some irregularities.  Delayed  eruptions  of  the  lateral  incisor  permits  the 
cuspid  to  take  an  abnormal  forward  position,  often  approximating  the 
distal  surface  of  the  central  incisor,  and  making  it  imj)ossible  for  the 
lateral  to  occujDy  a  normal  position  ;  while  the  non-eruption  of  a  bicuspid 
permits  the  approximation  of  the  contiguous  teeth,  and  often  destroys  the 
occlusion  upon  that  side. 

Mouth-breathing,  due  to  enlarged  tonsils  and  adenoid  growths  in  the  naso- 

6 


82  OPERATIVE    DENTISTRY, 

pharynx,  is  also  productive  of  a  narrowing  of  the  superior  alveolar  arch  in 
the  region  of  the  bicuspids  and  protrusion  of  the  anterior  teeth.  The  writer 
is  aware  that  in  making  this  statement  he  places  himself  in  opposition  to 
some  of  the  very  best  authorities  upon  the  etiology  of  dental  irregularities, 
but  nevertheless  he  believes  that  the  position  of  the  upper  lip  and  of  the 
cheeks,  when  the  mouth  is  open  sufdciently  to  permit  these  subjects  to 
breathe  with  comfort,  is  such  that  steady  and  continuous  pressure  is 
brought  to  bear  ui)on  the  teeth  and  alveolar  process  in  the  bicuspid  region. 
This  force  acting  upon  the  crowns  of  the  erupting  permanent  teeth,  which 
as  yet  have  their  roots  but  partially  formed,  and  have  no  bony  support 
except  the  crypt  in  which  they  have  been  developed,  and  in  this  resorp- 
tion of  the  walls  has  been  so  considerable  that  the  opening  in  it  is  much 
larger  than  the  size  of  the  crown,  while,  furthermore,  the  alveolar  process 
is  not  formed  around  these  teeth  until  after  the  crown  is  erupted,  cannot 
but  exert  a  moulding  influence  upon  the  iDOsition  of  these  teeth  and  their 
alveolar  process,  narrowing  the  arch  at  this  portion  and  protruding  the 
teeth  in  the  incisive  region.  It  seems  to  the  writer  that  if  these  facts  in 
relation  to  the  evolution  of  the  teeth  and  alveolar  process  are  given  their 
full  weight  in  the  argument,  it  must  be  acknowledged  that  mouth-breathing 
is  as  potent  a  factor  in  the  production  of  this  class  of  irregularities  as  that 
they  are  produced  by  an  arrested  or  retarded  development  of  the  jaws, 
caused  by  the  obstruction  of  nasal  breathing. 

The  habits  of  tongue- sucking  and  thmnh-sucldng  may  also  be  regarded  as 
factors  in  the  production  of  protrusion  of  the  anterior  teeth.  Sucking  of 
the  tongue  may,  by  the  pressure  upon  the  lingual  surfaces  of  the  superior 
and  inferior  incisors,  cause  a  protrusion  of  the  teeth  of  both  jaws.  While 
sucking  of  the  thumb  may  cause  a  protrusion  of  the  superior  incisors  by 
the  pressure  upon  their  lingual  surfaces,  and,  when  the  thumb  also  presses 
upon  the  labial  surfaces  and  morsal  edges  of  the  Inferior  incisors,  it  may 
cause  an  intrusion  of  these  teeth.  These  habits  do  not,  as  a  rule,  cause 
irregularities  of  the  deciduous  teeth.  This  fact  has  been  used  as  an  argu- 
ment against  the  possibility  of  their  causing  a  malposition  of  the  perma- 
nent teeth.  At  first  the  argument  seems  good,  but  upon  a  careful  study 
of  the  facts  and  conditions  it  will  be  discovered  that  these  habits  are  rarely 
confirmed  in  the  child  until  about  the  time  that  it  is  weaned  from  the 
breast  or  the  bottle,  which  generally  occurs  when  the  child  is  from  one 
and  one-half  to  two  years  of  age. 

The  roots  of  the  deciduous  incisors  are  at  this  time  nearly  or  fully 
formed,  and  the  development  of  the  alveolar  processes  is  completed,  thus 
rendering  the  teeth  fairly  stable  and  not  easily  moved  from  their  posi- 
tion by  such  a  form  of  intermittent  pressure,  while,  upon  the  other  hand, 
when  the  habits  are  continued  to  the  period  of  the  eruption  of  the  per- 
manent incisors,  it  can  be  readily  understood  how,  during  the  passage  of 
the  crowns  of  these  teeth  through  the  gums,  and  during  the  development 
of  their  roots  and  of  the  alveolar  processes,  a  very  slight  amount  of 
pressure,  even  though  of  an  intermittent  character,  would  be  sufficient  to 
divert  them  from  their  normal  position  to  an  abnormal  protrusion  of 
greater  or  less  obliquity. 


CHAPTEE    Y. 

BACTERIOLOGY   OF   THE   MOUTH. 

The  discoveries  wliicli  the  science  of  bacteriology  has  made  and  ia 
still  making  in  reference  to  the  causation  of  disease  render  it  imperative 
that  a  knowledge  of  the  bacteriology  of  the  mouth  should  be  possessed  by 
the  student  and  the  practitioner  who  would  ai3i)roach  a  scientific  study  of 
dental  and  oral  diseases^  or  who  would  be  successful  in  their  treatment. 

Bacteriology  is  one  of  the  most  exact  of  the  medical  sciences,  and  is 
governed  by  the  most  rigid  laws,  the  slightest  deviation  from  which  often 
vitiating  the  results  of  long  and  laboriously  conducted  experiments. 

The  student,  therefore,  who  would  hope  to  do  original  work  in  this 
line  will  need  to  cultivate  exactness  in  methods  and  the  most  scrupulous 
obedience  to  those  laws  which  have  been  found  to  govern  the  various 
phenomena  of  their  natural  and  artificial  growth,  and  the  methods  by 
which  their  various  functions  may  be  proved. 

1^0  treatise  on  operative  dentistry  written  at  the  present  day  can  be 
considered  as  at  all  complete  which  does  not  deal,  to  some  extent  at  least, 
with  the  subject  of  oral  bacteriology  ;  yet  in  a  treatise  of  this  size  it  will 
not  be  possible  to  give  more  than  a  simple  outline  of  the  subject  in  gen- 
eral, and  this  of  necessity  must  be  more  or  less  elementary  in  character. 

Definition. — The  term  bacteriology  is  derived  from  the  Greek  paKrr/piov, 
a  little  stick,  and  ?.6yog,  science. 

Bacteriology  is  that  department  of  biology  which  deals  with  the  origin, 
development,  and  functions  of  living  micro-organisms. 

With  the  development  of  the  science  of  bacteriology,  or  rather  out  of  it, 
has  grown  the  germ  theory  of  disease.  This  theory,  when  first  promulgated, 
had  for  its  foundation  the  demonstrable  facts  that  a  certain  few  diseases  were 
caused  by  specific  germs,  micro-organisms,  or  parasites.  These  statements 
of  fact  stimulated  further  research  into  the  causation  of  other  diseases, 
many  of  which,  both  medical  and  surgical,  were  found  to  be  dependent 
upon  specific  micro-organisms  which  had  gained  access  to  the  tissues  of 
the  body. 

These  discoveries  have  revolutionized  the  practice  of  medicine  and 
surgery  in  all  their  departments,  but  the  greatest  revolution  has  been  in 
the  practice  of  surgery. 

"Without  the  discovery  of  the  pyogenic  bacteria  and  of  the  other  path- 
ogenic forms  now  known  to  science,  and  without  a  knowledge  of  the  i)rin- 
ciples  of  modern  antiseptics  which  grew  out  of  these  discoveries^  much 
of  the  success  which  has  been  achieved  in  modern  surgery  during  the  last 
two  decades  would  still  be  an  impossibility. 

The  achievements  in  modern  dental  surgery  in  the  prevention  and 
treatment  of  oral  diseases  have  been  due  to  the  discoveries  made  in  oral 


84  OPERATIVE    DENTISTRY. 

bacteriology  and  to  the  application  of  the  same  general  principles  of  anti- 
septics. 

PARASITES. 

Definition. — Parasites  are  plants  or  animals  which  live  npon  other 
plants  or  animals. 

In  the  early  history  of  bacteriology  scientists  found  great  diflaculty  in 
classifying  some  of  the  parasitic  forms,  from  the  fact  that  it  was  almost . 
impossible  to  determine  whether  they  belonged  to  the  animal  or  vegetable 
kingdom.  Nearly  all  of  the  parasites  which  enter  the  animal  organism  are 
microscopic  in  size^  hence  they  have  been  designated  as  micro-organisms, 
microbes,  or  bacteria.  Scientists  are  now  generally  agreed  in  classifying  the 
bacterial  forms  as  belonging  to  the  vegetable  kingdom.  Bacteria  belong 
to  the  fission  plants,  known  as  ScMzoi^hyta  or  ScMzopliytes,  a  division  of  the 
Thallojyhi/fa,  including  those  varieties  which  multiply  hj  fission  or  division. 
These  are  divided  into  two  sub-classes,  those  which  possess  chlorophyll — 
namely,  the  Cyanophycew  (usually  referred  to  as  Algce) — and  those  having 
no  chlorophyll,  or  the  ScJiizomycetes  (usually  referred  to  as  Fungi). 

''Many  of  the  bacterial  forms  are  so  small  as  to  approach  the  limits  of 
visibility,  even  when  the  highest  powers  of  the  microscope  are  employed." 
When  located  in  the  animal  tissues,  they  are  often  demonstrated  with  the 
greatest  difficulty,  special  staining  reagents  being  necessary — sometimes 
double  and  triple  staining  being  required — to  differentiate  them  from  the 
cellular  elements  of  the  tissues ;  even  then  the  demonstration  may  be 
unsatisfactory,  and  it  becomes  necessary  to  institute  a  series  of  experi- 
mental cultivations  of  the  products  of  tissue  disintegration  in  the  case, 
and  the  inoculation  of  lower  animals  with  the  products  of  the  artificial 
cultivations  before  a  positive  diagnosis  can  be  reached. 

Miller,  in  his  "Micro-organisms  of  the  Human  Mouth"  (1882),  ar- 
ranged those  fungi  which  have  a  bearing  upon  the  hygienic  conditions  of 
the  body  into  four  groups  : 

1 .  Fission  fungi  (bacteria)    Schizomyceies. 

2.  Mould  or  thread  fungi Hyphomyceles. 

3.  Bud  fungi  (j^east  fungi ) Blastomycetes. 

4.  Animal  fungi  (Pilzthiere) Mycetozoa. 

The  first  of  the  four  groups,  the  Fission  fimgi,  are  the  most  important 
from  the  stand-point  of  health  and  disease,  as  they  are  the  chief  agents  in 
the  production  of  fermentations  and  putrefactions,  and  although  through 
these  i)rocesses  they  conserve  the  life  and  health  of  the  vegetable  and  of 
the  animal  kingdom,  by  preventing  the  accumulation  ui3on  the  earth's 
surface  of  dead  vegetable  and  animal  matter,  reducing  them  to  their  origi- 
nal elements  and  returning  them  again  to  the  air,  the  water,  and  the 
earth,  they  unfortunately  have  the  power  of  attacking  living  organisms 
and  exerting  most  baneful  influences  upon  health  and  life,  and  are  now 
recognized  as  being  the  active  or  exciting  cause  of  a  very  large  number  of 
the  diseases  which  attack  the  human  body. 

The  mould  fungi  (Fig.  226),  although  widely  distributed  in  nature,  have 
much  less  importance  from  the  hygienic  stand-point.     They  produce  de- 


Fig.  22H.— Fruit  iiiDulil.     (Shearer.)     X  1^0. 


^i 


f-'^-        -« 


Fin.  229.— Torula,  or  veast  fungi. 


BACTERIOLOGY    OF    THE    MOUTH. 


85 


compositions  of  organic  substances,  but  with  less  intensity,  and  with  the 
exception  of  certain  cutaneous  diseases,  thrush  and  ringworm,  do  not 
cause  such  profound  disturbances  in  the  human  body  as  do  the  fission 
fungi,  although  abscesses  and  seropurulent  peritonitis  have  been  known 
to  occur  from  inoculation. 

The  hud  fungi  are  even  less  important  as  disease-producers  than  the 
mould  fungi.  About  the  only  diseases  known  to  be  produced  by  them  are 
blastomycetic  dermatitis  and  certain  catarrhal  changes. 

Fig.  227. 


®Tee« 


.  Forms  of  bacteria.  (In  part  after  Fliigge  and  Zopf.)  a,  cocci ;  b,  diplococci ;  c,  cluster-cocci  (staphy- 
lococci) ;  d,  coccus  chains  (streptococci,  torula) ;  e,  surface-shaped  colonies  (merismopedia) ;  /,  packet- 
shaped  colonies  (sarcina) ;  g,  a  double  coccus  chain  produced  by  a  single  fissation  of  each  member  in 
a  direction  at  right  angles  to  the  long  axis  of  the  chain ;  h,  vibriones ;  i,  k,  spirilla ;  I,  spirochsetes ; 
m,  spiromonades  ;  n,  spirulina;  o,  cladothrix  ;  p,  rods  (bacilli) ;  q,  Clostridium  ;  r,  leptothrix  (threads) ; 
r',  articulated  threads  ;  s,  rhabdomouas  ;  t,  u,  v,  zooglcea. 


The  animal  fungi,  or  mycetozoa,  are  a  group  of  fungus-like  saprophytic 
organisms,  the  slime  fungi  or  slhne  moulds.  Most  naturalists  and  bacteriol- 
ogists class  them  as  fungi  or  as  plant-growths  of  low  type.  E.  E.  Lankes- 
ter  and  his  followers,  however,  group  them  with  the  protozoa,  or  lowest 
animal  forms,  while  others  have  classed  them  as  protists,  or  living  organ- 
isms not  decisively  classifiable  as  either  plants  or  animals. 

Of  the  animal  fimgi,  mycetozoa,  or  slime  moulds,  very  little  is  known. 
These  organisms  resemble  huge  masses  of  protoplasm,  which  are  found 


86 


OPERATIVE    DENTISTRY. 


upon  decaying  vegetable  matter.  They  are  the  supposed  origin  of  certain 
plant  diseases,  such  as  the  "  finger  and  toe"  of  cabbage  roots. 

Bacteria  are  divided  into  three  general  classes  according  to  their  form, 
—viz.,  spherical  cells,  rod  forms,  and  screw  forms.  Those  which  are  rod- 
shaped  are  termed  bacilli;  those  which  are  spherical  are  designated  as 
cocci  or  sphero-hacteria ;  while  those  with  screw  forms  are  called  sjnrilla. 

Fig.  227  represents  some  of  the  common  forms  of  bacteria. 


zopf's  classification  (modified). 

Group  I.  Coccace?e.     Spherical  forms  only. 

Genus  I.  Micrococcus  (Staphylococcus)  Division  in  one  direction  only, 
but  irregular,  so  that  the  cocci  after  division  form  irregular  clus- 
ters. 
Genus  II.   (Streptococcus)  Division  in  one  plane,  but  regular,  so  that 

the  cocci  form  chains. 
Genus  III.  Division  in  three  directions  at  right  angles  to  each  other, 
and  in  two  j^lanes,  so  cubes  are  formed. 
Group  II.  Rods,  straight  or  curved.     At  some  period  of  life  history, 
though  cocci  and  other  forms  may  occur. 
Genus  I.  Bacterium.     Straight  rods  ;    endospore  formation  does  not 

occur. 
Genus  II.  Bacillus.     Straight  rods  ;  endospore  formation  occurs. 
Genus  III.  Spirillum.     Spiral  rods  ;  spore  formation  does  not  occur. 
Genus  IV.  Yibrio.  Spiral  rods  ;  spore  formation  occurs. 
Group  III.  Leptotrichee.     These  are  all  thread  forms. 
This  is  a  practical  and  convenient  classification. 

Pasteur  classified  all  bacteria  under  two  general  divisions,  from  their 
relations  to  oxygen  ;  one  division  he  termed  Aerobes,  the  other  Anaerobes. 

The  aerobic  bacteria  require 
Fi-G.  228.  the  oxygen  of  the  atmosphere 

in  order  to  maintain  existence, 
and  therefore  live  ui)on  the  sur- 
faces of  substances. 

The  yeast  fungi  are  examples 
of  aerobic  bacteria  (Fig.  228). 

Fig.   229  shows   one  of  the 
forms  of  yeast  fungi — the  torula. 
The  anaerobic  bacteria  do 
not  require  oxygen  to  maintain 
existence,  hence  they  live  be- 
neath  the   surfaces   of   liquids 
and  within  the  tissues  of  living 
bodies.     The  Bacterium  tetani  is 
an   example   of  the  anaerobic 
bacteria  ;  oxygen  retards  its  growth  or  completely  arrests  its  development. 
A  very  large  proportion  of  all  the  bacteria  are  aerobic.     Some  of  them 
are  so  dependent  upon  oxygen  that  even  the  slightest  diminution  in  the 


Various  forms  of  yeast  fungi,  a,  colonies  of  round 
cells  (saccharomyces  conglomeratus?) ;  b,  single  cells  of 
different  forms  partly  forming  daughter-cells ;  c,  cylin- 
drical cells  of  the  pellicle  fungus  (saccharomyces  myco- 
derma). 


BACTERIOLOGY   OF   THE    MOLTH.  87 

amount  is  sufficient  to  retard  or  completely  arrest  their  development. 
These  are  termed  obligate  aerobic  bacteria.  Others  will  develop  equally 
well  in  a  medium  rich  in  oxygen,  or  where  there  is  no  oxygen,  or  rather, 
independent  of  the  atmosphere.  These  are  called  facultative  aerobic  bac- 
teria. Nearly  all  the  disease-producing  forms  of  bacteria  belong  to  the 
facultative  variety.  The  fluids  and  tissues  of  the  body  contain  a  certain 
amount  of  oxygen,  but  this  is  soon  consumed  by  the  rapid  growth  and 
multix^lication  of  the  bacteria ;  consequently  their  development  would  be 
arrested  or  their  existence  terminated  did  they  not  possess  the  faculty  of 
living  under  certain  conditions  without  the  presence  of  oxygen. 

^'  The  capability  of  certain  bacteria  to  proliferate  and  to  manifest  their 
specific  action  without  access  of  air  may  explain  the  progress  of  tooth  caries 
under  air-tight  fillings  in  cases  where  the  softened  dentin  was  not  thoroughly 
removed  before  inserting  the  filling."     (Miller.) 

Long  exposure  of  certain  forms  of  pathogenic  bacteria  to  oxygen 
diminishes  their  virulence.  Pasteur  discovered  that  if  artificial  cultures 
were  made  of  the  bacterium  of  chick  en -cholera  and  the  cultures  exposed 
to  oxygen  for  a  period  ranging  from  three  to  eight  months,  the  virus  be- 
came very  much  attenuated.  Cultures  of  the  anthrax  bacillus  when 
treated  in  a  like  manner  gave  the  same  i-esults. 

He  found  that  if  a  chicken  was  inoculated  with  this  weakened  or  atten- 
uated culture  of  the  chicken-cholera  bacillus,  it  was  rendered  immune  to 
the  action  of  the  virulent  virus,  and  that  the  attenuated  culture  of  the 
anthrax  bacillus  prepared  in  the  same  manner  rendered  sheep  immune  to 
inoculations  with  anthrax,  or  if  the  disease  was  contracted  after  inocula- 
tion with  the  attenuated  virus,  it  appeared  in  only  a  very  mild  form, 

Paul  Bert  has  discovered  that  if  the  anthrax  bacillus  is  exposed  to 
oxygen  under  a  pressure  of  twenty  to  forty  centimetres,  its  vitality  is  com- 
pletely destroyed. 

Functions  of  Bacteria. — Bacteria  are  often  classified  according  to 
their  particular  function ;  for  instance,  certain  species  are  disease-pro- 
ducing ;  these  are  tevvn^ii  pathogenic.  Other  varieties  produce  color, — yel- 
low, white,  green,  etc.  ;  these  are  designated  as  chromogenic.  Another 
species  causes  fermentation,  and  are  called  zymogenic.  Another  produces 
gas  ;  these  are  termed  aerogenic.  Others  are  endowed  with  intense  putre- 
factive properties  and  are  known  as  saprogenic,  while  many  others  have 
not  yet  had  their  special  functions  discovered. 

A  very  large  proportion  of  the  bacterial  forms  are  saprogenic. 

When  classifying  bacteria  according  to  their  relations  to  disease,  it  is 
customary  to  arrange  them  under  two  general  divisions  : 

1.  Non-pathogenic,  or  those  which  do  not  as  a  direct  cause  produce 
disease. 

2.  Pathogenic,  or  those  which  are  the  direct  cause  of  disease. 

Fermentation  and  putrefaction  are  the  results  of  the  growth  and  multi- 
plication of  certain  forms  of  bacteria  within  the  substances  which  ferment 
or  putrefy. 

Among  the  non-pathogenic  micro-organisms  are  included  the  sapro- 
phytic germs.     These  are  sometimes  spoken  of  as  "nature's  scavengers," 


88  OPERATIVE    DENTISTRY. 

from  the  fact  tliat  they  prey  upon  dead  and  decomposing  vegetable  and 
animal  matter.  These  organisms  may  become  indirect  causes  of  disease 
when  they  gain  access  to  wounds  in  which  there  are  pent-up  discharges  and 
dying  tissues.  Under  such  circumstances  they  propagate  with  great 
rapidity,  and  produce  certain  poisonous  and  irritating  substances  called 
ptomaines,  which  when  absorbed  by  the  system  give  rise  to  symptoms  which 
are  denominated  as  sejMc  intoxication,  ptomaine  fever,  or  septiccemia. 

Such  conditions  may  follow  the  death  of  a  tooth-pulp,  the  extraction  of 
a  tooth,  the  wounding  of  the  tissues  of  the  mouth,  or  a  compound  frac- 
ture of  the  jaw. 

Pathogenic  micro-organisms  grow  and  flourish  in  the  dead  and  dying 
matter,  and  invade  the  living  tissues  and  destroy  them.  They  also  enter 
the  circulation  by  direct  inoculation  through  wounds  and  abrasions,  and 
are  carried  to  all  parts  of  the  body,  and  wherever  deposited  increase  in 
numbers  with  amazing  rapidity,  forming  fresh  foci  for  the  production  of 
poisonous  and  irritating  substances.  The  chief  difference,  therefore,  be- 
tween the  saprophytes  and  the  pathogenic  germs  is,  that  the  former  act  as 
indirect  causes  of  disease  by  the  production  of  poisonous  substances,  which 
are  absorbed  by  the  system  ;  but  they  have  no  power  to  penetrate  the  tis- 
sues or  to  enter  the  circulation,  while  the  latter  possess  this  power  and  act 
as  direct  disease-producing  agents. 

The  pathogenic  bacteria  may  be  divided  again  into  two  general  classes  : 

First.  Micrococci. 

Second.  Bacilli. 

Each  of  these  classes  has  been  divided  and  subdivided  by  the  bacteri- 
ologist into  an  almost  endless  variety.  This  division  and  subdivision  has 
been  made  necessary  by  the  discoveries  which  have  grown  out  of  the  more 
thorough  and  careful  study  instituted  as  to  their  size,  form,  and  length  ; 
their  growth,  grouping,  and  manner  of  propagation ;  their  action  upon 
the  various  culture-media  ;  their  chemical  reaction  ;  the  color  imparted  to 
the  culture-media  ;  their  susceptibility  to  the  various  staining  reagents,  and 
their  action  uijon  fermentable  substances  and  living  organisms. 

Investigation  is  constantly  going  on,  and  almost  daily  discoveries  are 
being  made  of  new  forms  of  bacteria,  or  "further  research  into  the  life 
and  habits  of  old  forms  develops  new  features  and  modes  of  action,  which 
a  little  while  before  had  not  been  dreamed  of,  while  the  etiology  of  cer- 
tain diseases  which  were  before  considered  as  obscure  are  one  by  one 
being  cleared  up  by  the  discovery  of  a  specific  micro-organism,  which, 
when  introduced  into  the  system  in  sufiBcient  quantities,  will  produce  the 
disease." 

The  evidence  which  has  been  deduced  in  regard  to  the  specific  nature 
of  the  micro-organisms  found  in  anthrax,  typhoid  (Fig.  230),  tuberculosis, 
tetanus,  diphtheria,  glanders,  leprosy,  cholera,  bubonic  plague  (Fig.  231), 
pneumonia  (Fig.  232),  erysipelas,  actinomycosis,  gonorrhoea,  and  suppu- 
rative inflammation  is  beyond  dispute,  while  in  many  other  diseases  the 
evidence  strongly  points  to  the  presence  of  a  specific  germ  as  the  active 
cause  of  their  development. 

The  Micrococcus  is  an  individual  bacterium,  the  smallest  of  all  the  bac- 


~:  .  r'      » 


^ 


Fig.  230.— Barterium  typhosus.    X  1000. 


%  * 


Fig.  281.— Bacillus  testis,  and  blood-cells  of  rat.     :■    1000. 


Fig.  23'2. — Pneumococciis,  showing  capsule  form.     (V.  A.  Latham.)     X  1200. 


KiG.  2o3. — Diploeoccus  pneumoniaB.    (Fraiikel.)      <  1000. 


Fig.  23-1. — Streptococcus  pyogenes.     (V.  A.  Latham.)     X  1000. 


fV  K    i* 


^% 


#      ''  * 


^<»' 


<^^'\i 


•-^ 


Fig.  235. — Streptococcus  in  pysemia  after  erysipelas.     (V.  A.  Latham.)     X  fi60. 


. „^-'',  •  /    *I 


it*t 


c 


•F 


FiG.  236. — Forms  of  bacteria  in  pus  iidin  an  ahscess.      ■'  700.    .1,  jius-cclls ;  B,  micrococci  ami  diplococci; 

C,  streptococci ;  D,  tctracocci. 


"^ 


V 


s/V 


Vi' 


y   1 


^< 


Fig.  'J:',;. — Bacillus  tuberculosis.     X  1000. 


BACTERIOLOGY    OF    THE    MOUTH.  89 

terial  forms,  spherical,  or  nearly  so,  tiny,  globe-like  masses  of  matter,  in 
some  instances  isolated,  in  others  united  in  pairs,  in  fours,  or  in  larger 
numbers,  or  arranged  in  chains  or  chaplets,  or  deposited  in  masses  of 
zooglea  or  gelatinous  matrix  secreted  by  the  bacteria  themselves. 

When  the  micrococci  are  united  in  pairs  they  are  termed  Diplococci 
(Fig.  227,  B)^  when  in  fours,  Tetracocci  (Fig.  227,  D).  When  grouped  in 
clusters  they  are  called  Staphylococci.  When  arranged  in  chains  or  chaplets 
they  are  known  as  Streptococci  (Fig.  227,  C). 

The  pneumococcus  or  diplococcus  of  pneumonia  (Fig.  233)  is  a  good  rep- 
resentation of  the  diplococci. 

Among  the  numerous  difficulties  which  have  to  be  met  by  the  bacteri- 
ologist and  the  pathologist  is  the  seeming  identity  of  certain  forms  of  bac- 
teria found  in  diseases  presenting  dissimilar  characteristics  ;  for  instance, 
the  Streptococcus  pyogenes  (Fig.  234)  seems  to  be  identical  with  the  Strepto- 
coccus erysipelatus  (Fig.  235),  the  only  discoverable  difference  being  one 
of  size,  the  coccus  of  erysipelas  being  the  larger. 

The  cocci  multiply  or  propagate  only  by  fission.  The  cell  elongates 
prior  to  its  segmentation,  when  a  constriction  appears  in  the  centre,  which 
becomes  deeper  and  deeper  until  complete  division  of  the  cell  into  two 
equal  parts  takes  place.  These  new  cells  soon  attain  the  size  of  the  parent 
cell,  when  they  divide  in  the  same  manner,  and  so  on  ad  infijiitum. 

The  diplococci,  staphylococci,  and  streptococci  are  generally  found 
associated  with  broken-down  tissue  and  discharges  which  result  from  in- 
flammatory action,  particularly  in  the  pus-formations  of  acute  abscesses 
and  suppurating  wounds  (Fig.  236).  These  are  termed  the  pyogenic  cocci, 
or  pus-microhes. 

The  bacillus  is  an  individual  bacterium  of  rod-like  form.  The  bacilli 
include  all  of  the  elongated  forms  of  bacteria,  except  the  screw  forms,  and 
such  as  have  a  gyratory  motion  ;  these  are  classed  with  the  genus  Spiril- 
lum. The  bacillus  tuberculosis  (Fig.  237)  is  a  good  example  of  the  short 
rod-like  bacilli. 

A  spirillum  is  an  individual  bacterium  whose  elements  are  curved,  often 
forming  a  spiral  of  several  turns.  Koch's  comma  bacillus,  which  is  found  in 
the  alvine  discharges  of  patients  suffering  from  Asiatic  cholera,  is  a 
spirillum,  and  represents  a  simj^le  curved  variety,  while  Miller'' s  spiril- 
lum, which  is  found  in  carious  teeth,  represents  the  screw  or  spiral  form. 
Some  of  the  spirilla  have  flagella  attached  to  their  extremities  (Fig.  238.) 
The  bacillus  of  hog  cholera  is  an  excellent  illustration  of  a  flagellated 
bacillus  (Fig.  239). 

Some  bacilli  are  rigid,  others  flexible  ;  some  are  motile,  others  non- 
motile,  and  they  propagate  either  by  direct  fission  or  by  endogenous 
spore-formation, — the  formation  of  a  cell  within  the  body  of  the  parent 
cell. 

Multiplication  of  Bacteria. — -The  process  of  reproduction  in  bacteria 
is  a  very  rapid  one.  Fliigge  observed  the  process  of  segmentation  in  a 
coccus  to  be  completed  in  twenty  minutes.  Cohn  has  made  the  calcula- 
tion that  if  it  should  take  one  hour  to  complete  the  process  of  segmentation 
and  for  the  new  cell  to  attain  the  size  of  the  parent-cell,  one  coccus,  mul- 


90  OPERATIVE    DENTISTRY. 

tiplying  by  this  process,  would  in  a  single  day  produce  16,000,000 
progeny  ;  at  the  end  of  two  days  281,000,000,000  ;  while  at  the  end  of  the 
tliird  day  it  would  have  reached  the  enormous  number  of  46,000,000,000,000. 
Such  figures  are  at  first  thought  very  startling,  and  if  this  multiplication 
could  go  on  unhindered,  the  earth  might  soon  be  dominated  by  micro- 
organisms. There  are,  however,  many  circumstances  which  constantly 
oppose  them  ;  one  of  the  chief  of  these  is  their  own  delicate  susceptibility 
to  change  of  environment,  the  slightest  difference  in  the  soil,  amount  of 
oxygen,  temperature,  or  moisture  being  sufficient  in  many  instances  to 
arrest  their  growth  or  completely  destroy  them. 

Various  species  are  found  growing  together,  but  the  struggle  for  ex- 
istence and  of  natural  selection  is  as  active  here  as  elsewhere  5  the  stronger 
and  more  vigorous  soon  destroy  the  weaker.  When  they  enter  healthy 
living  bodies  they  are  attacked  by  the  phagocytes  and  destroyed,  or  they 
do  not  find  a  congenial  soil  in  which  to  grow,  and  either  die  or  are  swept 
out  of  the  body  by  the  excretory  organs. 

The  sjyore  possesses  an  exceedingly  dense  enveloping  membrane,  which 
protects  it  from  harmful  external  influences  until  such  time  as  it  finds  a  soil 
and  environment  suitable  for  its  growth  and  propagation. 

The  iDarent  cell  is  usually  enlarged  at  the  middle  or  at  one  end  by  the 
growth  of  the  spore,  and  when  it  reaches  its  full  development  gelatinous 
softening  of  the  cell-membrane  takes  place,  the  cell  breaks  up,  and  the 
spore  is  set  free.  The  spore  loses  its  tough  enveloping  membrane  during 
its  process  of  development,  and  is  therefore  more  readily  destroyed. 

The  struggle  for  existence  between  certain  species  of  bacteria  found 
growing  together  suggested  a  therapeutic  principle,  the  overcoming  of  one 
pathogenic  species  by  the  introduction  of  another,  which  many  investi- 
gators have  been  trying  to  utilize  for  the  benefit  of  mankind,  though  as 
yet  with  only  loartial  success.  Blood-serum  therapy,  however,  is  making 
rapid  advances,  and  gives  promise  of  being  the  most  successful  method  of 
preventing  or  curing  those  diseases  which  are  due  to  the  introduction  of 
micro-organisms  into  the  system,  or  of  their  poisonous  products. 

The  growth  of  bacteria  is  also  influenced  by  the  presence  of  their  own 
excretory  or  waste  products ;  for  instance,  the  yeast  plant  ceases  to  grow 
after  a  certain  amount  of  alcohol  has  been  formed. 

The  ammoniac  fermentation  of  urine  ceases  when  the  ammonium  car- 
bonate reaches  thirteen  per  cent.     (Fliigge. ) 

In  lactic  acid  fermentation  the  process  ceases  when  the  acidity  has 
reached  0.75  to  0.80  per  cent.,  and  the  micro-organism  is  often  destroyed 
by  the  action  of  the  acid  which  has  been  produced. 

Lactic  acid  fermentation  of  the  carbohydrates  takes  place  spontaneously 
in  milk,  in  the  juice  of  the  sugar-beet,  in  the  accumulations  in  the  oral 
cavity,  etc.,  and  may  be  artificially  induced  by  a  large  number  of  different 
bacteria  in  saccharine  solutions.     (Miller. ) 

Acids  and  cdMlies  possess  a  certain  amount  of  controlling  influence  in 
the  growth  of  bacteria,  especially  the  former.  Acids  in  very  dilute  solu- 
tion retard  the  development  of  bacteria.  There  are,  however,  important 
exceptions  to  this  rule,  as,  for  instance,  the  Mycoderma  aceti — acetic  acid 


J'lrt^ellateii  ^pinllse  aiKi  vihno.     ,    21G0. 


/ 


^;>x.\' 


Fig.  289.— Bacillus  of  hog  cholera.     (V.  A.  Latham.)     x  1000. 


a- 


^         ^ 


4^  ^^ 


Fig.  240.— Staphylococcus  pyogenes.     (V    A.  Latham.) 
X  1000. 


Fig.  241. — Streptococcus  pyogenes.     ;<  1000. 


4>.%^ 


Fig.  242.— Streptococcus  hominis.     (V.  A.  Latham.)     X  218.75. 


BACTEEIOLOGY    OF    THE    MOUTH.  91 

bacterium — thrives  best  in  a  solution  containing  an  excess  of  from  one  to 
two  per  cent,  of  acetic  acid.  Ten  per  cent,  of  acetic  acid  prevents  tlie 
continuation  of  the  acetic  acid  fermentation,  while  the  Micrococcus  urea 
thrives  best  in  a  high  degree  of  alkalinity.  With  few  exceptions,  how- 
ever, a  neutral  medium  is  best  adajDted  for  the  growth  and  propagation  of 
micro-  organisms. 

Heat  and  Moisture. — Two  conditions  are  absolutely  necessary  for  the 
germination  and  develoj)ment  of  bacteria, — viz.,  a  certain  amount  of  heat 
and  moisture.  Both  must  be  present,  and  in  suitable  amount ;  the  requi- 
site amount  of  heat  minus  the  moisture,  or  the  moisture  minus  the  heat, 
is  in  neither  case  favorable  to  their  development. 

This  is  eminently  true  in  the  treatment  of  dental  caries  and  devitalized 
teeth  ;  with  thorough  desiccation  of  the  properly  prepared  cavity  of  decay, 
or  of  the  root-canal,  and  the  prevention  of  the  ingress  of  moisture  by  tight 
plugs,  caries  will  be  arrested  in  one  case  and  suppuration  prevented  in  the 
other.  In  no  department  of  surgery  is  thorough  antisepsis  more  imj^ortant 
than  in  operations  upon  the  teeth. 

The  temperature  necessary  for  the  growth  of  the  majority  of  bacteria 
is  37°  C.  (98°  F.).  Mature  bacteria  cannot  resist  a  temperature  of  77°  C. 
(170°  F.).  Most  of  them  are  destroyed  when  exposed  to  a  temperature 
of  55°  C.  (131  F.),  while  spores  have  been  known  to  resist  100°  to 
120°  C.  (212°  to  236°  F.).  A  temperature  of  100°  C.  (212°  F.),  if  main- 
tained for  ten  to  fifteen  minutes,  will  effectually  destroy  the  most  per- 
sistent of  spores. 

Spores  resist  the  action  of  germicidal  agents  to  a  much  greater  degree 
than  the  bacilli  which  produced  them,  doubtless  on  account  of  the  tough 
membrane  which  envelops  them. 

Spores  which  have  gained  access  to  the  tissues  of  the  body  may  remain 
dormant  for  years,  and  give  rise  to  no  untoward  symptoms  until  aroused 
to  activity  by  the  presence  of  conditions — environment — which  favor 
their  development  and  multiplication. 

Fiitterer  reports  having  found  the  typhoid  bacillus  in  the  gall-bladder 
years  after  the  initial  attack  of  tyx^hoid  fever. 

Pyogenic  or  Pus  Bacteria, — The  pathogenic  micro-organisms  with 
with  which  the  surgeon  and  the  dentist  has  most  frequently  to  contend  are 
those  which  cause  suppuration. 

The  pyogenic  bacteria  by  a  specific  action  convert  the  inflammatory 
exudates,  leucocytes,  and  the  cellular  elements  of  the  tissues  into  pus. 
They  are,  therefore,  termed  pyogenic  or  pus  bacteria.  Of  these  there  are 
several  varieties,  most  of  them  of  the  globular  or  coccus  form  (Figs.  240, 
241,  and  242).  The  number  of  bacterial  forms  which  have  been  fully 
identified  as  the  exciting  cause  of  surgical  diseases  is  not  large,  yet  the 
statement  may  be  safely  made  upon  the  basis  of  our  present  knowledge, 
that  all  traumatic  infective  diseases  can  be  traced  to  the  specific  action 
of  certain  micro-organisms  which  have  gained  access  to  the  tissues  of  the 
body. 

Koch  laid  down  certain  laws  which  he  thinks  should  be  used  as  the 
crucial  test  in  establishing  the  specific  disease-iDroducing  power  of  any 


92  OPERATIVE    DENTISTRY. 

given  organism  :  1,  it  must  be  found  in  all  cases  of  that  disease ;  2,  it 
must  be  found  in  no  other  disease ;  3,  it  must  appear  in  such  quantity 
and  be  so  distributed  that  all  symptoms  may  be  accounted  for  by  its 
presence ;  4,  the  organism  musfc  be  capable  of  being  isolated  from  the 
diseased  tissues  and  be  grown  upon  some  artificial  culture-media  ;  5,  when 
injected  into  an  animal  it  must  be  capable  of  reproducing  the  disease. 
In  many  instances  all  of  these  conditions  cannot  be  fulfilled,  yet  when  a 
certain  form  or  variety  of  micro-organism  is  constantly  present  in  a  par- 
ticular disease,  it  is  fairly  good  evidence  that  it  is  the  specific  cause  of 
that  disease,  although  we  may  not  be  able  to  cultivate  it  artificially. 

Pathogenic  Mouth  Bacteria.— To  Professor  Miller  of  the  Univer- 
sity of  Berlin  science  is  indebted  more  than  to  any  other  bacteriologist  for 
our  knowledge  of  the  mouth  bacteria. 

This  author  has  shown  in  his  most  valuable  work,  the  ''  Micro-organ- 
isms of  the  Human  Mouth,"  that  nearly  all  of  the  pathogenic  and  many 
of  the  non-pathogenic  micro-organisms  have  been  found  in  the  human 
mouth.  He  has  isolated  and  cultivated  more  than  a  hundred  different 
species  obtained  from  the  human  mouth,  thus  establishing  the  fact  that 
this  cavity  is  the  receptacle  and  often  the  breeding-ground  of  a  considera- 
ble number  of  specific  micro-organisms,  as  well  as  the  source  through 
which  infection  of  many  serious  and  sometimes  fatal  diseases  may  take 
place. 

Among  the  more  important  forms  of  pathogenic  micro-organisms  which 
he  found  in  the  mouth  may  be  mentioned  the  Micrococcus  of  sputum  septi- 
ccemia,  Bacillus  crassus  sputigenus,  Staphylococcus  aureus  and  albus,  Strepto- 
coccus pyogeneSy  Micrococcus  tetragenus,  the  Pneumococcus  of  pneumonia,  and 
many  others. 

MOUTH  BACTERIA  PROPER. 

Six  forms  of  micro-organisms  which  are  common  to  almost  every 
mouth,  and  termed  by  Miller  "Mouth  Bacteria  Proper,"  have  the  peculi- 
arity that  no  culture -medium  has  yet  been  found  upon  which  they  can  be 
grown.  Miller  has  experimented  in  hundreds  of  ways  to  cultivate  them, 
but  without  success. 

These  are  the  LeptotJirix  innominata,  Bacillus  tuccalis  maximus,  Leptothrix 
buccalis  maxima,  Jodococcus  vaginatus,  Spirillum  sjndigenum,  Spirochcete  den- 
tium  (denticola). 

The  term  Leptothrix  buccalis  was  first  used  by  Eobin,  and  has  been  ap- 
plied to  almost  every  living  organism  that  has  been  found  growing  in  the 
mouth.  Miller  thinks  it  should  be  banished  from  all  bacteriologic 
writings  on  account  of  the  confusion  which  it  creates.  He  objects,  also, 
to  the  term  Bacterium  termo,  as  it  has  so  often  been  misapplied,  some 
authors  classing  every  organism  showing  a  slight  contraction  in  the  mid- 
dle as  Bacterium  termo. 

Leptothrix  Innominata. — This  term  has  been  proposed  by  Miller  for 
those  bacteria  growing  in  threads,  whose  biology  is  too  little  known  to 
define  their  relation  to  other  mouth  bacteria,  or  to  form  a  separate  group 
with  distinct  characteristics. 


Fig.  '213.— Leptothrix  buccalis.     (V.  A.  Latham.)     X  193.75- 


*  1     '  -hSf 


Fig.  244.— Mouth  bacteria.     (R.  K.  Andrews. )     A,  diplococci ;  B,  leptothrix  buccalis. 


BACTERIOLOGY    OF    THE    MOUTH. 


93 


This  organism  is  found  in  every  mouth,  but  in  varying  quantities, 
depending  largely  upon  the  personal  habits  of  the  individual.  It  occurs 
in  the  soft  white  deposits  which  accumulate  on  the  teeth ;  sometimes  it 
appears  in  masses,  at  other  times  it  will  be  sparingly  found  (Fig.  243). 
These  masses,  according  to  Miller,  vary  in  size,  and  consist  apparently  of 
small  round  granules,  from  whose  margins  thin,  more  or  less  zigzagged 
thi-eads  project. 

These  granular  masses  form  the  so-called  ''matrix  of  Leptothrix  huc- 
ccdis,^^  and  were  formerly  looked  upon  as  its  spores,  but  are  in  reality 
partly  micrococci  and  partly  only  crossings  of  the  threads  themselves. 

The  threads  vary  considerably  in  length,  and  are  from  0.5, a  to  O.S/j. 
broad  ;  they  are  twisted,  tortuous,  immotile,  and  inarticulated,  and  take 
a  faint  yellow  stain  with  iodine.  They  often  appear  degenerated  or  even 
lifeless.  Shorter  threads  or  rods  are  also  found  which  may  be  either  frag- 
ments of  the  threads  or  young  cells  (Fig.  244). 

Bacillus  Buccalis  Maximus. — This  organism  is  the  largest  occurring 
in  the  mouth.  The  threads  measure  from  30  to  150/^  long,  the  separate 
rods  are  from  2  to  10, a  long  and  from  1  to  1.3  m  broad.  Miller  found  it  in 
isolated  threads,  but  most  often 

in  tufts,   the  threads  having  a  ^^^-  ^'^^^ 

parallel  direction,  separate  bun- 
dles sometimes  crossing  each 
other. 

The  rods  have  a  very  regu- 
lar contour,  and  are  usually  of 
the  same  thickness  throughout 
(&,  Fig.  245,  is  an  exception). 
Iodine  stains  the  majority  of 
the  threads  brown-violet,  either 
throughout  or  in  isolated  sec- 
tions. Miller  has  never  found 
them  in  the  dentinal  tubuli ;  their 
size  would  not  permit  their  en- 
trance. Its  size,  the  distinct  and 
regular  articulation  of  the  rods, 
the  absence  of  the  zigzag  windings,  and  its  reaction  to  iodine,  Miller  thinks 
should  preclude  it  from  being  classed  with  the  Lejytoihrix  innominata. 

Leptothrix  Buccalis  Maxima. — Miller  has  given  this  name  to  a  form 
of  Leptothrix  threads  which  he  found  in  the  mucous  deposits  upon  the 
teeth.  He  describes  the  organism  as  having  long,  thick,  straight  or  curved 
filaments,  which  show  a  marked  resemblance  in  form  to  the  Bacillus  huc- 
calis  maximus  just  described,  except  that  the  joints  are  somewhat  shorter 
in  the  latter.  It  does  not  give  the  iodine  reaction.  For  these  reasons  he 
does  not  feel  sure  whether  it  is  a  different  variety  or  the  immature  cells  of 
the  same  variety  in  which  the  substance  which  takes  the  blue  color  is  not 
yet  formed. 

Jodococcus  Vaginatus. — This  organism  is  found  almost  universally 
in  unclean  mouths.     Miller  has  never  failed  to  find  it  except  in  two  in- 


Bacillua  buccalis  maximus. 
solution. 


After  treatment  with  iodine 
ISOO :  1. 


94  OPERATIVE    DENTISTRY, 

stances  of  children,  aged  respectively  five  and  six  years.  He  describes  it 
as  appearing  singly  or  in  chains  of  from  four  to  ten  cells,  longer  chains 
rarely  being  seen. 

They  are  of  coccus  form ;  the  cells  appear  sometimes  as  flat  disks,  or 
rounded  or  even  square-shai3ed  bodies,  being  enclosed  in  a  sheath.  The 
chains  have  a  diameter  of  0.73  //-.  He  occasionally  found  chains  from  which 
one  or  more  cells  were  missing,  others  whose  sheaths  had  burst,  but  from 
which  the  cells  had  not  as  yet  escaped.  The  sheaths  do  not  show  the 
iodine  reaction,  but  remain  colorless,  or  after  continued  action  of  the  re- 
agent become  yellow.  The  cell  contents  always  take  the  stain,  the  shade 
varying  from  dark  blue  to  violet. 

Spirillum  Sputigenum. — This  bacterium  is  present  in  all  mouths,  but 
in  varying  quantity.  In  cleanly  mouths  the  numbers  will  be  small,  in 
those  which  are  foul  from  neglect  they  often  exist  in  prodigious  numbers. 
They  are  found  in  the  soft  deposits  at  the  margins  of  the  gums.  In  neg- 
lected mouths  with  inflammation  of  the  gums  Miller  sometimes  found  an 
almost  pure  culture  of  the  organism.  It  is  comma-shaped  in  form  and  has 
very  active  spiral  movements,  and  when  grouped  together  it  forms  short 
8j)irals  or  S-shapes,  It  is  sometimes  found  in  the  dentinal  tubules.  It  was 
for  a  time  thought  to  be  identical  with  the  comma  bacillus  of  Koch, — the 
cholera  bacillus, — but  Miller  has  proved  it  to  be  an  entirely  different 
species,  from  the  fact  that  it  cannot  be  artificially  cultivated  upon  any 
known  culture  medium,  while  the  Koch  bacillus  can  be  readily  cultivated. 
Klein,  however,  has  stated  that  the  Spirillum  sputigenum  can  be  cultivated  in 
acid  gelatin. 

Miller  discovered  and  describes  two  other  forms  of  curved  rods  or 
comma  bacilli  which  he  found  in  the  human  mouth.  The  iirst  is  not 
difficult  to  cultivate,  and  occurs  in  short,  plump,  tapering  rods,  slightly 
curved  and  generally  united  in  j)airs.  It  is  motile  and  multiplies  by 
fission. 

The  second  occurs  in  the  form  of  delicate  rods  of  varying  length,  some- 
times straight,  at  others  so  curved  as  to  form  the  arc  of  a  circle,  and  when 
joined  together  at  their  ends  forming  a  circle  or  letter  O ;  occasionally 
they  are  so  joined  as  to  form  a  letter  S.  They  are  non-motile,  and  multi- 
ply by  fission,  and  during  this  process  they  form  chains  of  cocci.  This 
organism  possesses  many  of  the  characteristics  of  the  Finkler-Prior  ba- 
cillus, but  whether  it  is  identical  has  never  been  determined. 

Spirochaete  Dentium  (deDticola). — Miller  found  this  organism  (Fig, 
246)  almost  universally  present,  not,  however,  in  decaying  dentin,  but  in 
the  same  locations  as  the  Spirillum  sputigemmi^ — namely,  at  the  margins 
of  the  gums,  in  the  deposits  found  there,  especially  when  the  gingival  bor- 
ders are  in  an  inflamed  condition.  This  organism  is  of  spiral  form,  from 
8  to  25  A  long,  of  unequal  thickness,  very  irregular  windings,  and  with 
marked  differences  in  their  susceptibility  to  staining  reagents. 

Miller  is  not  sure  whether  they  are  two  separate  organisms,  or  only 
different  stages  in  the  development  of  the  Spirillum  sputigenum. 

In  Fig.  247  it  will  be  noticed  that  the  same  spiral  or  comma-shaped 
bacilli  have  flasfellse. 


Fig.  24<).— Spirochseta  dentium  (deiiticola)  and  leptothrix  threads.     : <  1000. 


ITlG.  247. — Spirochseta  dentium    (denticola),  showing  their  fiagella.     :<  1000. 


Fig.  248.— Leptothrix  gigantea,  from  dog.  750. 


Fig.  219.— LeptothriN;  gigantea.     (V.  A.  Latham  )  1000. 


Fig.  250.— Leptothrix  gigantea.     (Miller.)         1000. 


BACTERIOLOGY    OF   THE    MOUTH.  95 

Leptothrix  Gigantea. — This  very  remarkable  organism  (Fig.  248)  was 
found  by  Miller  in  the  mouth  of  a  dog  suffering  from  pyorrhoea  alveolaris, 
and  to  which  he  has  given  the  above  name,  suggested  by  its  enormous 
dimensions.  It  grows  in  tufts  or  fascicles  whose  threads  diverge  from  a 
common  point  of  adhesion  (Fig.  249).  It  forms  cocci,  rods,  and  threads, 
and  therefore  belongs  to  that  group  of  bacteria  known  as  pleomorphic, 
having  more  than  one  form.  The  threads  of  the  individual  tufts  vary 
considerably  as  to  their  thickness  ;  some  are  very  thin,  others  very  thick. 
They  sometimes  appear  straight  (Fig.  250),  at  others  irregularly  curved 
or  twisted  into  spirals. 

He  did  not  determine  its  etiologic  relations  to  the  disease.  In  exam- 
ining the  mouths  of  other  animals — sheep,  cattle,  pigs,  horses,  dogs,  cats, 
rabbits,  etc. — he  frequently  found  leptothrix-like  fungi. 

Besides  these  micro-organisms,  there  are  a  very  great  number  of  others 
that  are  found  at  different  times  in  the  human  mouth,  many  of  which  are 
pathogenic.  Miller  has  made  the  estimate  that  in  a  certain  very  unclean 
mouth  there  were  not  less  than  1,140,000,000  of  micro-organisms. 

With  such  conditions  as  these  it  is  not  surprising  that  the  human  saliva 
is  poisonous  and  sometimes  possessing  very  virulent  toxic  properties,  which 
may  endanger  the  life  of  the  operator  who  should  be  so  unfortunate  as  to 
become  inoculated  with  it  through  some  wound  or  abrasion  upon  his 
hands. 

Biondi  isolated  from  the  human  saliva  five  different  forms  of  pathogenic 
micro-organisms,  to  which  he  gave  the  following  names  :  Bacillus  salivarius 
septicus,  Coccus  salivarius  septicns,  Micrococcus  tetragenus,  Streptococcus  septo- 
pycemicus,  and  Staphylococcus  salivarius  pyogenes.  Cultures  of  all  of  these 
organisms  were  found  to  be  more  or  less  virulent,  causing  death  in  mice 
and  guinea-pigs  in  from  twenty-four  hours  to  fifteen  days  when  injected 
subcutaneously. 

Miller  has  also  found  within  the  mouth  a  considerable  number  of  other 
bacterial  forms  possessing  pathogenic  i^roperties,  four  of  which  he  exam- 
ined in  detail  and  named  as  follows  :  Micrococcus  gingivce  pyogenes,  Bacte- 
rium gingivce  pyogenes,  Bacillus  dentalis  viridans,  and  Bacillus  pulpce  pyo- 
genes. 

The  first  and  second  were  found  in  the  pus  from  pyorrhoea  alveolaris  ; 
the  third  was  found  in  decaying  dentin,  and  the  last  in  gangrenous  pulps. 

Cultures  made  from  the  first  two  and  the  last  were  found  to  be  ex- 
tremely virulent,  causing  death,  when  injected  into  the  abdominal  cavity 
of  white  mice,  in  from  ten  to  twenty-five  hours. 

The  Bacillus  dentalis  viridans  was  not  quite  so  virulent  as  cultures  from 
this  organism.  When  injected  into  the  abdominal  cavity  of  mice  and 
guinea-pigs  it  produced  death  from  peritonitis  in  from  twenty-two  hours 
to  six  days. 

Black,  in  his  investigations  of  the  mouth  bacteria,  found  that  the  pyo- 
genic or  pus-producing  organisms  were  almost  constant  in  this  location, 
and  says,  "  We  must  take  into  consideration  the  fact  that  the  pyogenic  bac- 
teria are  generally  present  in  the  oral  cavity,  and  endanger  every  wound 
we  make  in  it." 


96  OPERATIVE    DENTISTRY. 

Miller,  in  giving  emphasis  to  the  fact  that  the  mouth,  loaded  as  it  is 
with  so  many  forms  of  jpathogenic  micro-organisms,  is  a  prolific  source  of 
infection,  says,  "The  diseases  caused  by  the  pathogenic  bacteria  of  the 
mouth  may  be  considered  under  six  heads,  according  to  the  point  of  en- 
trance of  the  infection  : 

"1.  Infections  caused  by  a  breach  in  the  continuity  of  the  mucous 
membrane,  brought  about  by  mechanical  injuries  (wounds,  extractions, 
etc.).     These  lead  either  to  local  or  general  disturbances. 

"2.  Infections  through  the  medium  of  gangrenous  tooth-pulps.  These 
usually  lead  to  the  formation  of  abscesses  at  the  point  of  infection  (absces- 
sus  apicalis),  but  also  sometimes  to  secondary  septicaemia  and  pyaemia, 
with  fatal  terminations. 

"3.  Disturbances  conditioned  by  the  resorption  of  poisonous  waste 
products  formed  by  bacteria. 

"4.  Pulmonary  disease  caused  by  the  inspiration  of  particles  of  mucus, 
small  pieces  of  salivary  calculus,  etc.,  containing  bacteria. 

"5.  Excessive  fermentative  processes  and  other  complaints  of  the  di- 
gestive tract,  caused  by  the  continued  swallowing  of  microbes  and  their 
poisonous  products. 

"6.  Infections  of  the  intact  soft  tissues  of  the  oral  and  pharyngeal 
cavities,  whose  power  of  resistance  has  been  impaired  by  debilitating  dis- 
eases, mechanical  irritants,  etc." 

Dr.  Filandro  Vicentini,  in  a  series  of  articles  published  in  the  Inter- 
national Journal  of  Microscopy  and  Natiiral  Science  (1894-1895),  upon  the 
"Bacteria  of  the  Sputa" and  the  Cryptogamic  Flora  of  the  Mouth,''  an- 
nounces the  discovery  of  a  thread-like  organism  or  Leptothrix,  which  he 
terms  Leptothrix  racemosa.  This  organism  he  first  found  in  the  sputa  of 
13ertussis,  and  afterwards  traced  to  the  mouth  as  its  natural  habitat,  and 
which  could  always  be  found  in  the  patina  dentaria, — plaques  of  deposit, — 
located  in  the  interdental  spaces,  if  the  material  were  gathered  in  the 
morning  before  the  fast  was  broken,  or  some  hours  after  a  meal.  This 
organism  differed  from  the  various  forms  of  Leptothrix  which  had  been 
recognized  and  described,  in  that  the  stems  or  filaments  present  a  beaded 
appearance,  and  that  these  stems  terminated  in  enlargements  or  heads 
which  contained  six  or  more  rows  of  spores,  as  shown  in  Plate  VI., 
Fig.  24. 

This  micro-organism,  he  claims,  passes  through  four  jyliases  of  develop- 
ment and  is  therefore  pleomorphic.  The  first  phase  being  common  to  all  the 
other  species  of  bacteria,  but  which  does  not,  however,  represent  its  whole 
cycle  of  life,  but  only  its  primordial  stage  of  immersed  vegetation,  or  a  vege- 
tation destined  to  propagate  in  a  liquid  or  semi-solid  media. 

In  the  second  phase  of  the  life  history  of  the  organism  many  degrees 
of  transition  may  be  observed.  These  are  represented  ' '  by  chains,  bun- 
dles, and  masses  of  intertwined  filaments,  isolated  filaments,  large  dumb- 
bell bacteria  of  the  type  p,  p,  and  y,  Plate  V.,  and  masses  of  diplococci ; 
the  large  dumb-bell  bacteria  being  derived  from  the  diplococci,  the  two 
original  cocci  linking  together.  The  chains  are  often  surrounded  by 
masses  of  diplococci,  while  in  the  same  chain  small  diplococci  may  alter- 


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PLATE  VI. 


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Q[tprr.Yiarc[ilini.deL 


BACTERIOLOGY   OF    THE    MOUTH.  97 

nate  with  elliptical  bacteria  and  medium-sized  dumb-bells,  all  perfectly 
equal,  which  form  the  largest  number." 

The  third  phase  is  generally  met  with  in  the  salivary  calculus  of  the 
teeth.  Its  predominant  elements  are  large  filaments,  often  long,  bent, 
and  reunited  in  bundles,  and  stumps.  Two  notable  features  are  observed 
in  the  large  filaments,  which  have  not  been  described  by  any  previous 
author.  The  first  of  these  is  the  division  of  the  radial  extremity  of  the 
filament  into  two  or  three  branches  (Plate  VI.,  Fig.  9).  "  In  a  the  filament 
is  broken  towards  the  top  and  exhibits  two  long  roots  ;  in  h  there  are  three 
hood-shaj)ed  roots,  both  appearing  to  be  swollen  at  their  ends  (c)  like 
haustoria.^''  The  author  raises  the  query  of  the  use  of  these  barbs  or  roots, 
if  they  are  not  to  obtain  a  firm  foundation  in  the  soil.  And  to  what 
purpose  a  firm  foundation,  if  not  to  support  higher  forms  of  vegetation  ? 

The  second  feature  is  that  of  the  enlargement  or  ''swelling  of  the  ter- 
minal ends  of  the  filaments,  as  shown  in  &  and  c,  Fig.  9,  and  these  are  of 
varied  form,  at  times  containing  a  kind  of  nucleus.  Plate  VI.,  Fig.  26,  a 
and  &,  show  further  development  into  heads  or  ears.  There  are  other  en- 
largements found  along  the  filament,  which  might  be  styled  knotty. 

"Intermixed  with  the  other  element — the  stumps — are  almost  all  the 
forms  of  bacteria,  bacilli,  spirilla,  etc.,  besides  a  large  number  of  very 
varied  small  chains,  after  the  types  shown  in  Plate  V.,  c,  d,  Jc,  i,  x, 
and  a/." 

The  large  size  of  the  stumps  he  thinks  may  be  accounted  for  by  the 
fact  that  "the  points  of  the  filaments  are  removed  by  friction  or  other 
mechanical  means,  and  this  seems  to  impart  a  greater  develoj)ment  to  the 
remaining  stems  in  the  sense  of  greater  thickness,  as  happens  in  the 
pruning  of  trees,  through  the  retrocession  of  the  ascending  sap."  This 
he  thinks  explains  "the  appearances  of  the  stumps  and  their  fragments, 
which  are  so  various,  and  which  led  Miller  to  make  of  residual  filaments 
two  distinct  species, — viz.,  Leptothrix  huccalis  maxima  and  Bacillus  hiccalis 
maximus,  while  the  fertile  filaments  which  he  had  discovered  constitute 
Miller's  third  species,  the  Leptothrix  innominata.^^ 

"From  the  tiny  islands  of  the  stumps  ia  question  spring  at  last  the 
fructifications.  The  larger  filaments  gradually  become  thinner  and  pale, 
showing  in  their  interior  countless  granules  or  parietal  gemmules.  These 
are  the  fertile  filaments.  They  may  spring  either  from  the  proper  fila- 
ments with  continuous  contour  or  from  the  little  chains,  d,  Plate  VI.,  Fig. 
9,  which  are  seen  occasionally  on  the  top  of  those  filaments ;  and  in  this 
last  case,  instead  of  a  gradual  thinning,  may  abruptly  pass  from  the 
chain  to  the  fertile  filament,"  as  shown  in  the  figure.  This  phase  the 
author  terms  incomplete  aericd  vegetation. 

The,  fourth  phase  he  ievm^  complete  aerial  vegetation  or  fructification.  In 
this  stage  the  fructification  heads  or  ears  have  reached  a  developmental 
stage,  which  shows  the  formation  of  spores  arranged  in  three  rows  (Plate 
VI.,  Figs.  10  and  13). 

' '  The  fertile  filaments  are  sometimes  straight,  at  others  bent  or  curved  ; 
occasionally  they  are  entirely  wanting,  because  the  fructifications  have 
been  carried  away  by  mechanical  force." 

7 


98  OPERATIVE    DENTISTRY. 

In  Plate  VI.,  Fig.  10,  at  a,  a,  ''gemmules  of  reserve"  are  seen  adhering 
to  the  walls  of  the  stem  ;  at  h  the  little  spores  are  properly  lodged  ;  at  h'  only- 
five  are  seen,  the  others  having  dropj^ed  ;  at  c  the  penultimate  articula- 
tions of  the  stalk  appear  older  and  woody  ;  the  last  is  granular,  like  the  two 
articulations  on  the  apex  of  the  younger  filament,  d. 

The  sporules,  which  are  very  small  and  round,  are  arranged  in  three 
vertical  rows  ;  this  is  the  appearance,  almost  without  exceiDtion,  in  all  the 
specimens  observed,  hence  it  is  inferred  by  Yicentini  that  they  are  ar- 
ranged in  six  longitudinal  lines.  In  several  specimens  stained  with  picric 
acid  the  iDrolongations  of  the  stem  into  the  interior  of  the  fructification 
head  could  be  distinctly  traced.  Staining  with  aniline  colors  rendered 
the  viscid  substance  in  which  the  sporules  are  suspended  opaque  ;  but  if 
glycerol  was  substituted  for  water  in  the  preparation  of  the  slide,  the 
stalk  after  a  long  time  reappears  distinctly  in  all  its  length.  The  stalk 
and  the  ear  form  a  continuous  whole,  and  he  likens  a  tuft  of  the  organism 
with  its  vibrating  ears  to  ''  a  field  of  wheat." 

The  length  of  the  ears  is  frequently  considerable,  as  shown  in  Plate  YI., 
Fig.  16,  the  more  conspicuous  specimens  being  found  in  pulmonary  sputum, 
' '  the  largest  being  one-sixth  of  a  millimetre. ' ' 

Bacteria  in  general  are  reproduced  by  two  methods, — viz.,  hj  fission  or 
cell  divisions,  and  by  the  formation  of  spores  within  the  parent  cell, 
termed  endogenous  spore  formation.  Another  method  of  reproduction  is 
known  as  arthrosporous  reproduction.  By  this  process  spores  are  formed 
out  of  portions  of  the  cell-body,  or  some  of  the  individual  cells  of  the 
latter  set  free  from  the  parent  organism,  the  opposite  of  endogenous  spore 
formation.     Yery  little  is  known  of  this  process  at  the  present  time. 

Still  another  method  of  reproduction  may  be  mentioned  :  this  is  termed 
acrogenous  abjunction,  a  process  by  which  spores  are  formed  at  the  apices 
of  certain  cryptograms.  In  this  process  the  terminal  cell  becomes  en- 
larged and  transformed  into  what  is  known  as  a  hasidium, — a  diminutive 
base, — from  which  external  sprouts  or  sterigmata,  bearing  spores  or  sperma- 
tia  upon  their  terminal  ends,  arise. 

Yicentini  believes  from  his  study  of  the  Leptothrix  raoemosa  that  it 
propagates  by  two  distinct  methods,  the  first  by  " internal  gemmulation,^^ — 
endogenous  spore  formation, — which  he  terms  the  "inferior  or  first  cycle," 
and  the  other  by  " conjugated  fructification,^^ — acrogenous  abjunction, — 
which  he  terms  the  "superior  cj^cle."  He  claims  that  "the  organism 
possesses  real  organs  of  reproduction  by  which  it  would  resemble  fungi  and 
dioecious  algce,  with  distinct  sexes  upon  different  filaments  or  individuals. 

Its  fertile  filaments  are  at  times  engrafted,  with  two  or  three  roots,  upon 
clods  or  firm  substrata,  and  end  in  fructification.  The  ears  are  linked 
together  and  fastened  to  a  stalk,  as  shown  in  Plate  YI.,  Fig.  16.  Other  fila- 
ments, however,  less  numerous  than  these,  at  times  multiply,  and  lastly, 
branching  off,  bear  certain  j)roductions  by  points,  the  male  elements  (Plate 
YI.,  Fig.  14)  or  pseudo-inflorescences  or  blossoms  formed  of  spindle-like 
{d,  Fig.  14),  snake-like,  or  comma  bacilli  {Spirillum  sputigenum),  destined 
from  all  appearance,  through  their  lively  activity,  to  the  function  of  con- 
jugation. 


BACTERIOLOGY    OF    THE    MOUTH.  99 

This  investigator  was  able  to  observe  the  complete  process  of  fructifi- 
cation of  the  organism  in  sputa  impregnated  with  its  elements.  The 
process  is  completed  upon  the  fourth  day  by  keeping  it  well  sheltered  in 
the  dark. 

Yicentini  makes  the  bold  statement  that  he  believes,  from  a  study  of  the 
various  phases  through,  which  the  LeptotJirix  racemosa  passes  in  its  life  his- 
tory, that  it  is  with  perhaps  one  excejDtion  the  mother  organism  of  all  the 
bacteria  and  bacilli  found  in  the  sputum.  He  says,  "Of  the  six  primary 
species  of  fungi  of  the  mouth,  described  by  Miller,  there  would,  in  fact, 
exist  only  one,  the  Leptotlirix  huccalis  of  Eobin  (Leptothrix  innominata  of 
Miller),  or  at  most  a  second  one,  the  Si^irillum  (Spiroclicete  dentium  of 
Miller).  The  other  four  types  would  represent,  if  we  are  not  mistaken, 
only  phases,  or  disintegrated  i)articles  of  the  microphyte, — viz.,  Bacillus 
buccalis  'maximus  and  Leptotlirix  huccalis  maxima,  fragments  of  the  stumps 
that  form  the  inferior  layer  of  vegetation  :  the  Jodococcus  vaginatus  series 
of  special  sheaths  of  bacteria  proceeding  from  certain  'gemmules  of  re- 
serve, '  enclosed  in  the  filaments  ;  the  Spirillum  sputigenum  (comma  bacilli) 
with  our  spindle-like  and  serpentine  appendages  detached  from  the  pseudo- 
inflorescences  (blossoms),  and  probably  male  organs. 

"All  these  particles  or  articulations  cut  from  the  mother  plant  (except 
the  last, — viz.,  the  copulative  filaments)  multii^ly  by  themselves,  in  va- 
rious ways,  according  to  the  condition  of  the  nutrient  substratum,  in  the 
liquid  menstrua  or  on  firm  soil." 

He  further  suggests,  as  have  some  other  investigators,  that  the  patho- 
genic or  virulent  properties  of  bacteria  are  in  all  probability  acquired  as  a 
result  of  their  environment,  and  that  it  is  not  necessarily  a  permanent 
quality. 

This  may  exj^lain  the  periods  of  activity  and  of  immunity  which  are 
observed  in  relation  to  the  progress  of  dental  caries. 

Dr.  J.  Leon  Williams,  in  an  article  in  the  Dental  Cosmos  (April,  1899) 
upon  the  "Bacteriology  of  the  Human  Mouth,"  states  that  he,  without 
knowing  of  the  discovery  of  Yicentini,  had  some  two  or  three  years  later 
made  an  identical  discovery  of  the  fructification  of  Lei^tothrix  threads.  He 
says,  "While  studying  mouth  bacteria  I  came  across  very  regular  arrange- 
ments of  coccus  forms  about  the  ends  of  Leptothrix  threads.  At  first  I  re- 
garded these  as  purely  accidental.  But  the  persistence  and  regularity 
of  these  forms  in  nearly  every  one  of  the  preparations  I  was  then  making 
led  me  to  examine  them  more  closely,  and  I  was  astonished  to  find  what 
appeared  to  be  a  thorn-like  connection  between  the  spore  or  coccus  form 
and  the  leptothrix-like  thread." 

After  reading  the  work  of  Yicentini,  which  was  brought  to  his  atten- 
tion by  a  friend  to  whom  he  had  mentioned  his  own  discovery,  Williams 
went  forward  with  his  work.  His  method  of  j)rocedure  is  as  follows  :  "  A 
stream  of  sterilized  water  is  thrown  from  a  iDOwerful  syringe  into  the  inter- 
dental space  between  the  first  and  second  upper  molars.  With  a  sharp, 
sickle-shaped  instrument,  previously  sterilized,  a  gelatinous  microbic 
plaque  is  removed,  which  appears  upon  the  instrument  as  small,  grayish- 
white  material,  which  possesses  considerable   tenacity.      This  is  placed 


100  OPERATIVE    DENTISTRY. 

upon  a  clean  watch-glass  and  covered  with  twenty  or  thirty  drops  of  a 
thin,  watery  solution  of  methyl  violet  aniline,  the  mass  being  allowed  to 
remain  in  the  solution  for  twelve  hours,  but  in  the  mean  time  occasionally 
teasing  it  apart  to  obtain  a  better  penetration  of  the  staining  fluid.  The 
fluid  is  then  drained  off  and  the  mass  washed  first  with  sterilized  water 
and  then  with  a  mixture  of  equal  parts  of  glycerol,  spirit,  and  water.  A 
drop  of  the  same  mixture  is  then  placed  upon  a  cover-glass,  the  stained 
mass  dropped  into  it,  and  teased  apart  as  much  as  possible,  and  then  care- 
fully inverted  on  a  slide,  care  being  taken  to  make  as  little  pressure  as 
possible  upon  the  cover-glass.  The  preparation  will  now  show  fields  sim- 
ilar to  Figs.  251  and  252  if  examined  with  a  one-sixth-inch  objective. 
Under  a  one-tenth-  or  one-twelfth-inch  objective  in  fortunate  specimens, 
fields  like  Fig.  253  will  be  observed.  Such  a  view  very  clearly  resembles 
a  grass-plot,  from  which  arise  the  blossom,  fruit,  or  seed-heads  of  the  plant. 
These  are  the  fruit  or  spore-heads  of  a  thread-like  micro-organism,  which 
I  have  found  to  be  as  constant  as  any  form  of  bacteria  in  the  human 
mouth."  The  Leptothrix  racemosa  of  Yicentini  (Fig.  254)  shows  such  a 
field  under  high  magnification. 

This  organism  Yicentini  describes  as  having  ears  or  fruit-heads  made 
up  of  six  regularly  arranged  rows  of  spores  or  seeds.  Williams  has  se- 
cured a  few  lucky  views  of  the  heads  in  cross-section,  which  show  them  to 
be  composed  of  twelve  rows  or  even  more. 

The  attachment  of  the  spores  to  the  central  stalk  by  the  thorn-like 
processes,  sterigmata,  or  peduncles,  and  which  constitutes  the  final  and 
irrefutable  proof  of  the  correctness  of  Yicentini' s  claim  of  the  fructifica- 
tion of  the  Leptothrix  racemosa,  is  most  beautifully  shown  in  Figs.  255  and 
256,  while  in  Fig.  257  the  spore  attachment  in  both  longitudinal  and  trans- 
verse section  is  likewise  finely  shown.  Fig.  258  shows  a  transverse  section 
under  a  magnification  of  about  nine  thousand  diameters. 

Williams  believes  with  Yicentini  that  the  organism  is  one  of  very  rapid 
growth  and  common  to  all  mouths,  and  the  forms  which  must  result  from 
the  breaking  up  of  the  spore  heads  and  stem  of  the  organism  are  Jong  and 
short  rods^  various  sizes  of  micrococci,  various  sizes  of  diplococci,  and  various 
sizes  of  curved  and  clvh-shaped  hacillL  He  further  says,  ^ '  I  have  no  dispo- 
sition to  indulge  in  speculation  over  these  discoveries,  but  here  are  the 
facts  which  must  be  reckoned  with  in  all  future  considerations  of  the  bac- 
teria of  the  human  mouth  and  body.  It  would  be  folly  to  deny  that  these 
facts  are  big  with  possibilities.  .  .  .  However  much  we  may  be  disposed 
to  reticence,  it  is  imi)ossible  to  avoid  asking  what  becomes  of  the  enormous 
number  of  micro-organisms  of  different  forms  and  sizes  which  are  being 
constantly  shed  into  the  human  mouth  by  this  parent  organism,  and  how 
many  of  them  have  been  classified  as  x^ermanent  si)ecies." 

TJj)on  this  j)oint  Yicentini  says,  "  According  to  my  calculations  not 
less  than  from  two  to  three  hundred  trillions  of  germs  or  separated  ele- 
ments are  generally  present  in  the  mouth  and  nose,  liable  to  disseminate 
the  species  at  every  minute  into  other  parts." 

There  is  a  question,  however,  whether  these  organisms  are  not  placed 
in  the  mouth  by  nature  for  a  beneficent  purpose.     Fabulous  numbers  of 


Fig.  'iol. — The  material  from  which  this  photograpli  was  made,  and  all  of  those  which  follow,  was 
obtaiued  by  scraping  the  approximal  surfaces  of  teeth  after  thoroughly  syringing  with  sterilized  water, 
and,  in  some  instances,  also  after  rubbing  the  surface  of  the  tooth  with  a  wad  of  sterilized  cotton-wool. 
The  gelatinous  mass  of  micro-organisms  adheres  to  the  surface  of  the  enamel  with  considerable  tenacity. 
The  scrapings  were  stained  with  watery  solution  of  gcntian-violet-anilin  water  and  mounted  m  diluted 
glycerol.  Under  a  power  of  four  cr  five  hundred  diameters  places  will  be  found  presenting  such 
appearances  as  are  shown  above.     (T.  Leon  'Williams.) 


Fig.  252.— Frnctification  heads  of  hptothrix  racanosa.     Zeiss  objective  :',  mm.,  ])rojection  ocular  3. 

(J.  Leon  Williams.) 


Fig.  2b'i. — Fructification  heads  of  leptothrix  racemosa.     (J.  Leon  Williams.) 


Fig.  254.— Thick  growth  of  leptothrix  racemosa  fructification  heads  from  approxinial  surface  of  tooth,  under 
high  magnifying  power.     (J.  Leon  Williams.) 


Fig.  i.Vi.— Fructitication  beads  of  Uploihrix  raccmosn. 


Fig.  2n6. — Fructification  heaiis  of  Irptntlnix  rncemosd. 


Fig.  257. — Showing  attachment  of  spores  to  central  stem  in  both  longitudinal  and  transverse  section. 

(J.  Leon  Williams.) 


Fig.  258. — This  photograph  is  from  au  enlarged  negative  made  from  an  original  photograph  of  trans- 
verse section  of  fructification  head  of  leptothrix  racanosa.  The  original  negative  was  magnified  to  2000 
diameters.  The  enlarged  negative  and  the  above  print  represent  an  amplification  of  about  9000 
diameters.  It  shows  the  cell  wall  and  the  shrinkage  of  the  protoplasm  caused  by  the  action  of  the 
glycerol  and  spirit.  The  spore-stems,  or  sterigmata,  are  seen  to  arise  from  the  central  protoplasm  and  to 
pass  through  the  cell  wall.     (J.  Leon  Williams.) 


BACTERIOLOGY    OF    THE    MOUTH.  101 

them  are  constantly  passing  into  the  digestive  tract,  where  they  may,  as 
suggested  by  Hallier,  take  an  active  part  in  the  transformation  of  the  in- 
gested food  by  the  transmutation  of  the  starchy  elements  into  glucose, 
both  in  the  mouth  and  the  stomach.  Miller  and  others  have  recognized  in 
the  buccal  bacteria  a  peptonizing  action  equal  to  pepsin  itself,  even  with- 
out the  action  of  acids. 


BACTERIA   WHICH   AFFECT  THE    INTEGRITY   OF   THE   DENTAL   TISSUES. 

The  zymogenic  and  the  saprogenic  micro-organisms  have  also  a  distinct 
interest  for  the  dental  surgeon  from  the  fact  that  certain  species  of  the  zy- 
mogenic bacteria  have  for  their  special  function  the  formation  of  acids 
within  the  mouth  by  the  fermentation  of  the  carbohydrates  which  are 
lodged  there  as  alimentary  debris,  and  also  that  certain  other  species  of 
the  saprogenic  bacteria  have  the  power  of  liquefying  albuminoid  sub- 
stances or  digesting  them  by  the  production  of  a  soluble  ferment. 

According  to  the  now  generally  accepted  theory  of  dental  caries,  these 
micro-opganisms  are  the  j)rime  factors  in  the  production  of  this  disease. 

The  fermentation  of  the  carbohydrates  within  the  mouth  is  produced 
by  certain  species  of  bacteria,  the  results  of  which  are  the  formation  of 
various  compounds,  lactic  acid,  mannite,  dextrin,  etc.  According  to 
Miller,  butyric  acid  is  never  found  in  the  mouth  except  as  a  by-product  in 
lactic  acid  fermentation. 

The  fermentation  of  the  carbohydrates  is  chiefly  productive  of  the 
formation  of  lactic  acid  ;  this  is  brought  about  by  certain  species  of  bac- 
teria acting  upon  these  fermentable  compounds  and  converting  them  into 
lactose  and  lactic  acid,  with  or  without  the  evolution  of  carbon  dioxide. 
(Miller.) 

A  considerable  number  of  micro-organisms  are  capable  of  affecting 
this  transformation. 

Miller,  experimenting  with  twenty  different  species  of  mouth  bacteria 
upon  the  carbohydrates,  obtained  in  sixteen  of  them  an  acid  resultant, 
while  in  one  of  the  others,  which  was  found  in  a  putrid  pulp,  the  evolu- 
tion of  gas  was  so  copious  as  to  tear  the  gelatin  into  shreds. 

Vignal  found,  in  his  researches  upon  the  mouth  bacteria,  that  out  of 
seventeen  different  varieties,  seven  of  them  liquefied  coagulated  albu- 
min, five  others  caused  it  to  swell  and  become  transparent,  ten  dissolved 
fibrin,  nine  dissolved  gelatin,  seven  coagulated  milk,  six  dissolved  casein, 
three  transformed  starch,  and  nine  converted  lactose  into  lactic  acid  ;  the 
majority,  it  will  be  seen,  had  a  i)eptonizing  effect,  and  some  of  them  grew 
indei^endent  of  free  oxygen. 

The  jprincipal  organism,  however,  in  the  production  of  lactic  acid,  and 
one  which  is  constantly  found  in  the  human  mouth,  is  the  Bacterium  acidi 
lactici  of  Huepj)e. 

Among  the  carbohydrates  which  are  most  highly  fermentable  and 
readily  acted  upon  by  the  lactic  acid  bacterium  are  the  sugars,  dextrin, 
starch,  cellulose,  etc.,  and  these  are  always  found  in  the  mouth,  in  greater  or 
less  quantities,  as  alimentary  debris^  ready  to  be  acted  upon  by  zymogenic 


102  OPEEATIVE    DENTISTRY. 

bacteria.  The  mouth  presents  at  all  times  the  necessary  degree  of  heat 
and  of  moisture  for  the  rapid  growth  of  these  organisms.  Lactic  acid 
in  very  dilute  solutions  readily  acts  upon  the  inorganic  substances  of 
enamel  structure  and  disintegrates  it,  and  thus  opens  the  way  for  caries 
to  attack  the  dentin.  The  organisms  which  i)roduce  lactic  acid  enter  the 
dentinal  tubuli,  where  they  continue  to  generate  acid,  which  removes  the 
calcium  salts,  while  the  liquefying  or  peptonizing  action  of  other  forms  of 
bacteria  dissolve  the  decalcified  dentin  matrix. 

Several  other  fermentations  of  carbohydrates  take  place  within  the 
mouth,  by  which  mannite,  dextrin,  etc.,  are  formed. 

Mannite  is  the  product  of  a  fermentation  induced  by  an  exceedingly 
small  coccus — Micrococcus  viscosus — which  grows  in  chains  in  various  sac- 
charine beverages,  in  wine,  beer,  etc.,  and  in  saccharine  juices  (Miller), 
and  forms  a  gummy  product  known  as  mannite.  Black  believes  that  this 
substance  is  the  cause  of  sordes  which  accumulate  upon  the  teeth  in  the 
continued  fevers,  and  that  it  may  be  the  cause  of  thick,  ropy  saliva. 

Dextrin  is  formed  as  the  result  of  fermentation  caused  by  the  action 
of  a  micrococcus — Leuconostoc  mesenterioides — upon  beet-juice  and  molasses, 
and  can  be  induced  artificially  in  saccharine  solutions.     (Miller.) 

Action  of  Pathogenic  Bacteria. — The  question  of  how  the  xmthogenic 
hacteria  i^roduce  their  effects  u])on  the  living  tissues  of  the  body  is  one  ux)on 
which  there  is  still  a  wide  difference  of  belief.  Some  observers  are  of  the 
opinion  that  the  symptoms  of  infectious  diseases  are  the  result  of  the  for- 
mation by  the  micro-organisms  of  chemical  substances  of  an  irritating  or 
poisonous  nature,  a  sort  of  si^ecific  excretia. 

Others  believe  the  phenomena,  both  local  and  constitutional,  to  be  due 
to  changes  wrought  within  the  tissues  by  the  organisms  themselves  during 
their  develoi^ment,  and  that  it  is  not  necessary  to  assume  the  formation  of 
a  specific  x^oison  or  virus  to  account  for  these  phenomena. 

The  action  of  the  pyogenic  or  pus-producing  bacteria  is  to  produce 
local  irritation  or  inflammation,  while  the  chemical  substances  elaborated 
in  the  focus  of  infection  are  disseminated  throughout  the  body,  which,  by 
virtue  ot  a  i:)eculiar  action,  thought  to  be  ferment-like,  augments  tissue 
metamorphosis,  stimulates  the  "thermic  centres"  and  thereby  increases 
the  body  temperature,  producing  fever  or  systemic  disturbance.  This 
condition  is  known  as  septic  infection. 

The  absorption  of  ptomaines  without  the  presence  of  pathogenic  bacte- 
ria will  produce  grave  systemic  disturbances.  This  condition  is  termed 
septic  intoxication,  or  toxic  infection. 

Ftomaines  are  powerful  animal  poisons  developed  by  the  process  of  de- 
composition of  animal  tissue  in  the  presence  of  saprophytic  bacteria.  In 
their  physiologic  action  they  resemble  the  alkaloids,  and  when  received 
into  the  circulation  by  the  process  of  absorption  they  produce  more  or  less 
severe  constitutional  symptoms.  The  '  ^  toxines' '  probably  belong  to  this 
class  of  substances. 

The  develoi^ment  of  the  ptomaines  seems  to  exert  a  controlling  or  in- 
hibitory effect  upon  the  growth  of  the  micro-organisms.  Many  of  the 
artificial  cultures  of  bacteria,  after  a  period  of  growth,  cease  to  develop, 


BACTERIOLOGY  OF  THE  MOUTH.  103 

and  it  is  partly  by  virtue  of  the  formation  of  these  substances  that  this 
controlling  effect  is  brought  about. 

Leucomaines  are  animal  alkaloids  which  are  produced  within  the  living 
tissues  by  metabolism — tissue  changes — independent  of  micro-organisms. 
The  pathologic  significance  of  these  products  is  as  yet  not  well  defined. 

Immuniiy. — The  effects  of  the  virus  of  certain  bacteria  upon  the  vital 
fluids  and  the  tissues  of  the  body  in  certain  diseases  is  to  give  protection 
against  future  attacks  ;  in  other  words,  to  render  the  organism  immune. 

Pasteur  believed  this  protection  or  immunity  to  be  due  to  the  ex- 
haustion of  the  chemical  substances  supi^osedly  necessary  to  maintain  the 
life  and  development  of  the  siDCcific  bacteria. 

Fraenckel  was  of  the  opinion  that  the  first  invasion  of  the  bacteria  left 
behind  certain  substances  which  were  inimical  to  the  further  development 
of  the  same  species  of  micro-organisms,  which  might  at  some  other  time 
gain  an  entrance  to  the  system. 

From  the  foregoing  pages  it  will  be  readily  appreciated  that  the  diffi- 
culties to  be  surmounted  in  securing  an  aseptic  condition  of  the  mouth  are 
so  great  as  to  make  it  an  imj)ossibility. 

Much  can  be  attained,  however,  by  a  scrupulous  attention  to  certain 
hygienic  rules, — viz.,  brushing  the  teeth  after  each  meal,  followed  by  the 
use  of  floss-silk  passed  between  the  approximating  surfaces,  and  the  assid- 
uous use  of  antiseptic  mouth-washes. 

Boric  acid  in  fifty  per  cent,  solution,  cinnamon  water,  formal  (one  per 
cent.),  listerine,  pasteurine,  and  borolyj)tol  are  all  valuable  antiseptics  for 
this  purpose. 

Too  much  care  cannot  be  exercised  by  the  dentist  and  the  surgeon  in 
thoroughly  cleansing  the  mouth  and  the  teeth  before  commencing  any 
operation  which  involves  a  breaking  of  the  continuity  of  the  soft  tissues. 
and  the  thorough  sterilization  of  all  instruments  and  dressings  used  in  the 
operation.  A  no  less  important  precaution  is  that  of  thoroughly  cleansing 
the  hands  and  finger-nails  of  the  oj)erator,  and  washing  them  in  antiseptic 
solutions.  Failure  to  do  this  often  results  in  the  introduction  of  pyogenic 
bacteria  and  establishing  suppurative  processes,  which  with  proper  care 
might  have  been  avoided. 

STERILIZATION   OF   HANDS   AND   INSTRUMENTS. 

Absolute  cleanliness  in  all  operations  within  the  mouth  is  of  such  great 
importance  from  the  surgical  stand-point  that  too  much  stress  cannot  be 
laid  upon  its  strict  observance  in  every  detail.  This  comprehends  the  steril- 
ization of  the  hands  of  the  operator,  of  the  mouth  and  teeth  of  the  patient, 
of  the  instruments  used  in  the  operation,  of  the  rubber  dam,  and  of  other 
materials  employed  for  the  exclusion  of  moisture. 

The  student  who  would  be  successful  in  the  treatment  of  the  diseases 
and  injuries  to  which  the  teeth  and  the  mouth  are  subject  must  be  taught 
to  appreciate  the  value  of  antisepsis  and  the  technique  of  its  employment. 

Carelessness  upon  the  part  of  the  operator  in  not  observing  the  ordi- 
nary precautions  of  aseptic  methods  may  not  always  result  in  sprea'ding 
infection  ;  but  this  is  due  to  the  resistance  of  the  tissues  which  have  been 


104  OPERATIVE    DENTISTRY. 

thus  endaugered,  rather  than  to  a  lack  of  transmitting  infectious  material. 
Cases  are  on  record  in  considerable  numbers  in  which  serious  consequences 
have  followed  the  employment  of  unclean  or  septic  instruments  in  opera- 
tions like  lancing  an  alveolar  abscess,  extracting  a  tooth,  etc.,  some  of 
which  have  resulted  fatally. 

Among  the  most  common  infectious  diseases  which  may  be  transmitted 
from  one  patient  to  another  by  the  hands  of  the  dentist  and  of  his  instru- 
ments are  tonsillitis,  dij^htheria,  suppurative  inflammation,  certain  forms 
of  stomatitis,  malignant  oedema,  tuberculosis,  and  syphilis.  In  view  of 
these  facts,  the  operator  should  exercise  the  greatest  circumspection  in  the 
cleansing  and  sterilizing  of  his  hands  and  instruments  when  passing  from 
one  i^atient  to  another.  The  operator  should  never  under  any  circum- 
stances x^ermit  himself  to  come  in  contact  with  his  patient  without  first 
washing  his  hands,  and  this  should  be  done  in  the  presence  of  the  patient, 
that  there  may  be  no  lingering  doubt  about  the  question  of  cleanliness ; 
while  the  instruments  which  he  is  about  to  use  should  be  taken  fresh  from 
the  instrument- case,  where  they  have  been  placed  after  being  sterilized. 
Instruments  should  never  be  permitted  to  remain  upon  the  operating-table 
after  the  patient  has  been  dismissed,  but  should  be  immediately  cleared 
away  and  placed  in  the  sterilizing  api)aratus  before  the  next  patient  takes 
the  chair.  Such  attention  to  the  appearances  of  cleanliness  is  very  gratify- 
ing to  the  scruples  of  patients,  and  increases  their  confidence  in  their 
dental  adviser  that  no  effort  will  be  lacking  upon  his  part  to  insure  them 
against  the  spread  of  disease  by  infection. 


TECHNIQUE   OF   STERILIZATION. 

Sterilization  of  the  Hands  of  the  Operator. — This  may  be  accom- 
plished by  thorough  washing  and  scrubbing  with  hot  water  and  antiseptic 
soap  ;  green  soaj)  containing  two  per  cent,  of  carbolic  acid  is  the  best  for 
this  purpose.  The  finger-nails  should  then  be  carefully  cleansed  and  the 
hands  again  washed  in  hot  water.  In  cases  of  operation  in  which  the  soft 
tissues  are  to  be  involved  the  hands  should  receive  a  bath  in  a  five  per  cent, 
solution  of  carbolic  acid,  or  a  1  to  1000  solution  of  mercuric  bichloride. 
The  operator  should  also  guard  against  his  own  infection  by  covering  even 
the  slightest  abrasion  of  the  cuticle  of  his  hands  with  a  film  of  flexible  col- 
lodion. 

Sterilization  of  the  Mouth  and  the  Teeth  of  the  Patient. — This 
comiDrehends  the  thorough  removal  of  all  calcareous  and  other  deposits 
upon  the  teeth ;  the  filling  of  all  carious  cavities,  either  permanently  or 
temx^orarily  ;  the  treatment  or  removal  of  all  suppurating  teeth  and  roots, 
and  a  liberal  use  of  antiseptic  mouth- washes,  like  a  saturated  solution  of 
boric  acid  ;  two  to  three  per  cent,  solutions  of  carbolic  acid  ;  the  Thiersch 
solution  (salicylic  acid  4  parts,  boric  acid  12  parts,  water  1000),  or  solutions 
of  listerine,  borolyptol,  pasteurine,  or  formol  1  to  100  of  the  forty  per  cent, 
solutions. 

Complete  sterilization  of  the  mouth  and  teeth,  however,  can  never  be 
attained  by  even  the  most  rigid  technique,  but  it  may  be  so  nearly  approxi- 


BACTERIOLOGY  OF  THE  MOUTH. 


105 


mated  as  to  greatly  reduce  tlie  dangers  from  infection  in  those  cases  \yliere 
the  continuity  of  the  soft  tissues  of  the  patient  has  to  be  broken. 

Sterilization  of  Instruments. — Instruments  of  every  kind  should  be 
thoroughly  sterilized  before  being  used  upon  a  patient.  This  may  be  most 
efficiently  done  by  boiling  in  water.    All  instruments  which  have  been  used 


Fig.  259. 


Instrument  sterilizer. 


about  the  mouth  of  a  patient  should  first  be  thoroughly  scrubbed  with 
warm  water  and  soap,  rinsed,  and  placed  in  a  sterilizer  and  boiled  for  at 


Fig.  260. 


Dental  mirror. 

least  five  to  ten  minutes.  Fig.  259  shows  a  very  neat  and  efficient  steril- 
izer, manufactured  by  the  S.  S.  White  Dental  Manufacturing  Company, 
which  is  sold  at  so  moderate  a  price  that  every  dentist  can  afford  to  possess 
one. 

When  the  instruments  are  removed  from  the  sterilizer  they  should  be 
wiped  dry  with  a  clean,  sterile  towel  while  they  are  still  hot.  By  this 
method  the  instruments  will  not  rust  or  tarnish.  Mouth-mirrors  are  some- 
times injured  by  the  boiling  x)rocess,  but  the  best  German  makes  stand 


106  OPERATIVE    DENTISTRY. 

the  ordeal  very  well,  and  will  often  last  for  months.  Ash  &  Sou  and  the 
S.  S.  Wliite  Dental  Manufacturing  ComiDany  supply  a  mirror  (Fig.  260) 
which  can  be  taken  out  of  the  frame,  which  makes  it  possible  to  sterilize 
this  part  of  the  instrument  by  placing  it  in  strong  solutions  of  carbolic 
acid,  while  the  frame  may  be  boiled.  The  safer  method,  however,  is  to 
boil  these  instruments  like  all  others,  and  when  the  glass  gives  out  replace 
it  by  a  new  one,  which  can  now  be  done  at  trifling  expense. 

Rubber  dam  may  be  kept  in  a  sterilized  condition  ready  for  use  by 
cutting  it  into  squares  of  suitable  size  and  placing  it  in  a  covered  glass  jar 
containing  a  1  to  3000  solution  of  mercuric  bichloride  and  washed  in 
sterilized  water  before  using.  To  guard  against  the  possibility  of  carry- 
ing infection  by  the  rubber  dam  from  one  patient  to  another  it  is  best 
never  to  use  the  dam  a  second  time,  except  upon  the  same  jpatient. 

Gauze  and  cotton  rolls  are  now  prepared  for  the  use  of  the  dentist,  which 
have  been  rendered  sterile  by  prolonged  heat.  These  should  be  kept  in 
boxes  with  tight-fitting  covers,  and  may  be  resterilized  at  any  time  by 
placing  them  in  a  sterilizing  oven  heated  to  250°  to  300°  F. 


CHAPTER  YI. 

EXAMINATION  OF  THE  TEETH  AND  MOUTH. 

The  imiDortauce  of  frequent  examinations  of  tlie  teeth,  and  oral  cavity 
as  a  i^ropliylactic  measure  against  the  development  of  disease  and  its  early 
discovery  cannot  be  too  strongly  urged  upon  the  public  or  upon  the  practi- 
tioner. The  old  adage  '^  that  an  ounce  of  pFCvention  is  worth  a  pound  of 
cure"  was  never  of  more  value  than  when  applied  to  the  prevention  of  dis- 
eases of  the  teeth  and  mouth. 

It  has  been  said  that  "the  highest  aim  of  the  healing  art  is  not  to  cure  dis- 
ease, but  to  prevent  it.''''  It  should  be,  therefore,  the  highest  duty  of  the 
dental  surgeon  to  strive  to  prevent  the  development  of  disease  within  the 
oral  cavity,  and  to  check  its  ravages  at  the  earliest  possible  moment,  so 
that  the  attendant  dangers  may  be  reduced  to  the  minimum.  In  order  to 
accomx)lish  this  much-to-be-desired  result  frequent  examinations  at  stated 
periods,  with  instruction  in  the  various  means  which  may  be  adopted  to 
keep  the  teeth  and  mouth  in  an  hygienic  condition,  will  be  absolutely 
necessary. 

This  system  of  frequent  x^eriodical  examinations,  to  be  most  effective, 
should  be  instituted  in  early  life,  commencing  with  the  little  children  as 
soon  as  the  deciduous  teeth  are  erupted. 

These  examinations  should  be  made  as  often  as  every  three  months  in 
the  case  of  little  children. 

At  these  sittings  the  child  should  be  taught  by  the  dentist  how  to 
cleanse  the  teeth.  This  first  instruction  in  the  art  may  be  rendered  the 
more  effective  by  the  operator  giving  the  child  an  object-lesson,  by  brush- 
ing his  own  teeth  in  its  presence.  The  little  patient  should  then  be  given 
a  brush  and  induced  to  imitate  the  brushing  process  by  watching  the  oper- 
ator as  he  applies  the  brush  to  the  teeth  and  makes  the  necessary  move- 
ments in  order  to  cleanse  all  the  surfaces  that  can  be  reached  by  this 
method.  The  nurse  or  the  mother  of  the  child  should  be  present,  and  in- 
structed to  follow  up  the  teaching  each  day,  adopting  the  same  methods 
of  instruction.  By  the  frequent  examinations  indicated  the  dentist  has 
opportunity  to  learn  whether  or  not  his  instructions  are  being  followed 
and  the  child  keei^ing  its  teeth  and  mouth  clean,  and  if  not,  it  gives  re- 
peated opportunities  to  correct  the  habit  of  neglect  and  impress  upon  the 
child  and  those  who  are  responsible  for  its  care  the  importance  of  a  hy- 
gienic condition  of  the  mouth  in  preventing  the  development  of  disease. 

In  the  light  of  the  prevailing  theory  of  disease,  and  of  the  constant  pres- 
ence within  the  mouth  of  so  many  forms  of  zymogenic  and  pathogenic 
micro-organisms,  the  practitioner  would  be  remiss,  indeed,  who  did  not 
impress  upon  his  clientele  the  great  value  of  a  hygienic  condition  of  the 

oral  cavity  as  a  i^rophylactic  measure. 

107 


108  OPERATIVE    DENTISTRY. 

At  eacli  periodical  visit  the  teeth  should  be  thoroughly  cleansed  and 
polished,  and  a  critical  examination  made  in  reference  to  the  presence  of 
caries,  diseased  conditions  of  the  gums,  or  other  abnormal  manifestations, 
appropriate  treatment  being  instituted  for  the  relief  of  the  individual  ail- 
ment. 

This  system  can  be  followed  with  older  children,  young  people,  and 
adults,  the  intervals  between  the  examinations  being  longer  or  shorter 
according  to  the  exigencies  of  each  individual. 

Children  and  youths  during  the  period  of  rapid  growth,  chlorotic  girls, 
and  pregnant  women  have  usually  an  increased  predisposition  to  dental 
and  oral  diseases ;  consequently  it  is  the  duty  of  the  dentist  to  acquaint 
them  with  the  fact  that  they  should  give  increased  attention  to  the  care  of 
their  teeth  and  mouth  if  they  would  maintain  these  organs  in  a  healthful 
condition. 

The  writer  has  found  in  his  own  x)ractice  that  his  clients  were  very  ap- 
preciative of  this  thoughtful  attention  to  their  physical  welfare,  and,  as  a 
rule,  gladly  co-operate  with  him  in  these  endeavors. 

In  order  that  no  case  requiring  especial  attention  may  be  overlooked,  it 
is  his  custom  at  the  sitting  given  for  the  examination  to  record  an  engage- 
ment upon  the  appointment-book  for  the  next  examination,  informing  the 
patient  that  a  notice  of  the  engagement  will  be  mailed  a  few  days  in  ad- 
vance of  the  time  when  it  becomes  due. 

These  engagements,  it  is  pleasant  to  say,  are  usually  kept  with  great 
X)unctuality  and  evident  appreciation. 

POSITION   OF   PATIENT   AND   OPERATOR. 

In  examinations  of  the  oral  cavity  good  light  is  a  siiie  qwi  non.  An 
examination  conducted  with  inadequate  light  is  of  little  value,  and  a  diag- 
nosis made  under  such  conditions  would  be  unreliable. 

The  patient  should  therefore  be  seated  in  a  suitable  chair  provided  with 
a  head-rest  capable  of  being  raised  and  lowered  and  moved  backward  and 
forward.  The  head  of  the  patient  should  be  so  positioned  that  when  the 
mouth  is  opened  the  light  will  fall  directly  within  it. 

The  operator  should  stand  upon  the  right  of  the  patient,  with  his  feet 
firmly  planted,  the  body  erect,  and  the  shoulders  thrown  back.  The 
chair  should  be  so  elevated  that  the  operator  can  maintain  this  position 
during  examinations,  and  as  far  as  possible  in  all  operations.  The  stoop- 
ing position  so  often  assumed  by  many  operators  is  not  conducive  to  full 
and  regular  breathing,  and  sooner  or  later  will  result  in  stooping  shoulders, 
contracted  chest,  and  pulmonary  complaints. 

The  operator  should  always  be  careful  to  breathe  through  the  nose. 
Habits  which  produce  a  bad  breath  should  never  be  indulged  in.  The 
contact  of  the  operator  with  the  patient  should  be  at  as  few  points  as  pos- 
sible. People  of  refinement  and  Culture  appreciate  the  efforts  of  the  den- 
tist to  guard  them  against  any  unnecessary  contact  of  person.  The  dental 
chairs  as  made  to-day  are  capable  of  such  changes  that  the  position  of  the 
patient  can  be  suited  to  any  requirement,  so  that  the  only  contact  that  is 
necessary  to  support  and  guard  the  hands  of  the  operator  is  that  of  resting 


EXAMINATION    OF    THE    TEETH    AND    MOUTH. 


109 


the  ends  of  the  ring  and  fourth  fingers  upon  some  portion  of  the  patient's 
face,  while  the  fingers  of  the  left  hand  control  and  guard  the  lips. 


Mouth-mirrors. 


INSTRUMENTS   USED   IN   EXAMINATIONS. 

The  instruments  and  appliances  which  are  necessary  to  a  thorough  ex- 
amination of  every  x)ortion  of  the  crown  of  each  individual  tooth  are  of 
several  kinds, — viz.,  mirrors,  magnify ing-glasses,  explorers,  electric  mouth- 
lamp,  floss-silk,  separators,  and  wedges. 

Mirrors. — Plane  and  concave  mirrors  are  both  necessary  in  a  critical 
examination  of  the  tissues  and  organs  of  the  oral  cavity.  The  plane  mir- 
ror gives  the  best  and  sharpest  image,  and  is  therefore  the  most  important 

means  of  obtaining  a  view  of  the 
^^^-  2^^-  defects  upon  those   surfaces   of 

the  teeth  which  are  not  in  a  di- 
rect line  of  vision. 

The  concave  mirror  gives  an 
enlarged  but  less  distinct  image  ; 
its  greatest  value  lies  in  its  power 
of  concentrating  the  rays  of  light 
and  illuminating  the  obscure  por- 
tions of  the  mouth.     These  in- 
struments should  always  be  in  the  very  best  condition.     A  dull  or 
scratched  mirror  cannot  give  a  clear  and  distinct  image  ;  such  in- 
struments should  therefore  be  discarded  if  the  operator  desires  to 
perform  perfect  operations.     The  most  satisfactory  mirrors  are 
those  backed  by  a  deposit  of  pure  silver  ;  they  cost  a  little  more 
than  those  '^  silvered"  with  tin  and  mercury,  but  the  added  cost 
is  more  than  repaid  by  the  brilliancy  of  the  surface  and  their 
greater  durability. 

Working  by  the  Reflected  Image. — Defects  in  the  teeth  so 
often  occur  in  positions  that  are  entirely  out  of  the  range  of  direct 
vision  that  it  becomes  necessary  in  order  to  bring  such  defects 
into  view  to  employ  the  reflecting  surface  of  the  mirror.  Many 
operations  have  to  be  performed  upon  the  teeth  in  which  the  only 
view  of  the  fleld  of  operation  is  obtained  from  the  reflected  image  in  the 
mouth-mirror. 

The  novice  will  at  first  find  such  operations  exceedingly  difficult  from 
the  fact  that  the  image  is  reversed,  and  that  each  movement  must  be  made 
in  a  direction  opposite  to  that  which  appears  to  be  correct.  Continued 
practice,  however,  eventually  overcomes  these  diificulties,  and  the  operator 
is  able  to  pass  from  a  direct  movement  to  a  reverse  one  with  apparently 
no  effort  of  the  will.  It  requires  years  of  x^ractice,  however,  and  a  high 
order  of  skill  to  make  perfect  operations  under  such  circumstances. 

Magnifying  Lenses. — These  instruments  are  of  very  great  value  in 
detecting  minute  defects  in  the  structure  of  the  enamel,  for  observing  the 
condition  of  fillings  previously  made,  or  the  progress  of  an  operation,  and 
in  the  examination  of  the  finished  filling. 


no 


OPERATIVE    DENTISTRY. 


The  most  usefiil  lenses  are  those  which  give  a  magnifying  power  of 
about  four  diameters.  They  may  be  either  the  watchmaker's  glass  (Figs. 
262  and  263),  held  in  position  before  the  eye  by  the  muscles  surrounding 
the  orbit,  or  the  lens  mounted  with  a  long  handle,  as  shown  in  Fig.  264. 

Fig.  2()3. 


Pointed  eye-glass. 


Eye-glass. 


Such  aids  to  the  critical  examination  of  the  teeth  are  indispensable  to 
the  careful  operator. 

The  magnifying  lens  may  be  employed  in  two  ways,  either  to  directly 
magnify  the  parts  which  are  in  the  direct  line  of  vision,  or  by  magnifying 
the  image  obtained  of  obscure  parts  by  reflection  upon  the  surface  of  the 
plane  mirror.  The  enlarged  image  obtained  in  this  manner  is  more  sharply 
defined  than  that  obtained  by  the  concave  mirror.     The  clouding  of  the 


Magnifying  lens. 


mirrors  and  lenses  may  be  obviated  by  coating  the  surfaces  with  pure 
glycerol. 

Explorers. — These  instruments  are  absolutely  necessary  for  the  detec- 
tion of  surface  defects  in  the  enamel  and  at  the  margins  of  fillings.  They 
are  "essentially  prolongations  of  the  fingers,  and  convey  imiDressions  by 
their  vibrations  to  the  tactile  nerves."  (Jack.)  They  are  principally  used 
to  search  out  defects  in  the  sulci,  fissures  and  grooves  formed  by  the  union 
of  the  developmental  lobes  of  the  enamel,  and  to  explore  those  surfaces 
which  cannot  be  brought  into  view  either  by  direct  or  reflected  light. 


EXAMINATION    OF    THE    TEETH    AND    MOUTH. 


Ill 


Several  differeut  forms  are  necessary  to  reach  all  parts  of  the  crown 
of  the  tooth,  some  straight,  others  of  various  curves  or  angles.  Fig.  265 
represents  some  of  the  common  forms.  These  may  be  made  by  the  prac- 
titioner himself,  or  he  can  obtain  them  from  the  supply  houses. 

No.  18  (American  gauge)  piano  wire  is  the  most  suitable  material  from 
which  to  construct  the  points.     The  temper  of  this  steel  wire  permits  it  to 

Fig.  265. 


Explorers. 


Fig.  2m. 


be  bent  into  any  desired  shape  necessary  for  this  purpose,  and  is  not  so 
hard  but  that  it  can  be  filed  to  any  degree  of  fineness  compatible  with  the 
required  strength  and  rigidity  of  such  an  instrument.  These  points  may 
be  mounted  in  wood  or  metal  handles,  to  suit  the  taste  and  ideas  of  the 
operator. 

Electric    Mouth-Lamp. — The   electric   mouth-lamp,   or   stomatoscope 
(Fig.  266),  is  a  great  aid  in  the  detection  of  defects  upon  the  proximal 

surfaces  of  the  teeth.  The  lamj)  should 
be  placed  within  the  mouth,  at  the  lin- 
gual surfaces  of  the  teeth,  and  the  cur- 
rent switched  on.  The  light  passing 
through  the  teeth  renders  them  in  a 
measure  translucent,  and  defects  ux^on 
their  surfaces  or  fillings  appear  as  dark 
shadows.  Transillumination  is  also  a  valuable  means  of  detecting  the 
non-vitality  of  the  pulp.  Devitalized  teeth  do  not  transmit  the  light  as 
readily  as  those  having  vital  pulps.  This  is  quite  easily  demonstrated 
with  the  electric  stomatoscope,  even  in  obscure  cases. 
In  detecting  diseases  of  the  antrum  it  is  indispensable. 


Electric  mouth-lamp  (reduced). 


112 


OPERATIVE    DENTISTRY. 


To  obtain  the  best  results  by  transillumination  a  dark  room  is  necessary, 
especially  for  examinations  of  tbe  antrum.  Fluid  or  solid  material  (tumors 
of  various  structure)  witliin  the  antrum  obstruct  the  transmission  of  light 
and  produce  an  opacity  which  can  be  detected  by  comparison  with  the 
normal  opposite  side  and  with  the  surrounding  tissues. 

Floss-Silk. — Floss-silk  which  has  been  just  sufficiently  waxed  to  bind 
the  fibres  together  is  a  very  valuable  adjunct  to  the  explorer  in  the  detec- 
tion of  proximal  surface  defects  of  the  enamel  and  in  determining  the 
condition  of  fillings.  In  a  normally  arranged  denture,  and  in  a  crowded 
condition  of  the  teeth,  the  finest  explorers  will  not  reach  the  approxi- 
mating surfaces ;  the  floss-silk  then  becomes  indispensable  as  an  added 
means  of  detecting  superficial  lesions  of  the  enamel,  which  is  indicated  by 
the  character  of  the  friction  produced  by  moving  it  back  and  forth  upon 
these  surfaces,  or  by  the  fraying  of  its  fibres.  Very  slight  defects,  how- 
ever, will  sometimes  remain  undetected ;  consequently  implicit  reliance 
must  not  be  placed  upon  its  negative  evidence,  and  other  means,  when 
doubt  exists,  must  be  used  to  establish  the  conditions  of  these  surfaces 
beyond  j)erad venture. 

Fig.  267. 


Parr's  universal  separator. 

Separators  and  "Wedges. — Separation  of  the  teeth  for  the  purposes 
of  examination  or  in  preparation  for  filling  may  be  accomplished  in  several 
ways.  Immediate  separation  may  be  obtained  by  the  use  of  the  Parr, 
Perry,  or  other  screw  or  wedge  separators  (Figs.  267,  268),  or  by  driving 
a  wooden  wedge  between  the  teeth,  or  it  may  be  accomplished  more  slowly 
by  the  use  of  waxed  linen  tape  or  india-rubber  strips  forced  between  them. 


THE   EXAMINATION. 

A  critical  examination  of  the  oral  cavity  should  usually  be  preceded 
by  a  thorough  cleansing  and  i^olishing  of  the  teeth,  as  few  mouths  are  so 
scrupulously  clean  that  this  procedure  will  not  make  the  after-examination 
more  sure  and  thorough. 

Certain  parts  of  the  teeth  are  more  liable  to  be  attacked  by  caries  than 
others ;  these  are  in  locations  which  give  ready  lodgement  and  retention  to 


EXAMINATION    OF    THE    TEETH    AND    MOUTH. 


113 


food  Mhris  and  sedimentary  deposits,  and  in  wliicli  fluids  are  retained  or 
suspended  by  capillary  attraction, — viz.,  the  proximal  surfaces^  the  sulci 
and  fissures,  and  the  labial  and  buccal  surfaces;  the  relative  liability  to 
caries  being  in  the  order  named. 

In  conducting  an  examination  of  the  mouth  it  is  best  to  proceed  in  an 
orderly  manner,  that  no  part  may  be  overlooked,  and  that  every  part 
should  receive  due  attention. 

First.  Notice  the  appearance  of  the  patient  as  to  the  state  of  health. 

Secondly.  A  general  view  should  be  taken  of  the  whole  oral  cavity,  in- 
cluding the  gums,  the  mucous  membrane  of  the  cheeks,  lips,  palate,  and 
fauces  ;  the  tongue  and  the  character  of  the  oral  secretions,  and  any  devia- 
tion from  the  normal  carefully  noted,  as  these  all  have  a  more  or  less 
direct  bearing  upon  the  hygienic  condition  of  the  teeth.  They  are  also 
indicative  of  various  constitutional  states  and  tendencies  that  influence  the 
course  and  character  of  the  dental  diseases,  the  consideration  of  which 


Fig.  268. 


Perry's  two-bar  separators. 


should  enter  largely  into  the  question  which  must  always  be  decided,  as  to 
whether  the  best  interests  of  the  patient  will  be  conserved  by  the  intro- 
duction of  temporary  or  permanent  fillings. 

Thirdly.  Beginning  at  the  median  line  of  each  denture,  a  critical  inspec- 
tion of  every  portion  of  each  tooth  should  be  instituted  by  the  aid  of  the 
various  appliances  just  described,  and  each  defect  carefully  noted.  Par- 
ticular attention  should  be  given  to  those  locations  in  which  caries  is  most 
liable  to  be  developed.  The  condition  of  all  previous  operations  should 
be  ascertained,  and  if  imperfections  exist  they  should  be  recorded,  as 
should  also  the  presence  of  salivary  calculus,  exposed  pulps,  devitalized 
teeth,  pyorrhoea  alveolaris,  dento- alveolar  abscess,  the  location  of  super- 
numerary teeth,  irregularities,  and  teeth  which  have  been  lost. 

For  the  purpose  of  preserving  the  results  of  these  examinations 
various  forms  of  charts  have  been  devised,  with  special  signs  adapted  to 
simplify  the  work  of  making  the  record,  any  one  of  which  will  adequately 
serve  the  purpose.  The  operator  can,  however,  use  any  of  the  diagrams 
which  are  found  in  the  dental  registers,  inventing  or  adopting  such  signs 


114  OPEEATIVE    DENTISTRY. 

as  seem  best  to  him  as  a  means  of  makiDg  a  rapid,  expressive,  and  reliable 
record. 

These  temporary  records  should  be  preserved  until  the  required  opera- 
tions and  treatment  have  been  completed,  and  the  record  of  each  trans- 
ferred to  the  permanent  register. 

The  careful  registration  of  all  operations  of  whatever  character  cannot 
be  too  strongly  urged  upon  the  student  and  young  practitioner,  for  as  time 
goes  on  they  become  invaluable  as  a  means  of  reference. 

No  one  can  remember  the  exact  condition  of  each  and  every  denture 
upon  which  he  has  been  called  to  operate  in  the  past ,  nor  the  circumstances 
or  diflaculties  which  surrounded  the  performance  of  a  certain  operation, 
the  condition  of  the  pulp,  or  of  the  root-canals,  etc.,  but  many  times  such 
information  would  be  of  incalculable  benefit  to  the  patient  and  operator  in 
the  future  treatment  of  the  case. 


CHAPTEE    VII. 

DENTAL   CAEIES. 

Definition. — Caries  (Latin,  caries,  rotten). 

Synonymes. — Caries  dentes  ;  Caries  dentium  ;  Dental  decay  ;  Dental  gangrene. 

Dental  caries  may  be  defined,  pathologically  as  a  progressive  molecu- 
lar disintegration  of  the  structural  elements  of  the  tooth,  beginning  with 
the  solution  of  the  inorganic  substances  by  the  action  of  lactic  acid  formed 
within  the  mouth  by  fermentation,  and  terminating  with  the  dissolution 
of  the  organic  matrix  through  the  solvent  action  of  the  saprophytic  micro- 
organisms. 

Magitot  defined  dental  caries  from  its  clinical  aspects  as  "  a  progressive 
softening  and  continuous  destruction  of  the  hard  structures  of  the  teeth, 
advancing  constantly  from  the  exterior  to  the  interior,  and  causing  a 
gradual  disappearance  of  a  more  or  less  extensive  portion,  or  even  the 
whole  of  the  organ." 

Introduction. — Dental  caries  is,  without  doubt,  the  most  common  of 
all  the  diseases  to  which  the  human  body  is  heir,  and  from  which  very  few 
persons  among  civilized  nations  entirely  escape.  It  seems  to  be  pre-emi- 
nently a  disease  of  higher  civilization,  as  it  is  most  common  among  those 
nations  which  are  recognized  as  having  the  highest  civilization,  and  yet 
no  race  or  tribe  of  men  yet  discovered,  whether  savage,  barbarous,  semi- 
civilized  or  civilized,  ancient  or  modern,  have  ever  wholly  escaped  it. 
Archaeology,  history,  and  anthropology  all  prove  the  correctness  of  the 
statement.  Evidences  are  not  lacking  that  the  prehistoric  man  suffered 
from  dental  caries,  alveolar  abscesses,  and  other  dental  diseases.  Many 
of  the  Egyx^tian  mummies  found  in  our  great  museums  show  well-marked 
evidences  of  caries  and  other  diseases  of  the  teeth. 

Herodotus  tells  us  that  the  Egyptians  had  doctors  for  the  eyes,  doctors 
for  the  ears,  and  doctors  for  the  teeth,  etc.,  showing  that  they  had  need 
of  specialists  in  these  directions.  Lancets  and  forceps  for  the  extraction 
of  teeth  are  to  be  found  in  museum  collections  of  Egyptian  antiquities. 
Artificial  teeth  have  been  found  in  the  mouths  of  mummies,  and  state- 
ments have  been  made,  though  not  very  well  authenticated,  that  gold 
fillings  had  likewise  been  discovered  in  the  teeth.  They  evidently  pos- 
sessed some  knowledge  of  dental  therapeutics,  for  they  applied  the  juice  of 
the  poppy,  pepper,  spices,  etc.,  to  relieve  the  pain  of  toothache,  and  in  the 
later  stages  of  this  disease  and  in  the  early  stage  of  alveolar  abscess  ap- 
plied the  actual  cautery  and  counter-irritation.  One  mummy  in  the 
British  Museum,  dating  back  to  a  period  about  2800  e.g.,  or  more  than 

115 


116  OPEEATIVE    DENTISTRY. 

four  thousand  five  hundred  years,  shows  undisputed  evidence  of  dental 
caries  and  other  dental  lesions. 

That  dental  caries  and  the  lesions  which  result  therefrom  were  com- 
mon among  the  Greeks  in  the  earlier  and  later  periods  of  their  history- 
there  is  abundant  proof.  The  early  Greek  physician  gave  considerable 
attention  to  the  diseases  of  the  teeth.  During  the  latter  part  of  the 
Greek  eiDoch  the  fop  or  dude  gave  great  attention  to  the  care  of  his  teeth, 
and  was  very  proud  of  having  them  look  fine  and  white.  His  more 
stalwart  brethren  ignored  such  attention  to  their  personal  appearance,  con- 
sidering it  effeminate  and  only  suited  to  women  and  fools.  Their  physi- 
cians treated  odontalgia  after  the  manner  of  the  Egyptians.  Cicero 
credits  the  third  ^sculapius  with  inventing  an  instrument  for  extracting 
the  teeth.  Diodes  opposed  extraction  and  treated  toothache  by  medica- 
tion, Strabo  mentions  formulae  for  the  relief  of  odontalgia  and  cosmetics 
for  the  care  of  the  teeth.  Dr.  Schliemann,  the  great  Greek  archaeologist, 
has  reported  that  in  his  excavations  at  the  site  of  ancient  Troy  several 
of  the  crania  found  there  exhibited  teeth  with  carious  cavities,  some  of 
which  had  been  filled  with  metals,  lead  particularly. 

Coming  next  to  the  old  Eoman  civilization,  the  historical  proof  is 
abundant  that  dental  caries  and  other  dental  diseases  must  have  been  com- 
mon among  them,  and  that  they  practised  the  art  of  filling  carious  teeth 
and  of  inserting  artificial  teeth  carved  from  bone  and  ivory. 

Celsus  gives  formulae  for  the  treatment  of  toothache  resulting  from 
caries.  These  were  compounded  from  resinous  and  aromatic  substances 
combined  with  the  juice  of  the  poppy,  saffron,  sulphur,  etc.,  and  were  to 
be  applied  to  the  carious  cavity  in  the  painful  tooth.  He  also  advised 
the  use  of  blisters  and  poultices  for  the  cure  of  alveolar  abscess,  and  in- 
sisted upon  general  medication  in  conjunction  with  the  local  treatment. 
Celsus  has  been  given  the  credit  of  inventing  the  art  of  filling  teeth  with 
gold  and  other  substances  150  to  180  a.d.  Archaeologic  proof  of  the  fact, 
however,  that  the  art  of  filling  teeth  was  practised  by  the  ancient  Eomans 
is  entirely  lacking.  Whether  this  is  due  to  the  quite  general  custom  of 
burning  the  dead,  and  thus  destroying  the  evidence,  or  that  it  had  no 
real  foundation  in  fact,  is  a  question  that  may  never  be  settled. 

RESULTS   OF   THE   EXAMINATION   OF   ANCIENT   CRANIA. 

Mummery  has  examined  and  tabulated  a  very  large  number  of  ancient 
crania  in  relation  to  the  prevalence  of  dental  caries  with  the  following 
results  :  Ancient  Britons  of  dolichocephalic  type,  2. 94  per  cent.  ;  of  brachy- 
cephalic  type,  21.87  per  cent.  ;  Eomano -Britons,  28.67  per  cent. ;  Anglo- 
Saxons,  15.78  i)er  cent.  ;  ancient  Egyptians,  41.66  jier  cent.  It  will  thus 
be  seen  that  the  i^revalence  of  caries  bears  a  very  close  relationship  to  the 
degree  of  civilization  and  the  luxurious  habits  indulged  in  by  these  ancient 
nations. 

Professor  Broca  examined  a  large  number  of  crania  of  the  ancient 
peoj)les  of  Europe,  and  discovered  that  caries  of  the  teeth  was  much  less 
frequent  than  at  the  present  time,  and  that  they  were  also  very  much  worn 
down  from  attrition. 


DENTAL   CARIES.  117 

Dr.  Patrick  instituted  an  examination  of  all  the  preliistoric  crania  to 
be  found  in  the  various  important  museums  in  America,  composing  Pea- 
body  Museum  of  Harvard  University,  the  Army  Medical  Museum,  Wash- 
ington, D.  C,  the  collection  of  Dr.  Samuel  G.  Morton  in  the  Academy  of 
Naturai  Sciences,  Philadelphia,  the  collection  in  the  Davenport  Academy 
of  Science,  Iowa,  the  collection  in  the  Museum  of  the  Chicago  Medical 
College,  Illinois,  and  a  collection  obtained  from  an  ancient  burial  mound 
near  the  great  Cohokia  Temple  Mound  in  St.  Clair  County,  Illinois,  now 
in  the  Museum  of  the  Missouri  Historical  Society  at  St.  Louis. 

These  examinations  cover  a  wide  range  of  subjects,  including  every 
evidence  of  the  diseases  and  anomalies  of  the  teeth  and  jaws,  and  form  a 
wonderful  mine  of  information,  the  importance  of  which  can  hardly  be 
over-estimated,  "for  there  is  not  a  question  that  may  arise  in  morphology, 
histology,  or  physiology  on  which  the  facts  revealed  in  this  investigation 
will  not  shed  some  light. "    (Patrick.) 

The  crania  examined  included  South  Americans,  Central  Americans, 
North  Americans,  Europeans,  Pacific  and  Sandwich  Islanders,  Egyptians, 
and  Asiatics.  Dental  caries  was  found  to  be  prevalent  in  all,  but  in  a 
varying  percentage,  which  seemingly  is  governed  by  the  habits  of  life 
and  the  state  of  civilization. 

The  South  Americans  included  Peruvians,  Chilians,  Tierra  del  Fuegians, 
and  Guanches.  In  this  group  6719  teeth  were  examined  ;  2462  were  dis- 
eased, or  36.75  per  cent.  Number  of  carious  teeth,  390,  or  5.804  per  cent. 
The  Central  Americans  were  composed  of  Mexicans,  Guatemalans,  and 
Nicaraguans.  The  teeth  examined  numbered  930,  and  of  this  number 
250  were  diseased,  or  26.8  per  cent.  Caries  was  present  in  44,  or  4.872 
per  cent. 

The  North  Americans  included  Esquimaux,  Alaskans,  and  various  tribes 
from  nearly  every  section  of  the  United  States.  In  this  very  large  group 
27,362  teeth  were  examined  :  3811  showed  evidences  of  disease,  or  21.4  per 
cent.     Of  this  number,  1394  were  carious,  or  5.093  per  cent. 

The  Europeans  included  Germans,  French,  English,  Swedes,  Irish, 
Greeks,  Italians,  Anglo-Americans,  and  a  few  modern  soldiers.  The  num- 
ber of  teeth  examined  was  3422.  Of  this  number,  1373  were  found  to  be 
diseased,  or  40.4  per  cent.  The  number  of  carious  teeth  was  242,  or  7.079 
per  cent. 

The  Pacific  Islanders  included  Sandwich  Islanders,  Australians,  New 
Zealanders,  and  Tchoolabees.  In  this  group  2738  teeth  were  examined, 
and  417  were  found  diseased,  or  15.25  per  cent. ;  118  showed  caries,  or  4.309 
per  cent. 

The  Egyptians  included  Africans.  The  number  of  teeth  examined  was 
3306  ;  of  these,  689  were  found  diseased,  or  20.8  per  cent.  Of  this  number, 
113  were  carious,  or  3.418  per  cent. 

The  Asiatics  included  Malays,  Chinese,  Japanese,  Armenians,  Hindoos, 
and  Burmese.  In  this  group  2180  teeth  were  examined,  and  336  showed 
evidences  of  disease,  or  15.4  per  cent.  Number  of  carious  teeth,  45,  or 
2.064  per  cent. 

Miller  maintains  that  in  the  meat- eating  races  caries  is  far  less  preva- 


118  OPERATIVE    DENTISTRY. 

lent  than  in  tliose  wbicli  subsist  largely  upon  mixed  foods,  and  presents  as 
evidence  the  fact  that  the  dolichocephalic  ancient  Britons,  who  subsisted 
in  all  probability  almost  exclusively  upon  a  meat  diet,  x)resented  in  the 
crania  examined  only  about  three  per  cent,  of  dental  caries,  while  in  the 
brachy cephalic  ancient  Briton,  Eomano-Briton,  Anglo-Saxon,  and  Egyptian, 
all  of  whom  subsisted  upon  a  mixed  diet,  the  percentage  of  caries  ranged 
from  fifteen  to  forty-one  per  cent.  Among  the  modern  aboriginal  flesh-eat- 
ing races  he  cites  the  Esquimaux,  K"orth  American  (coast)  Indians,  North 
American  (interior)  Indians,  South  Americans,  Feejee  Islanders,  ISTew  Zea- 
lauders,  and  Lapps.  These  have  all  a  low  percentage  of  dental  caries. 
The  Esquimaux,  who  live  almost  exclusively  upon  meat  and  fish,  have 
but  2.46  per  cent,  of  caries,  while  the  E"orth  American  (interior)  Indians, 
whose  diet  is  mostly  meat,  but  using  some  vegetables,  have  an  average 
of  9.09  per  cent,  this  being  the  highest  percentage  in  this  group  of 
aboriginal  meat-eating  races. 

Magitot  could  find  in  the  anthropologic  series  of  the  museums  of 
Paris  no  examjples  of  dental  caries  among  the  crania  of  the  Mexicans,  Pe- 
ruvians, or  Patagonians,  none  among  the  aborigines  of  Australia,  Mada- 
gascar, Xew  Caledonia,  etc.,  nor  among  the  Malay  and  Javanese  crania  of 
Professor  Wrolik.  He  also  states  that  the  African  and  Arab  races  are 
remarkable  for  the  soundness  of  their  teeth,  the  Caucasian  race  being  the 
opposite  of  this,  while  the  Mongolian  race  seems  to  hold  a  middle  po- 
sition. The  Icelanders,  according  to  recent  investigations,  seem  to  be 
nearly  exempt  from  the  disease. 

The  investigations  of  Barrett,  conducted  for  the  same  purpose,  also  lead 
to  the  same  conclusions. 

Prevalence. — Statistics  upon  the  prevalence  of  dental  caries  among 
the  nations  of  the  present  civilization  are  by  no  means  numerous,  and 
nearly  all  of  thos^  which  have  been  taken  deal  more  with  the  question  of 
the  frequency  of  caries  in  individual  teeth  and  groups  of  teeth  than  with 
the  subject  of  the  percentage  of  people  who  are  sufferers  from  the  disease. 
That  the  percentage  is  very  large  and  apparently  upon  the  increase  there 
is  not  the  shadow  of  a  doubt  in  the  minds  of  those  best  qualified  to  judge, 
and  yet  without  statistics  carefully  prepared  from  many  sources,  at  stated 
periods  and  under  varying  conditions  of  life,  any  statement  that  might  be 
made  must  be  taken  as  one  of  personal  opinion  only. 

It  is  generally  conceded,  however,  that  females  are  distinctly  more 
liable  to  dental  caries  than  are  males. 

Magitot  expressed  the  relative  frequency  of  caries  in  the  female  by  the 
ratio  of  three  to  two  as  compared  with  the  male.  Harris  places  the  ratio 
much  higher,  claiming  that  it  occurs  in  the  female  three  times  as  often  as 
it  does  in  the  male.  Married  women  are  considerably  more  liable  to  the 
disease  than  the  unmarried,  as  the  period  of  pregnancy  and  lactation  are 
especially  favorable  to  the  development  and  progress  of  the  disease. 

In  reference  to  the  relative  frequency  of  caries  among  the  men  of 
France  who  were  subject  to  military  duty,  Magitot  introduces  the  statistics 
of  the  war  office.  These  statistics  deal  only  with  young  men  of  twenty 
years  of  age,  but  they  may  be  fairly  considered  as  showing  the  regular 


DENTAL   CARIES.  119 

percentage  of  badly  defective  dentures  for  the  whole  mass  of  the  adult 
male  population. 

The  French  law  gave  exemption  from  military  service,  first,  when  there 
was  loss  or  caries  of  the  incisors  or  canines  of  one  of  the  jaws,  and  secondly, 
when  there  was  loss  or  caries  or  a  bad  condition  of  the  majority  or  of  a 
large  number  of  the  other  teeth. 

The  exemptions  from  military  service  from  1837  to  1849,  inclusive, — 
thirteen  years, — by  reason  of  imperfect  dentures,  was  25,918  out  of 
3,295,202,  which  is  equivalent  to  an  annual  average  of  785  in  every 
100,000  examined.  The  annual  maximum  was  895  in  1837  ;  the  minimum, 
643  in  1847,  or  an  average  percentage  of  7.85.  If  there  be  added  to  this 
the  increased  percentage  of  caries  in  females,  using  "Magitot's  figures  of  a 
ratio  of  three  to  two,  and  taking  an  equal  number  of  males  and  females, 
the  percentage  for  the  entire  population  would  be  9.15.  This,  however, 
does  not  fairly  represent  the  average  percentage  of  persons  affl.icted  with 
caries ;  in  fact,  it  falls  far  short  of  the  actual  condition,  as  all  of  those  who 
were  received  were  not  free  from  dental  defects,  but  simply  were  not  suffi- 
ciently defective  under  the  law  to  give  exemption. 

Statistics  which  more  clearly  represent  the  true  condition  of  the  preva- 
lence of  dental  caries  among  civilized  nations  is  to  be  found  in  the  report 
of  the  School  Committee  of  the  British  Dental  Association  (Tomes),  fol- 
lowing the  examination  of  the  mouths  of  3368  boys  and  girls  at  the  Han- 
well  and  Sutton  schools,  and  at  the  Exmouth  training  shi]3.  Out  of  this 
number  only  twenty-three  per  cent,  had  sound  dentures,  or,  in  other  words, 
seventy-seven  per  cent,  were  afflicted  with  caries.  The  number  of  perma- 
nent teeth  found  to  be  carious  was  4543,  while  about  an  equal  number 
of  temporary  teeth  were  found  in  the  same  condition.  These  boys  and 
girls  ranged  from  three  and  a  half  to  seventeen  years  of  age,  but  the 
majority  were  from  five  to  fourteen. 

The  number  of  boys  upon  the  Exmouth  training  ship  was  480,  largely 
recruited  from  these  schools,  the  average  age  being  fourteen  years  ;  twenty- 
four  per  cent,  had  perfect  dentures,  or,  seventy-six  per  cent,  had  carious 
teeth  ;  44.9  per  cent,  had  from  one  to  four  carious  permanent  teeth,  22.9 
per  cent,  had  from  five  to  eight,  and  5.25  per  cent,  had  more  than  eight 
carious  permanent  teeth.  At  the  Hanwell  schools,  out  of  903  children 
examined  at  the  age  of  eight  years,  83  furnished  127  carious  permanent 
teeth,  all  first  molars ;  at  the  age  of  twelve  years  90  children  had  244 
carious  permanent  teeth ;  the  percentage  of  unsound  permanent  teeth  in 
this  number  of  children  at  the  age  of  six  is  53,  at  the  age  of  twelve,  271, 
and  at  the  age  of  fourteen,  300. 

The  Association  Committee  made  an  attempt  to  compare  the  condition 
of  the  teeth  of  the  children  in  the  poor^  and  high-class  schools,  but  the 
numbers  in  the  latter  were  not  sufficiently  numerous  to  give  conclusive 
results,  as  only  205  children  of  this  class  were  examined,  and  these  did  not 
compare  favorably  with  those  less  fortunately  placed. 

Another  interesting  fact  in  reference  to  the  prevalence  of  caries  is  the 
wide  difference  existing  in  the  relative  frequency  of  the  disease  in  the  upper 
and  the  lower  jaw,  and  between  individual  classes  and  groups  of  teeth. 


120  OPERATIVE    DENTISTRY. 

The  diflferences  between  the  right  and  left  sides  are  so  small  as  to  be  of 
no  jpai'ticular  moment ;  hence  in  the  following  tables  this  difference  will 
only  be  noted  in  the  footings. 

Ottofy  computed  from  an  examination  of  14,644  teeth  of  American 
public-school  children  that  caries  was  i^resent  in  27.33  per  cent,  in  males 
and  32.67  per  cent,  in  females. 

The  teeth  examined  comprised  5100  deciduous  and  9544  permanent 
teeth. 

Of  the  5100  deciduous  teeth  examined  the  following  percentage  were 
found  carious : 

Lower  central  incisors 0.03 

Lower  lateral  incisors 0.09 

Upper  central  incisors   1.32 

Upper  lateral  incisors 1.42 

Lower  cuspids 1.99 

Upper  cuspids    2. 78 

Lower  first  molars 6.52 

Upper  first  molars. . .    6. 72 

Lower  second  molars 7.80 

Upper  second  molars 9. 77 

Of  the  9544  permanent  teeth  examined  the  following  percentage  were 
found  carious  : 

Lower  cuspids 0.01 

Lower  lateral  incisors  0.04 

Lower  central  incisors 0.05 

Upper  cuspids. . . 0.05 

Lower  first  bicuspids 0. 10 

Upper  second  bicuspids 0.28 

Lower  second  bicuspids    0.30 

Upper  first  bicuspids  0.38 

Upper  lateral  incisors 0.55 

Upper  central  incisors 0.85 

Upper  second  molars , 1.25 

Lower  second  molars  1.57 

Upper  first  molars 7.20 

Lower  first  molars 7.70 

This  table  gives  a  better  showing  for  the  American  public- school 
children  than  that  furnished  by  the  committee  of  the  British  Dental  Asso- 
ciation of  the  condition  of  the  teeth  of  the  children  found  in  the  Hanwell 
and  Sutton  schools.  This  difference  is  explained  by  the  fact  that  the 
children  in  the  Hanwell  and  Sutton  schools  were  from  the  poorest  class 
of  English  society,  while  the  American  public  schools  are  patronized  by 
all  classes  of  society. 

The  Schleswig-Holstein  Dental  Association,  in  a  recent  investigation  * 
into  the  prevalence  of  dental  caries  among  school- children  in  Northern 
Germany,  conducted  by  Dr.  Greve,  of  Lubeck,  presents  an  extended 
report  upon  the  subject,  of  which  the  following  table  is  a  summary  : 

*  Cor.  Blatt.  fiir  Zahn,  July,  1899. 


DENTAL   CARIES. 


121 


Age. 


Six  to  eight  years 

Nine  to  ten  j'ears 

Ten  to  twelve  years. . . 
Twelve  to  fifteen  years 


Number 
Examined. 

Perfect  Teeth. 

Carious 

Number. 

Per  cent 

Number. 

6060 

407 

6.8 

5653 

4990 

268 

3.4 

4732 

3518 

149 

4.3 

3369 

5157 

172 

5.5 

4985 

Per  cent. 
93.2 
96.5 
95.7 
94.5 


Of  the  19,725  children  examined,  ninety-five  per  cent,  showed  dental 
caries. 

It  was  also  noted  that  there  were  372  anomalies  of  various  characters, 
including  harelip,  cleft  palate,  irregularities,  Y-shaped  jaws,  and,  singu- 
lar as  it  may  seem,  only  one  case  of  congenital  syphilis  was  found. 

The  investigation  covered  the  children  of  nineteen  towns. 

The  boys  were  found  to  have  somewhat  better  teeth  than  the  girls,  the 
difference  being  about  three  per  cent,  in  favor  of  the  boys. 

Magitot  places  the  relative  frequency  of  caries  in  the  uj)per  and  lower 
jaw  respectively  in  the  proportion  of  three  to  two. 

This  author  presented  the  following  analysis  of  ten  thousand  cases,  from 
which  the  above  conclusion  is  drawn  : 


Central  incisors 


Lateral  incisors. 


Canines 


642 1 

777 1 


515 


First  bicuspids 1,310  < 

Second  bicuspids 1,310  < 


First  molars 3,350 

1,736 1 


Second  molars. 


Third  molars 


360 


612  upper. 
30  lower. 

747  upper. 
30  lower. 

445  upper. 
70  lower. 

940  upper. 

370  lower. 

810  upper. 

500  lower. 
1,540  upper. 
1,810  lower. 

690  upper. 
1,046  lower. 

220  upper. 

140  lower. 


Total 10,000    10,000 

Upper 6,004-.  Right  side '^'''^^li 

Lower 3,996  /  ^^'^^^        Left  side 5,209  /  ^^' 


000 


Hitchcock,  in  Wedl's  ^^  Pathology  of  the  Teeth,"  presents  the  follow- 
ing table  of  twenty  thousand  cases  prepared  from  records  of  fillings  and 
extractions  in  which  the  ratio  of  frequency  of  caries  in  the  upper  teeth  is 
placed  at  1.9  to  1  in  the  lower,  or  nearly  two  to  one  : 

Central  incisors..    2,189{    2,101  upper. 

<-        88  lower. 

Lateral  incisors 1,954  <      '   ^„  , 

I       127  lower. 

Canines    1,261 1    ^'^^^  ."PP"^" 

t-       203  lower. 

First  bicuspids 2,073|    1.588  upper. 

t.      4So  lower. 


122  OPEEATIVE    DENTISTRY. 

Second  bicuspids 2,585 1 


First  molars 4,399 

Second  molars 3,615  | 

Third  molars 1,924 1 


1,715  upper. 

870  lower. 
2,273  upper. 
2,126  lower. 
1,675  upper. 
1,940  lower. 

899  upper. 
1,025  lower 


Total 20,000    20,000 

Upper 13,136  \  go  OOO        ^'^^*  ^'^^ ^'^'^^^  \  20,000 

Lower 6,864  i      '  Leftside 9,849  J 

Tomes  presents  a  table  of  2638  cases  of  extractions  on  account  of  caries 
or  its  consequences,  as  follows  : 

Central  incisors 25 

Lateral  incisors 62 

Canines 36 

First  bicuspids •  227 

Second  bicuspids 393 

First  molars 1090 

Second  molars 575 

Third  molars 230 

Total 2638 

A  table  prepared  by  Pare  and  Wallis  from  tbe  records  of  30,012  cases 
of  extractions  at  Guy's  Hospital  gives  the  following  results  in  percentage  : 

First  molars 10,891,  or  36.30  per  cent. 

Second  molars 5,904,  or  19.68  per  cent. 

Second  bicuspids 4,179,  or  13.93  per  cent. 

First  bicuspids 3,212,  or  10.70  per  cent. 

Third  molars 2,639,  or    8.76  per  cent. 

Lateral  incisors 1)202,  or    4.00  per  cent. 

Canines 1,098,  or    3.66  per  cent. 

Central  incisors 884,  or    2.94  per  cent. 

Separating  the  upper  from  the  lower  teeth  in  this  table  of  cases.  Pare 
and  Wallis  have  given  us  the  following  percentage  for  the  individual  teeth  : 

Lower  first  molars 5632,  or  18.7  per  cent. 

Upper  first  molars 5259,  or  17.4  per  cent. 

Lower  second  molars 3489,  or  11.62  per  cent. 

Upper  second  bicuspids 2503,  or    8.33  per  cent. 

Upper  second  molars 2415,  or    8.04  per  cent. 

LTpper  first  bicuspids 2288,  or    7.623  per  cent. 

Lower  second  bicuspids 1676,  or    5.58  per  cent. 

Lower  third  molars 1322,  or    4.4  per  cent. 

Upper  third  molars 1317,  or    4.38  per  cent. 

Upper  lateral  incisors 1013,  or    3.37  per  cent. 

Lower  first  bicuspids 924,  or    3.07  per  cent. 

Upper  canines 861,  or    2.86  per  cent. 

Upper  central  incisors 754,  or    2.51  per  cent. 

Lower  canines 237,  or    0. 78  per  cent. 

Lower  lateral  incisors 189,  or    0.62  per  cent. 

Lower  central  incisors 133,  or    0.443  per  cent. 


DEXTAL    CARIES.  123 

In  these  tables  it  will  be  noticed  that  the  first  permanent  molars  are 
most  susceptible  to  those  influences  which  produce  decay,  and  that  the 
lower  molars  are  slightly  more  susceptible  (18.7  per  cent.)  than  the  upper 
(17.4  per  cent.),  the  difference  being  1.3  per  cent.  The  second  lower  mo- 
lars stand  next  in  susceptibility  ;  these  are  followed  by  the  upper  second 
bicuspids  and  the  upper  second  molars,  and  so  on  down  the  list  until  the 
lower  canines,  laterals,  and  centrals  are  reached,  in  which  the  percentage 
of  decay  is  so  small  as  to  almost  constitute  immunity. 

The  agency  which  gives  this  i)rotection  or  immunity  is  thought  by 
some  authorities  to  be  the  secretion  of  the  submaxillary  glands,  by  others 
the  presence  of  fluid  in  the  floor  of  the  mouth,  which  is  kept  in  constant 
motion  by  the  movements  of  the  tongue,  and  thus  retarding  the  jjrocess  of 
fermentation  ;  but  whatever  it  is,  the  protective  effect  is  not  efficacious  in 
the  posterior  part  of  the  mouth,  and  it  will  be  noticed  that  the  agency 
grows  less  and  less  efficacious  from  the  incisors  backward. 

From  the  foregoing  pages  it  will  be  readily  seen  that  all  of  the  inves- 
tigations in  reference  to  the  i^revalence  of  dental  caries  among  ancient 
and  modern  races  conclusively  proves  that  the  disease  has  always  been 
present,  at  least  as  far  back  as  evidence  can  be  obtained  from  written  his- 
tory and  archseologic  research  ;  that  it  was  comparatively  rare  among  abo- 
riginal tribes  and  nations  who  per  force  lived  a  simple  life  ;  while  among 
those  ancient  and  modern  races  and  nations  who  had  attained  to  a  high 
state  of  civilization,  with  its  attendant  luxuries  and  enervating  habits,  it 
has  been  very  common,  while  at  the  present  time,  as  proved  by  the  statis- 
tics recently  gathered,  it  is  increasing  in  a  most  alarming  manner. 

ETIOLOGY. 

The  causes  which  are  responsible  for  the  universal  prevalence  of  this 
disease  are  many  and  varied.  These  are  divided  into  two  general  groups, 
— viz.  : 

Indirect  or  predisposing,  and  direct  or  exciting  causes.  The  former  deals 
with  certain  conditions  which  have  been  established  beforehand,  through 
inheritance  of  constitutional  tendencies  or  special  dyscrasia  and  local  de- 
velopmental defects  or  anomalies ;  while  the  latter  treats  of  those  phe- 
nomena which  are  the  active  agents  in  establishing  and  maintaining  the 
progress  of  the  disease- 
Predisposing  Causes. — The  conditions  which  are  here  enumerated  as 
predisposing  causes  of  dental  caries  may  be  divided  into  two  groujDS, — 
viz.,  constitutional  and  local. 

The  constitutional  predisposing  causes  are  : 

Environment. 

Climatic  influences. 

Miscegenation. 

Excessive  mental  strain  in  growing  children. 

Hereditary  influence. 

Influence  of  inherited  disease. 

Exanthematous  disease. 

Continued  fevers. 


124  OPERATIVE   DENTISTEY. 

The  local  predisposing  causes  are  : 

Structural  defects  of  the  teeth. 

Traumatic  injuries. 

Irregularities  in  the  arrangement  of  the  teeth. 

Abnormal  oral  secretions. 

These  causes  are  all  more  or  less  important  factors  in  the  predisposition 
and  susceptibility  of  the  teeth  to  caries,  by  reason  of  their  influence  upon 
nutrition  and  vital  resistance,  or  of  their  local  surroundings  or  environment. 

Upon  a  ]3roper  appreciation  of  the  depressing  influences  of  these  con- 
stitutional conditions  upon  the  function  of  nutrition  and  of  vital  resistance 
to  disease,  and  the  effort  to  correct  or  prevent  these  evil  influences  in 
the  future,  will  depend  in  no  small  degree  the  perfection  in  structural 
development  and  the  integrity  of  the  teeth  of  the  generations  yet  unborn. 

CONSTITUTIONAL   PREDISPOSING   CAUSES, 

Environment. — The  term  environment  as  here  used  is  intended  to 
include  all  those  conditions  of  life  which  are  the  results  of  civilization, — 
viz.,  the  xDhysical;  mental,  and  social  conditions,  and  the  food  habit. 

It  has  already  been  stated  that  dental  caries  is  most  prevalent  among 
those  races  and  nations  which  have  attained  to  the  highest  degree  of  civili- 
zation, and  there  can  be  no  doubt  that  a  deterioration  of  the  teeth  is  a  con- 
stant accompaniment  of  the  progress  of  civilization.  Why  civilization 
should  produce  such  effects  is  not  a  very  difficult  question  to  answer.  The 
civilization  of  a  race  or  a  nation  is  a  gradual  process,  and  one  which  affects 
both  the  intellectual  and  physical  development.  The  evolution  of  a  savage 
or  barbarous  race  to  the  plane  of  a  civilized  people  is  the  work  of  centuries. 
The  whole  trend  of  thought  and  of  moral  obligation  and  responsibility  to 
others  has  to  undergo  a  radical  change.  With  these  changes  come  higher 
aspirations,  an  enlargement  of  intellectuality,  and  a  desire  for  more 
knowledge.  Knowledge  is  only  attained  by  study  and  intellectual  pur- 
suits, which  of  necessity  greatly  change  the  habits  and  mode  of  life.  A 
savage,  nomadic  jDCople,  constantly  warring  with  their  neighbors,  begin 
the  process  of  evolution  by  forming  confederations  against  a  greater 
enemy  ;  they  next  intermarry,  and  later,  because  their  common  interests 
demand  it,  settle  in  communities  and  establish  permanent  homes.  As 
their  intellectuality  increases,  the  older  and  wiser  ones  teach  the  younger 
the  value  of  greater  knowledge  than  they  themselves  have  possessed,  as 
this  would  give  them  an  advantage  over  their  enemies.  Finally  some  one 
of  their  number  arises  whom  they  look  upon  as  having  more  wisdom  than 
the  rest,  and  he  becomes  a  leader,  and  perhaps  a  teacher  of  the  tribe. 
Their  language  is  developed,  and  characters  are  invented  by  which  to 
express  the  language  in  writing.  Later,  schools  are  formed,  in  which  the 
more  ambitious  are  taught  in  the  knowledge  possessed  by  the  wise  men.  As 
a  result,  larger  communities  are  formed,  industries  spring  up,  cities  are 
builded,  the  confederated  tribes  become  a  nation,  and  a  ruler  is  chosen. 
Contact  with  other  nations  broadens  the  intellectual  horizon  and  increases 
the  ambition  of  the  people  to  be  equal  to  their  neighbors.  These  ambi- 
tions stimulate  a  desire  for  wealth,  and  riches  result  in  the  introduction 


DENTAL    CARIES,  125 

of  new  and  more  luxurious  habits  of  life  and  greater  devotion  to  intellec- 
tual attainments  and  pursuits,  as  well  as  the  cax^acity  to  enjoy  them. 

The  nation  has  now  reached  the  plane  of  civilization.  With  this  evolu- 
tion has  come  higher  mental  and  nervous  endowments  and  greater  capacity 
to  enjoy  and  to  suffer  ;  but  this  mental  and  nervous  development  has  been 
very  largely  evolved  at  the  expense  of  the  physical  system.  The  powers 
of  physical  endurance  and  of  resistance  to  disease  have  been  greatly 
lowered  by  the  change  in  environment.  War  and  the  chase  have  given 
place  to  the  counting-house  and  the  shop  ;  the  tent  and  the  "dug-out"  are 
now  represented  by  the  cottage  and  the  mansion  ;  the  simple  diet  of  meat 
and  a  few  vegetables,  often  uncooked,  has  been  replaced  by  an  endless 
variety  of  foods,  containing  large  quantities  of  fermentable  substances,  and 
so  i3repared  by  the  culinary  art  that  the  teeth  and  jaws  get  very  little  of 
the  exercise  which  is  so  necessary  to  maintain  them  in  a  healthful  con- 
dition ;  while  the  use  of  food  containing  large  quantities  of  such  ferment- 
able substances  as  starch  and  sugar  present  the  necessary  elements  from 
which  the  acids  are  formed  which  act  upon  the  teeth,  thus  inducing  dental 
caries  and  many  other  diseases  as  sequelae. 

Those  nations  of  the  present  day  which  suffer  most  from  dental  caries 
are  the  Anglo-Saxons  of  America  and  Great  Britain  and  the  great 
European  nations.  The  growth  of  modern  dental  science  and  the  per- 
fection of  the  art  among  these  peoples  has  been  a  work  of  necessity,  and 
one  which  from  its  surgical  aspects  has  kept  pace  in  its  development  with 
the  demands  which  have  been  laid  upon  it. 

But  viewed  from  the  more  important  aspect  of  prophylaxis,  it  has  not 
yet  attained  nor  kept  pace  with  the  ever-increasing  needs  in  this  direction. 
When  one  stops  to  consider  how  wide-spread  and  universal  dental  caries 
has  become,  and  the  increasing  number  of  teeth  that  are  destroyed  by  the 
disease  every  year,  we  are  appalled  by  the  problem,  and  wonder  if  the 
human  race  is  not  destined  to  become  endentulous. 

The  teeth  of  the  present  generation  seem  to  be  inferior  to  those  of  their 
immediate  ancestors,  while  the  children  of  to-day  have,  as  a  rule,  a  greater 
predisposition  to  dental  caries  than  their  parents.  In  other  words,  there 
seems  to  be  a  gradual  deterioration  in  the  structural  development — per- 
fection of  development — of  the  teeth,  and  a  lowering  of  the  resistive 
powers  or  the  vital  energy  of  the  system  against  the  encroachment  of 
disease. 

Perfection  in  the  structural  development  of  the  teeth  of  city-bred  chil- 
dren of  the  middle  and  better  classes  of  society  is  the  exception,  defective 
teeth  the  rule.  Little  children  between  the  ago  of  three  and  six-  years  are 
frequent  sufferers  from  dental  caries,  odontalgia,  and  alveolar  abscess, 
while  very  many  have  defective  first  molars  which  require  attention  as 
soon  as  they  are  erupted. 

This  is  the  age  of  steam  and  electricity,  of  the  lightning  exj)ress  train 
and  the  ocean  greyhound,  of  the  electric  telegraph  and  the  telephone. 

Men,  and  women  too,  have  seemingly  partaken  of  the  energy  and  speed 
of  these  forces.  It  is  an  age  of  rush  and  of  whirl.  Men  and  women  vie 
with  each  other  and  with  their  sex  for  place  and  power.     In  business  and 


126  OPERATIVE    DENTISTRY. 

social  life,  in  educational  matters,  in  their  pleasures  and  vices,  they  go  at 
high-pressure  speed,  and  as  a  result  often  break  down  at  a  period  of  life 
when  under  more  favorable  circumstances  they  would  still  be  in  their 
prime.  These  conditions  are  manifest  everywhere  in  the  civilized  world, 
but  are  most  noticeable  in  the  great  cities,  where  the  intensity  of  the 
struggle  of  the  poor  for  existence  and  of  the  well-to-do  and  the  rich  for 
supremacy  over  their  fellows  in  business,  social  pleasures,  education,  and 
display  are  the  greatest.  Children  born  under  such  circumstances  have 
generally  constitutions  which  are  far  from  equal  to  those  inherited  by 
their  parents,  and  as  a  consequence  they  are  handicapped  in  their  struggle 
for  existence  either  by  the  direct  inheritance  of  disease,  or  of  tendencies 
and  predispositions  to  disease  which  are  the  result  many  times  of  the 
terrible  deprivations  of  poverty,  or  of  overwork  or  over-indulgence  in  the 
luxuries  and  the  pleasures  of  life,  or  of  the  indiscretions  or  the  vices  of 
their  parents  or  earlier  progenitors. 

Such  an  environment  can  only  result  in  enervation,  depression  of 
vital  forces,  malnutrition,  and  defects  in  the  mental,  the  nervous,  and  the 
physical  development. 

Climatic  Influences. — The  influences  of  climate  as  a  predisposing 
cause  of  caries  in  these  days  of  immigration,  colonization,  and  inter- 
national trade  has  come  to  be  an  important  factor,  and  it  should  receive 
that  recognition  from  the  scientific  men  of  the  profession  which  its  impor- 
tance deserves. 

It  has  often  been  remarked,  especially  in  India  and  other  tropical 
climates,  that  the  white  man  was  physically  often  very  profoundly 
affected  by  the  radical  changes  in  the  climate  and  environments.  This  is 
particularly  noticed  in  the  increased  susceptibility  to  disease  and  in  a 
lowered  vitality  or  resistive  power,  so  that  it  has  become  a  recognized  fact 
that  these  people  must,  as  a  rule,  return  to  their  own  country  every  seven 
to  ten  years  in  order  to  recuperate  their  lowered  vitality  and  physical 
stamina.  The  depressing  effects  of  the  climate  are  so  severe  to  some  indi- 
viduals that  a  residence  of  one  or  two  years  under  its  influences  is  sufficient 
to  completely  break  their  health. 

It  can  therefore  be  readily  understood  how  such  depressing  and  ener- 
vating influences  acting  upon  the  general  system  may  lead  to  malnutrition, 
loss  of  nervous  energy,  vitiation  of  the  secretions,  particularly  of  the  oral 
cavity  and  the  alimentary  tract,  and  thus  act  as  predisposing  causes  of 
dental  caries.  That  the  teeth  of  the  average  Briton  who  takes  up  his 
residence  in  India  for  a  period  of  years  decay  more  rapidly  than  they  did 
when  at  home  seems  to  be  the  general  opinion  among  them.  The  same 
opinion  prevails  among  the  American  missionaries  who  have  spent  a 
number  of  years  in  India  and  other  tropical  climates.  These  opinions 
have  been  substantiated  by  the  experiences  of  the  British  troops  in  South 
Africa  and  the  United  States  troops  in  Cuba  and  the  Philippines. 

It  is  a  notable  fact  that  in  this  country,  which  receives  every  year 
large  additions  to  its  population  from  foreign  nations,  principally  from  Eu- 
rope, these  people,  after  a  few  years  of  residence,  often  suffer  greatly  from 
the  ravages  of  dental  caries.     This  the  writer  has  observed  to  be  the  case 


DENTAL   CARIES.  127 

more  particularly  among  the  Irish  and  Scandinavians.  This  tendency 
has  been  ascribed  to  various  causes  ;  some  authorities  have  maintained  that 
it  was  due  as  much  to  a  change  in  the  food  and  social  surroundings  as  to 
climatic  influences. 

Wedl^  in  writing  upon  this  point,  says,  ''If  it  be  true  that  geologic 
and  climatic  conditions,  and  the  means  of  subsistence  which  are  connected 
with  the  same,  have  such  a  preponderating  influence  in  respect  to  the  fre- 
quency of  caries,  then  it  is  impossible  to  explain  the  fact  that  foreigners 
belonging  to  different  races,  who  are  exposed  to  the  same  conditions  as 
the  native  inhabitants,  still  retain  the  typical  structure  of  their  teeth,  as 
well  as  that  of  their  bodies,  and  continue  to  furnish  the  proportion  of 
dental  caries  peculiar  to  their  race.  This  is  found  to  be  the  case  with  the 
isolated  Slavonic  races  of  Austria  and  the  descendants  of  the  Celtic  race  in 
France." 

To  this  remark  Hitchcock  appends  the  following:  "As  geologic,  cli- 
matic, and  social  conditions  exercise  a  predominant  influence  upon  the 
growth  and  development  of  the  various  races,  mentally  as  well  as  physi- 
cally, it  is  evident  that  the  development  of  the  dental  organs  cannot  fail 
to  be  controlled  by  the  same  causes.  In  this  country,  which  is  annually 
receiving  large  numbers  of  foreigners  by  immigration,  the  typical  traces 
of  race  are  usually  effaced  after  the  lapse  of  a  generation  or  two,  the  de- 
scendants possessing  all  the  peculiarities,  and  their  teeth  apparently  being 
as  liable  to  caries  as  the  teeth  of  Americans  generally." 

The  personal  observation  of  the  writer  leads  him  to  the  opinion  that 
the  children  of  immigrants  born  in  this  country  are  not,  as  a  rule,  as 
robust  as  their  parents,  and  that  they  suffer  more  from  dental  diseases. 

Miscegenation. — The  intermarriage  of  individuals  representing  dis- 
tinct nations  and  races  has  come  to  be  a  very  common  occurrence  all  over 
the  civilized  world.  The  railway  trains,  the  steamships,  the  telegrai^h,  and 
the  submarine  cable  have  broken  down  the  barriers  that  once  existed  be- 
tween nations,  and  have  stimulated  the  individual  to  seek  knowledge, 
wealth,  and  home  in  other  climates  than  his  own,  while  the  enlightenment 
which  has  followed  in  the  path  of  these  great  inventions  has  swept  away  in 
large  measure  the  religious  and  race  prejudice  which  befo retime  had  pre- 
vented such  alliances ;  as  a  result,  the  human  family  is  entering  upon  a 
course  which  is  destined  sooner  or  later  to  bring  about  an  amalgamation 
of  those  contiguous  nations  and  races  which  belong  to  the  higher  class  of 
civilization. 

The  crossing  of  distinct  races,  like  the  Anglo-Saxon  and  the  negro,  or 
the  Mongolian  and  the  Malay,  produces  a  progeny  which  is  in  no  way  the 
equal,  physically,  of  either  of  the  races  from  which  they  sprang.  The 
difference  is  principally  noticed  in  a  lowered  state  of  vital  resistance  to 
disease  and  in  the  powers  of  endurance  under  physical  strain. 

Miscegenation  exercises  a  depressing  influence  upon  the  integrity  of 
all  of  the  structures  of  the  body,  tooth-structures  included.  The  crossing 
of  races  and  nations  is  not  generally  productive  of  benefit,  especially  when 
so  widely  separated  as  are  those  of  the  human  species.  ' '  Human  hybrids 
are  notably  deficient  in  physical  completeness  and  vital  power,  nutrition 


128  OPERATIVE    DENTISTRY. 

is  more  or  less  impaired^  and  the  physiologic  x)rocesses  are  weakened,  so 
that  the  entire  economy  is  depressed  and  abnormal."     (Thompson.) 

These  facts  were  so  generally  recognized  in  this  country  during  the  days 
of  slavery,  that  the  slave-dealer  never  made  the  mistake  of  buying  mu- 
lattoes  to  fill  an  order  for  slaves  to  work  in  the  rice-fields  and  sugar  plan- 
tations of  the  far  South,  as  these  people  did  not  possess  the  two  great  pre- 
requisites for  this  kind  of  labor, — viz.,  resistance  to  disease  and  superior 
powers  of  physical  endurance. 

The  mulattoes  on  this  account  were  generally  employed  as  house  ser- 
vants, while  the  blacks  were  in  demand  as  field-hands,  because  they  pos- 
sessed in  a  much  greater  degree  the  necessary  qualifications  for  hard  labor 
and  resistance  to  those  diseases  which  are  so  common  in  the  lowlands  of 
the  South. 

The  half-breeds  of  the  Malay  Archipelago  and  the  Eurasians  of  India 
are  also  examples  of  the  degenerating  physical  effects  of  miscegenation. 

The  effects  of  the  amalgamation  of  nations  is  particularly  seen  in  the 
American  people,  who  are  receiving  a  continuous  stream  of  foreign  and 
heterogeneous  blood  into  their  veins.  ''The  depression  that  has  ensued 
to  the  physique  of  the  people  of  the  United  States  as  a  natural  result  of 
these  intermarriages  may  have  contributed  somewhat  to  the  existing  extra 
defectiveness  of  the  teeth  of  Americans  over  those  of  nations  who  have 
been  less  subject  to  the  effects  of  miscegenation."     (Thompson.) 

Excessive  Mental  Strain  in  the  Growing  Child. — Excessive  men- 
tal strain  coming  at  that  period  in  the  history  of  the  child  when  the  de- 
velopmental changes  are  most  active  and  when  the  nervous  system  is  in  a 
very  exalted  state  and  responds  most  acutely  to  all  forms  of  stimulation 
and  depression,  is  often  productive  of  conditions  which  lower  the  general 
tone  of  the  system  and  disturb  the  functions  of  digestion,  assimilation, 
and  nutrition,  and  thus  lay  the  foundation  for  a  train  of  physical  ailments 
from  which  the  child  may  never  fully  recover,  while  the  nerve-centres 
may  be  so  impressed  as  to  produce  nervous  prostration,  chorea,  epilepsy, 
paralysis,  and  kindred  complaints.  This  lowering  of  the  general  tone  of 
the  system,  the  disturbance  to  the  nutritive  functions,  and  the  nervous 
phenomena  which  may  develop  as  a  result  of  mental  strain  in  growing 
children  play  an  important  part  in  the  greater  predisposition  to  dental 
caries  so  generally  noticed  at  this  period  of  life,  by  producing  devel- 
opmental defects  in  the  structures  of  the  teeth,  vitiated  oral  secretions,  and 
rendering  the  child  less  able  to  successfully  cope  with  disease-producing 
germs. 

The  tendency  of  the  age  is  to  force  children  in  their  school  work  to  the 
limit  of  what  they  are  mentally  and  physically  able  to  endure.  This 
system  ai)plied  to  ambitious  children  often  operates  to  their  disadvantage, 
as  they  are  inclined  to  go  beyond  their  strength,  and  sooner  or  later  the 
health  is  undermined,  the  teeth  break  down  from  caries,  and,  unless  the 
strain  is  removed  and  the  child  given  a  complete  rest,  change  of  air,  and 
surroundings,  physical  and  nervous  prostration  are  the  result. 

The  author  has  often  found  it  necessary  to  advise  parents  and  guar- 
dians to  remove  a  child  from  school  to  save  the  health  from  being  wrecked. 


DENTAL    CARIES, 


129 


In  many  of  these  cases  the  rapid  decay  of  the  teeth  was  the  prominent 
symptom  which  attracted  his  attention  and  led  to  an  investigation  of  the 
general  health  and  surronndiugs  of  the  child. 

Hereditary  Influence. — Inherited  tendencies  or  x^i^edisposition  to 
caries  of  the  teeth  is  often  well  marked  in  certain  families.  This  predis- 
position is  donbtless  established  by  the  transmission  of  some  abnormality 
in  the  form  of  the  teeth  or  by  a  direct  structural  malformation  of  the 
enamel  or  the  dentin.  The  children  of  parents  whose  teeth  have  been  lost 
early  in  life  from  dental  caries  are  unquestionably  very  prone  to  be  affected 
with  like  conditions.  So  well  has  this  hereditary  influence  been  estab- 
lished that  it  is  not  an  infrequent  exj)erience  to  find  special  teeth  in  mem- 
bers of  the  same  family  attacked  by  the  disease,  and  at  relatively  the 
same  period  of  life. 

Influence  of  Inherited  Disease. — Hereditary  tendencies  and  predis- 
positions to  certain  diseases  like  tuberculosis,  rheumatism,  gout,  various 
nervous  affections,  and  insanity  are  often  well  marked  ;  but  syphilis  is  the 
only  disease  that  has  been  positively  demonstrated  to  be  directly  trans- 
mitted from  parent  to  child. 

The  syphilitic  virus  predisposes  to  dental  caries  through  its  depressing 
influence  upon  nutrition  and  its  tendency  to  attack  epithelial  structures, 
thus  producing  atrophy  of  the  ameloblasts  in  those  teeth  in  which  the 
process  of  calcification  is  about  to  begin,  and  forming  faults  or  imperfec- 
tions in  the  enamel  which  later  become  the  starting-point  of  caries. 

If  the  student  will  refer  to  the  chart  showing  the  progress  of  calcifica- 
tion of  the  permanent  teeth  (Fig.  225,  page  78),  he  will  notice  that  the  only 
teeth  in  which  calcification  is  progressing  up  to  the  end  of  the  second  year 
of  existence  are  the  first  molars  and  the  central  and  lateral  incisors,  and 
these  are  the  teeth  which  are  always  the  most  profoundly  affected  by  the 
action  of  the  virus  in  inherited  syphilis.  This  will  be  readily  understood 
when  it  is  remembered  that  the  most  active  stage  of  the  disease  in  these 
unfortunate  children  is  during  the  first 
and  second  years  after  birth.  When  this 
stage  is  prolonged  to  the  third  year  the 
cuspids  are  also  affected. 

Jonathan  Hutchinson  first  called  at- 
tention to  the  peculiar  effects  of  inherited 
syphilis  upon  the  permanent  teeth,  and 
offered  the  only  adequate  explanation  of 
their  malformation, — viz.,  interrupted  nu- 
trition. These  malformations  consist  of 
an  atrophied  condition  or  lack  of  develop- 
ment of  the  enamel  upon  the  morsal  surfaces  of  the  first  molars  and  the 
morsal  edge  of  the  incisors,  with  a  notched  condition  of  the  morsal  edge 
of  the  central  incisors,  semilunar  in  outline  (Fig.  269).  The  incisors,  both 
upper  and  lower,  have  often  a  stunted  appearance,  and  are  narrower  at  the 
morsal  edge  than  at  the  cervix.  The  upper  lateral  incisors  are  sometimes 
very  much  dwarfed,  resembling  pegs  or  inverted  cones.  Hutchinson  re- 
garded the  semilunar  notch  in  the  central  'incisor  teeth  as  diagnostic  of 

9 


Fig.  269. 


Syphilitic  teetli.    (After  Hutchinson.) 


130  OPERATIVE    DENTISTRY. 

inherited  syphilis.  Tliis  view  has,  however,  been  called  in  question,  as 
the  same  condition  has  been  noted  in  children  to  whom  mercury  had  been 
administered  in  infancy  until  the  system  was  profoundly  impressed,  but 
who  had  not  inherited  syphilis.  And  inasmuch  as  mercury  is  usually 
administered  in  inherited  syphilis,  the  question  has  been  raised  as  to 
whether  the  peculiar  malformation  is  due  to  the  effects  of  the  virus  or  to 
the  drug.  On  the  other  hand,  the  malformation  is  common  in  children 
with  inherited  syphilis  who  have  received  no  treatment  of  any  kind.  It 
therefore  seems  probable  that  both  the  virus  and  the  drug,  by  their  de- 
pressing effects  upon  the  functions  of  nutrition,  are  capable  of  producing 
these  peculiar  malformations. 

Teeth  of  this  character  are  very  prone  to  caries  at  those  points  where 
the  enamel  is  defective  or  entirely  lacking,  and  yet  certain  cases  will  resist 
the  inroads  of  the  disease  for  many  years. 

Exanthematous  Diseases  and  the  Continued  Fevers. — The  exan- 
thems  and  the  continued  fevers  occurring  at  the  time  of  dental  development 
retard  or  arrest  this  process  for  a  shorter  or  longer  period,  according  to 
the  severity  of  the  disease  and  the  recuperative  powers  of  the  child.  This 
interference  with  nutrition  is  indelibly  impressed  upon  the  developing 
teeth  by  pits  and  grooves  which  encircle  the  crowns  of  the  teeth  at  that 
I)articular  part  of  the  enamel  which  was  undergoing  calcification  at  the 
time,  or  the  enamel  may  be  imperfectly  developed  at  the  morsal  edge  of 
the  incisors  and  the  cuspids,  or  at  the  cusps  of  the  molars.  Sometimes 
the  enamel  is  entirely  absent  over  a  considerable  portion  of  the  crown. 

The  teeth  which  are  most  liable  to  be  affected  in  this  manner  are  the 
first  permanent  molars,  the  incisors,  and  the  cuspids. 

Various  other  diseases,  like  diphtheria,  convulsions,  and  the  gastric 
and  intestinal  affections,  so  common  among  children  during  the  period  of 
dental  development,  may  produce  like  developmental  defects. 

Cases  of  this  character  are  of  frequent  occurrence.  One  of  the  most 
marked  instances  of  this  kind  which  ever  came  under  the  observation  of 
the  writer  was  a  little  boy  ten  years  old,  who  was  at  this  age  in  apparently 
good  health,  but  rather  small  and  slender  for  one  of  his  years,  and  of 
strumous  diathesis  and  nervous  temperament.  His  teeth  up  to  this  age 
had  erupted  at  the  normal  period.  The  deciduous  teeth  had  all  been  well 
formed,  but  very  frail,  and  nearly  all  of  them  had  been  treated  for  caries. 
The  permanent  teeth  which  had  so  far  erupted  were  the  sux)erior  and  in- 
ferior first  molars,  and  the  central  and  lateral  incisors  and  first  bicuspids. 
All  of  these  teeth  except  the  bicuspids  were  devoid  of  enamel  over  the 
whole  extent  of  the  crowns,  except  a  narrow  band  at  the  cervical  margin. 
The  denuded  surfaces  were  quite  sensitive  to  the  touch  of  instruments,  or 
the  action  of  acids,  sweets,  or  thermal  changes.  The  bicuspids  were  nor- 
mally developed.  The  child  was  born  of  a  highly  cultured  but  extremely 
nervous  mother,  with  tubercular  tendencies.  For  the  first  three  years  of 
his  life  the  child  was  continually  ill,  suffering  from  gastric  troubles  and 
convulsions  whenever  there  was  any  slight  irritation  to  the  nervous 
system.  If  his  milk  were  ever  so  little  changed  by  lactic  acid  fermentation, 
or  he  were  ever  so  slightly  overfed,  convulsions  usually  followed,  and  it  was 


DENTAL   CARIES.  131 

only  by  the  most  careful  nursing  that  he  was  carried  through  the  critical 
period  of  first  dentition. 

There  is  also  a  rai)id  increase  in  the  progress  of  caries,  as  well  as  a 
greater  predisposition  or  susceptibility  to  the  disease  in  pregnancy,  tuber- 
culosis, typhoid  fever,  diabetes,  and  other  wasting  diseases.  Similar  con- 
ditions jprevail  in  ansemic  and  leuksemic  states.  It  is  a  noticeable  fact 
that  in  young  girls  who  are  suffering  from  chlorosis  the  teeth  often  exhibit 
an  increased  tendency  to  caries  and  exceptionally  rapid  progress  of  the 
disease. 

Certain  occupations  have  been  thought  by  some  authorities  to  predis- 
pose to  caries ;  for  instance,  millers,  bakers,  and  candy-makers  show  an 
especial  liability  to  caries,  as  do  also  workers  in  alkali,  phosphorus, 
arsenic,  chlorine,  and  sulphuric  acid  manufactories. 

LOCAL   PREDISPOSING    CAUSES. 

Structural  Defects  of  the  Teeth. — Structural  defects  in  the  enamel, 
the  result  of  constitutional  conditions  which  have  impaired  nutrition  and 
thus  prevented  the  proper  development  of  this  tissue,  are  a  most  impor- 
tant factor  in  predisposing  the  teeth  to  caries.  The  most  observable  of 
these  defects  have  just  been  referred  to, — viz.,  pits  or  honey-combed  con- 
ditions, grooves,  and  the  absence  of  enamel  upon  certain  portions  of  the 
crowns.  The  less  noticeable  but  more  important  defects  are  those  which 
may  be  found  in  almost  all  teeth,  even  of  the  most  perfect  development, — 
viz.,  the  sulci,  fissures,  and  pits  formed  by  the  union  of  the  developmental 
lobes.  Fig.  270  shows  such  a  condition.  At  these  points  the  enamel-rods 
many  times  seem  to  have  been  imperfectly  cemented  together,  or  the  sulci 
and  fissures  are  so  deep  as  to  give  ready  lodgement  for  food  debris.  These 
conditions  invite  the  establishment  of  caries  by  making  it  possible  for  the 
micro-organisms  of  the  disease  to  find  a  lodgement  where,  undisturbed, 
they  may  propagate  and  flourish. 

Many  of  the  enamel  defects  are  so  infinitesimal  in  size  as  to  require  the 
aid  of  high-power  objectives  for  their  discovery,  and  yet  they  are  sufii- 
cieutly  large  to  give  lodgement  to  masses  of  micro-organisms. 

Structural  defects  of  the  enamel  which  leave  the  dentin  exposed  to  the 
action  of  the  micro-organisms  favor  rapid  disintegration  of  this  tissue ; 
but  if  the  exposed  surface  of  the  dentin  is  of  such  shape  or  in  such  a  loca- 
tion that  the  lodgement  of  bacteria  can  be  prevented,  caries  will  be  no 
more  likely  to  occur  at  these  points  than  u]3on  the  enamel  itself. 

The  rapidity  with  which  caries  progresses  in  the  dentin  will  depend 
in  large  measure  upon  the  character  of  the  structure  of  this  tissue.  Den- 
tin in  which  the  interglobular  spaces  are  numerous  does  not  seem  to  possess 
the  same  degree  of  resistance  to  the  invasion  of  the  micro-organisms  of 
decay  as  those  teeth  which  are  more  perfectly  organized. 

Black  has  shown  very  conclusively  that  the  chemical  constituents  of 
the  teeth  do  not  exhibit  a  sufficient  variation  to  account  for  the  differences 
observed  in  the  rapidity  with  which  structural  disintegration  takes  place 
in  caries,  and  that  the  variations  in  the  amount  of  lime-salts  in  the  dentin 
are  not  enough  to  exiDlain  their  variation  in  hardness. 


132  OPERATIVE   DENTISTRY. 

It  must  be  conceded^  however,  tliat  alterations  in  the  structural  organi- 
zation and  chemical  constituents  of  the  dentin  modify  to  a  greater  or  less 
extent  the  progress  of  the  disease.  ^'The  forces  of  attack  being  equal, 
a  poorly  organized  and  badly  formed  tooth  will  succumb  sooner  than  one 
perfectly  formed  and  of  completely  organized  tissues  ;  this  law  is  constant 
in  all  biology."     (Burchard.) 

Another  structural  defect  which  predisposes  to  caries  is  the  deviations 
from  the  normal  in  the  external  forms  of  the  teeth.  Teeth  of  the  most 
perfect  form  are  broader  at  their  morsal  surfaces  than  at  the  cervix ;  in 
other  words,  are  bell-crowned.  This  form  of  tooth  in  a  normal  dental 
arch  permits  approximal  contact  with  each  of  its  neighbors  at  one  point 
only, — viz.,  near  the  morsal  margin  of  the  approximal  surface  of  the 
bicuspids  and  molars  and  the  morsal  edge  of  the  incisors  and  cuspids,  thus 
separating  each  tooth  from  its  fellow  by  V-shaped  interspaces,  which  are 
generally  kept  clean  by  the  passage  through  them  of  the  fluids  of  the 
mouth.  If,  on  the  other  hand,  the  labio-lingual  diameter  of  the  crowns 
is  much  greater  than  the  mesio-distal,  and  the  approximal  surfaces  are 
flattened,  these  surfaces  of  the  teeth  lie  closer  together,  nearly  if  not  quite 
obliterating  the  proximate  interspaces,  thus  making  it  difficult  or  impos- 
sible to  keep  them  free  from  alimentary  debris,  and  favoring  the  lodgement 
and  growth  of  the  bacteria  of  fermentation. 

Traumatic  Injuries. — Defects  in  the  enamel  caused  by  traumatic  in- 
juries are  not  nearly  so  common  as  the  developmental  defects,  and  are 
not,  as  a  rule,  so  liable  to  become  the  starting-point  of  caries.  Injuries 
which  fracture  the  enamel,  leaving  the  dentin  exposed,  if  occurring  at 
points  which  are  subject  to  the  friction  of  mastication,  or  of  such  shape 
as  to  be  self-cleansing,  rarely  develop  caries  ]  but  when  the  reverse  is  the 
case,  caries  will  often  be  established  in  a  very  short  time.  Injuries  which 
cause  crushing  or  splitting  of  the  enamel  without  dislocation  of  the  frag- 
ments are  much  more  liable  to  become  the  starting-point  of  caries  than 
those  fractures  which  cause  loss  of  tissue,  from  the  fact  that  they  offer 
much  more  favorable  conditions  for  the  entrance  of  bacteria  and  their 
undisturbed  propagation.  Fig.  271  shows  caries  following  a  crack  in  the 
enamel. 

Irregularities  in  the  Arrangement  of  the  Teeth. — Teeth  which 
are  irregular  in  their  arrangement  in  the  arch,  no  matter  how  perfect  they 
may  be  in  structure  and  form,  have  a  much  greater  predisposition  to 
caries  than  those  which  have  a  normal  arrangement. 

Nature  in  constructing  the  typical  dental  organs  of  man  and  arranging 
them  in  the  perfect  arch,  placed  them  in  the  best  possible  condition  to 
withstand  the  action  of  those  destructive  agencies  which  continually  sur- 
round them.  Any  deviation  from  this  perfection  of  form  and  arrange- 
ment must,  therefore,  necessarily  predispose  the  teeth  to  be  acted  upon 
by  these  agencies,  while  the  degree  of  predisposition  will  be  largely  con- 
trolled by  the  character  and  degree  of  the  irregularity  in  form  and  po- 
sition. 

By  mal-arrangement  of  the  teeth  certain  of  their  surfaces  are  rendered 
very  difficult  or  well-nigh  imiDOSsible  to  cleanse  by  natural  or  artificial 


Dental  fibres, 
penetrating 
the  enamel 


Caries  of 
n''%  enamel  in 
fissure 


Fig.  270.— Section  of  human  molar,  showing  caries  of  enamel  following  a  fissure.    X  95. 


Dentinal  tubuli  ,,,,,„,,  b,,,,. 
entering  the  Wf '!''»«« 
■n^r.^    el  I'j  ifl 

Hi 


enamel 


Dentin 


iMij 

Fit.   J71  — Caries  followin 


Caiies  follow- 
ing crack  in 
enamel 


Enamel 


DENTAL    CARIES.  133 

means,  and  thus  the  active  agencies  of  caries  are  furnished  with  the  best 
possible  conditions  for  the  establishment  of  their  destructive  work. 

Injuries,  extractions,  or  the  necessary  loss  of  a  tooth  often  cause  mal- 
position of  adjoining  teeth,  and  render  the  approximal  surfaces  more  diffi- 
cult to  be  cleansed  by  the  natural  agencies  of  the  mouth,  and  by  that  much 
establish  a  greater  predisposition  to  caries.  The  injudicious  use  of  the 
file  is  also  a  predisposing  cause  of  caries,  and  secondary  caries  is  often 
invited  by  failure  to  restore  the  normal  contour  of  the  teeth  when  inserting 
approximal  fillings.  Broad  contacts  upon  the  approximating  surfaces  of 
the  teeth  are  grave  deviations  from  the  normal  condition  of  a  perfect 
dental  arch,  and  should  never  be  allowed  to  obtain  as  the  result  of  opera- 
tion, as  all  such  conditions  invite  a  recurrence  of  the  disease. 

Abnormal  Oral  Secretions. — ITormal  mixed  saliva  is  generally  alka- 
line in  its  reaction.  Parotid  saliva  is  faintly  alkaline,  while  the  secretion 
from  the  submaxillary  glands  is  more  strongly  alkaline,  as  is  that  from  the 
sublingual  glands.  The  secretion  from  the  parotid  is  a  clear,  watery  fluid, 
while  that  from  the  submaxillary  glands,  though  a  limpid  liquid,  is  quite 
viscous,  a  quality  which  under  the  influences  of  cold  gives  it  an  almost 
gelatinous  consistence. 

The  secretion  from  the  sublinguals  is  a  limpid  viscid  fluid,  but  rich  in 
ptyalin,  which  gives  it  a  ropy  consistency.  The  secretion  from  the  buccal 
mucous  glands  is  also  a  viscid  fluid,  rich  in  mucin,  and  has  an  acid 
reaction. 

Changes  in  the  character  of  these  secretions  often  take  place  as  a  result 
of  certain  morbid  conditions  of  the  mouth  or  of  the  general  system. 

The  morbid  oral  conditions  which  may  induce  alterations  in  the 
character  of  the  saliva  are  stomatitis  in  its  various  forms,  gingivitis, 
tonsillitis,  pharyngitis,  and  diphtheria.  These  inflammatory  conditions 
greatly  augment  the  secretion  of  buccal  mucus,  and  as  a  consequence 
there  is  a  marked  increase  in  the  acidity  of  the  oral  fluids.  This  is  made 
evident  by  the  use  of  litmus  paper,  and  ^'by  the  solution  and  consequent 
disappearance  at  such  times  of  deposits  of  tartar."     (Magitot.) 

The  morbid  conditions  of  the  general  system  which  may  induce  altera- 
tions in  the  character  of  the  oral  secretions  are  certain  acute  and  chronic 
diseases. 

Among  the  general  acute  affections  which  may  produce  these  eifects  are 
the  eruptive  fevers,  typhoid  and  malarial  fevers,  pneumonia,  bronchitis, 
pleurisy,  gastritis,  enteritis,  and  the  constitutional  effects  of  such  drugs 
as  mercury,  potassium  iodide,  etc. 

In  all  of  these  conditions  it  has  been  observed  by  various  writers, 
from  Donne  (who  called  attention  to  these  facts  in  1835)  to  the  present 
time,  that  the  oral  secretions  presented  an  acid  reaction,  and  that  accom- 
panying this  condition  there  was  hypersensitiveness  of  the  teeth,  with  an 
increased  predisposition  to  caries. 

The  general  chronic  affections  in  which  these  changes  are  most  often 
noticed  in  the  oral  secretions  are  rheumatism,  gout,  dyspepsia,  chronic 
enteritis,  dysentery,  gastralgia,  and  pulmonary  tuberculosis.  "Their 
effect  is  to  exaggerate  the  production  of  ptyalin,  the  agent  of  viscidity, 


134  OPERATIVE   DENTISTRY. 

and  to  excite  a  hypersecretion  of  mucin,  two  phenomena  caused  either  by 
the  direct  influence  of  intestinal  alteration  or  by  reflex  action  of  the  gen- 
eral condition  upon  the  conditions  of  the  mouth."     (Magitot.) 

Like  conditions  are  frequently  observable  in  certain  physiologic  states, 
as  in  i)regnancy  and  lactation.  Acid  reaction  of  the  saliva  and  hyper- 
sensitiveness  of  the  teeth,  with  an  increased  predisposition  to  caries,  is  so 
common  among  women  during  these  states  that  the  tendency  among  them 
at  these  times  to  lose  their  teeth  has  been  crystallized  into  the  terse  adage, 
"  for  every  child  a  tooth." 

In  mouths  which  show  an  acid  reaction  of  the  saliva  it  is  common  to 
find  an  increased  quantity  of  ptyalin  and  mucin,  which  give  an  albuminous, 
ropy  appearance  to  the  secretion. 

These  substances,  being  capable  of  coagulation,  give  a  tenacious  char- 
acter to  the  saliva  and  cause  it  to  cling  to  the  surfaces  of  the  teeth,  thus 
forming  a  convenient  medium  for  the  growth  and  destructive  action  of  the 
bacteria  of  decay  and  the  retention  and  fermentation  of  food  debris. 


CHAPTEE    YIIL 

DENTAL   CARIES    (CONTINUED). 

The  agents  whicli  are  immediately  responsible  for  the  production  and 
maintenance  of  a  disease  are  termed  its  direct,  exciting,  or  active  causes. 
These  causes  are  often  obscure,  and  many  times  entirely  hidden  from 
observation. 

Dental  caries  was  thought  by  many  of  the  older  writers  to  be  analo- 
gous to  caries  of  bone,  but  this  cannot  be  the  case,  for  the  physical  phe- 
nomena of  disintegration  of  these  tissues  are  so  very  different.  Caries  of 
the  bone  is  an  inflammatory  molecular  disintegration  of  tissue,  a  retrograde 
metamorphosis.  The  organic  and  inorganic  substances  or  elements  are 
dissolved  or  break  down  together,  and  are  carried  away  in  the  sanies  or 
pus  which  is  formed  as  a  result  of  the  inflammation. 

In  caries  of  dental  tissue  there  are  no  inflammatory  symptoms  except 
that  of  increased  sensibility.  Modern  research  has  demonstrated  that 
caries  is  caused  by  zymogenic  organisms.  The  inorganic  elements  of  the 
tissue  are  first  removed  by  chemical  solution  produced  by  the  acid-form- 
ing bacteria  of  the  mouth,  while  the  organic  material  or  basis  substance 
becomes  gangrenous  and  is  afterwards  dissolved  by  the  liquefying  action 
of  the  sapro]3hytio  micro-organisms  and  is  washed  away. 

For  more  than  two  thousand  three  hundred  years  dental  caries  has 
formed  an  interesting  subject  for  medical  writers  and  theorists. 

The  etiology  of  the  disease  has  always  furnished  a  most  interesting 
field  for  original  investigation  and  research,  while  the  peculiarities  of 
the  physical  i)henomena  presented  by  the  disease  and  the  obscurity  of 
the  causes  which  produced  them  have  led  to  many  and  divers  opinions. 
As  a  result,  several  theories  have  from  time  to  time  been  advanced  to 
explain  the  phenomena  which  are  manifest  in  the  dissolution  of  these 
tissues. 

The  ancient  physicians  and  dentists  who  made  any  attempt  to  inquire 
into  the  causes  of  the  affection  seemingly  contented  themselves  with  offer- 
ing hypotheses  more  or  less  ingenious,  but  based  in  part  upon  experience 
and  clinical  observation,  to  account  for  the  physical  phenomena  of  the 
disease.  No  real  investigation,  however,  that  could  be  called  scientific 
was  at  all  possible  until  the  invention  of  the  microscope  opened  the  way 
for  the  study  of  the  histologic  structure  of  the  dental  tissues,  both  normal 
and  pathologic,  and  the  minute  bacterial  forms  which  we  now  know  to  be 
the  cause  of  so  many  diseases. 

History. — It  will  be  interesting  to  the  student  to  briefly  review  the 
following  theories  and  trace  the  evolutionary  steps  by  which  the  direct 
causes  of  the  disease  were  finally  discovered  : 

135 


136  OPERATIVE    DENTISTRY. 

1.  The  Humoral  Theory. 

2.  The  Vital  or.  Inflammatory  Theory. 

3.  The  Worm  Theory. 

4.  The  Putrefaction  Theory. 

5.  The  Chemical  Theory. 

6.  The  Electro-Chemical  Theory, 

7.  The  Germ  Theory. 

The  Humoral  Theory  of  Caries. — Hippocrates  (B.C.  456)  and  his 
pupils  were  humoral  pathologists.  Hippocrates  taught  that  the  body  con- 
tained four  fluid  humors, — viz.,  blood,  phlegm,  yellow  bile,  and  black 
bile  ]  that  a  proper  or  due  proportion  of  each  of  these  humors  constituted 
health,  while  a  disturbance  of  the  proportions  resulted  in  illness.  He 
ascribed  all  diseases  to  this  cause ;  hence  he  and  his  followers  ascribed 
dental  caries  to  a  bad  condition  of  the  humors, — viz.,  to  the  stagnation  of 
depraved  juices  in  the  teeth. 

This  view  was  generally  maintained  by  physicians  for  more  than  a 
thousand  years,  and  is  still  prevalent  in  the  traditions  of  the  common 
people. 

Bourdet  (1757)  still  maintained  the  humoral  theory  of  Hippocrates, 
while  most  of  his  contemporaries  accepted  the  vital  theory.  He  claimed 
that  when  the  fluids  contained  in  the  vessels  of  the  tooth  are  too  thick 
they  coagulate,  and  since  they  are  confined,  putrefy  and  act  directly  upon 
the  structures  of  the  tooth,  producing  caries.  He  also  called  attention  to 
the  fact  that  when  a  tooth  decays,  its  fellow  upon  the  opposite  side  of  the 
jaw  is  sooner  or  later  similarly  and  symmetrically  affected,  and  exx)lains 
this  predisposition  by  the  fact  that  as  corresponding  teeth  are  usually  cal- 
cified at  the  same  x^eriod  and  pursue  the  same  order  of  development,  so 
the  same  morbid  j)rocesses  are  commonly  manifested  in  the  same  locations 
of  corresi^onding  teeth. 

The  Vital  or  Inflammatory  Theory  of  Caries. — Galen  (a.d.  131) 
looked  upon  dental  decay  as  being  caused  by  a  disturbance  in  the  func- 
tions of  nutrition.  He  said,  "The  lack  of  nutrition  makes  the  teeth  weak, 
thin,  and  brittle,  while  an  excess  of  nutrition  excites  an  inflammation  very 
similar  to  that  of  the  soft  parts." 

Ambroise  Pare  (1579),  the  noted  French  surgeon,  held  to  the  theory  of 
the  inflammatory  nature  of  dental  caries.  He  says,  in  discussing  the  sub- 
ject of  toothache,  "These  organs,  after  the  manner  of  other  bones,  suffer 
from  inflammation,  quickly  suppurate,  and  become  rotten." 

Fauchard  believed  with  Galen  that  caries  was  caused  by  vital  or  in- 
flammatory action,  and  described  seven  forms  of  the  disease, — viz.,  scor- 
butic, variolous,  scrofulous,  moist  or  putrid,  dry,  superficial,  and  deep  ;  the 
latter  form  giving  rise  to  severe  pain.  He  assumed  that  there  must  be  two 
causes  for  caries,  as  for  all  other  diseases  of  the  teeth,  one  of  internal  origin, 
producing  internal  caries;  the  other  external  in  origin,  and  producing 
external  caries. 

The  internal  causes,  he  stated,  were  referable  "generally  to  the  quantity 
and  quality  of  faulty,  acrid,  or  corrosive  lymph,  which  acts  upon  their 
roots,  attacking  their  external  and  internal  surfaces."     The  latter  doubt- 


DENTAL    CARIES.  137 

less  referring  to  the  root-canal  and  i)ulp- chamber.  This  variety,  he 
stated,  was  difficult  to  recognize,  from  the  fact  that  it  is  concealed  from 
view  by  the  gums  and  the  alveolus.  The  external  causes  he  does  not  ex- 
plain, but  said  these  attack  the  outer  portions  of  the  tooth, — viz.,  the 
enamel,  occasionally  the  neck,  and  the  roots. 

The  prevailing  opinion  of  the  medical  men  of  this  period  was  that 
caries  of  the  teeth  was  due  to  inflammation,  or,  in  other  words,  to  vital 
action;  that  it  was  a  true  disease  of  dentin,  the  term  "Odontitis"  being 
given  to  it.  Upon  this  supposition  the  researches  of  Fauchard,  Bourdet, 
Jourdain,  Hunter,  Fox,  Bell,  Cuvier,  Duval,  Linderer,  Meckel,  etc.,  were 
conducted. 

This  theory  was  revived  by  Newmann  (1862),  while  Hertz  and  Abbott 
later  attempted  to  confirm  it,  but  with  indifferent  success. 

Jourdain  (1766)  believed  with  Fauchard  in  the  exclusively  vital  or 
organic  nature  of  the  affection,  which  was  at  times  inflammatory. 

Hunter  (1778)  maintained  that  the  disease  was  a  vital  process,  characterized 
by  inflammation  and  gangrene,  and  somewhat  analogous  to  caries  of  bone. 
He  said,  '^It  does  not  arise  from  internal  injury  or  from  menstrua,  which 
have  the  power  of  dissolving  part  of  a  tooth,  but  we  may  reasonably  sup- 
pose that  it  is  a  disease  arising  originally  within  the  tooth  itself." 

He  does  not,  however,  seem  satisfied  with  the  idea  of  the  analogy  be- 
tween the  carious  i^rocess  as  observed  in  bone-tissue  and  in  tooth -substance, 
as  it  does  not  satisfactorily  explain  the  phenomena  of  gradual  decomxDO- 
sition  and  loss  of  tissue  with  the  formation  of  cavities.  Upon  this  point 
he  says,  "The  most  common  disease  to  which  the  teeth  are  exposed  is 
such  a  decay  as  would  appear  to  deserve  the  name  of  mortification.  But 
there  is  something  more  ]  for  the  simjDle  death  of  the  part  would  produce 
but  little  effect,  as  we  find  that  the  teeth  are  not  subject  to  x)utrefaction 
after  death,  and  therefore  I  am  apt  to  suspect  that  during  life  there  is 
some  operation  going  on  that  produces  a  change  in  the  diseased  i)art.  It 
almost  always  begins  externally  {external  caries)  in  the  small  part  of  the 
body  of  the  tooth,  and  commonly  appears  first  as  an  opaque  white  spot. 
This  is  owing  to  the  enamel  losing  its  regular  crystalline  texture  and  being 
reduced  to  a  state  of  powder  from  the  attraction  of  cohesion  being  de- 
stroyed, which  j)roduces  similar  effects  to  those  of  powdered  crystal. 
When  this  has  crumbled  away  the  bony  part  of  the  tooth  is  exposed,  and 
when  the  disease  has  attacked  this  part  it  generally  appears  as  a  brown 
speck." 

He  also  claimed  that  occasionally  the  disease  originated  in  the  dentin 
(internal  caries),  and  that  in  this  case  the  tooth  assumed  a  shining  black- 
ness from  the  dark  color  being  seen  through  the  remaining  external  shell 
of  the  tooth,  which  U]3on  opening  is  found  leading  to  the  pulp-canal. 

Fox  (1806)  expresses  the  belief  that  "the  diseases  to  which  the  teeth 
are  subject  have  their  origin  in  inflammation."  In  writing  of  the  proxi- 
mate or  direct  cause  of  caries,  he  considered  it  to  be  "an  inflammation 
in  the  bone  of  the  crown  of  the  tooth,  which  on  account  of  its  peculiar 
structure  terminates  in  mortification."  This  process,  he  believed,  was 
established  through  inflammation  of  the  dental  pulp  and  lining  membrane 


138  OPERATIVE    DENTISTRY. 

of  the  pulp-clianiber  (membrana  eboris).  He  evidently  considered  tlie 
pulp-membrane  as  analogous  to  the  periosteum,  and  confounded  necrosis 
with  caries  ;  for  he  stated  that  if  the  inflammation  was  severe  in  the  pulp- 
membrane,  nutrition  would  be  arrested  in  circumscribed  areas,  as  in  peri- 
ostitis, thus  causing  death  of  portions  of  the  dentin,  which  would  after- 
wards decomj)ose  and  form  cavities  of  decay. 

Bell  (1831)  maintained  that  dental  caries  was  a  species  of  gangrene, 
and  that  ''the  true  proximate  cause  of  dental  gangrene  was  inflammation." 
He  did  not  believe  that  caries  was  ever  caused  by  eodernal  agencies  which 
acted  upon  the  enamel,  but  was  due  to  internal  causes  which  produced  death 
of  portions  of  the  dentin.  He  defines  dental  gangrene  as  '^  mortification  of 
any  part  of  a  tooth,  producing  gradual  decomposition  of  its  substance." 
Further  he  says,  "The  situation  in  which  gangrene  (caries)  invariably 
makes  its  first  appearance  is  immediately  under  the  enamel,  upon  the  sur- 
face of  the  bone  (dentin)."  This,  he  thought,  was  explained  by  the  struc- 
ture of  the  teeth  and  the  nature  of  the  disease.  "As  the  vessels  and 
nerves  which  supply  the  bone  of  the  teeth  are  principally  derived  from 
the  internal  membrane  (pulp),  -it  is  natural  to  conclude  that  in  so  dense  a 
structure  the  organization  would  be  less  perfect  in  those  parts  which  are 
farthest  removed  from  its  source,  and  that  in  the  same  portion  they  would 
be  less  capable  of  resisting  the  progress  of  mortification."  With  regard  to 
the  progressive  character  of  the  disease,  he  thought  this  could  only  be  ex- 
plained by  following  the  same  reasoning.  "When  a  portion  of  any  of 
the  other  bones  loses  its  vitality  it  acts  as  an  extraneous  body,  producing 
irritation  in  the  surrounding  parts,  and  a  process  of  absorption  is  set  up  in  a 
line  of  living  bone  in  contact  with  it  in  order  to  effect  its  separation.  A 
similar  effort  appears  to  me  to  be  made  in  gangrene  of  the  teeth,  but  with 
a  very  different  result,  in  accordance  with  the  difference  in  the  structure 
of  the  two  seats  of  the  disease.  When  a  portion  of  the  tooth  is  killed  by 
inflammation  it  excites,  as  in  the  other  case,  an  increased  action  in  the 
vessels  of  the  surrounding  portion  of  bone  ;  but  that  very  -action,  which  in 
such  bones  as  possess  greater  vital  power  becomes  remedial  by  promoting 
the  removal  of  the  cause  of  irritation,  produces  in  the  present  case  the 
continued  extension  of  the  disease  ;  for  the  irritation  thus  excited,  instead 
of  effecting  the  removal  of  the  part  by  absorption,  as  in  other  necrosed 
bones,  at  once  destroys  its  vitality  and  renders  it  only  an  additional  por- 
tion of  dead  matter  to  that  which  had  already  existed.  This,  in  its  turn, 
becomes  an  extraneous  and  irritating  body  to  the  surrounding  bone,  in 
which  the  same  action  is  set  up  and  the  same  mortification  produced,  and 
thus  portion  after  x)ortion  is  successively  irritated  and  killed,  until  the 
whole  crown  of  the  tooth  is  destroyed." 

Fitch  (1829-35),  in  both  editions  of  his  work,  expresses  substantially 
the  same  view  as  did  I^eumann,  Hertz,  Koecker,  and  others. 

Koecker  says,  "Caries  of  the  teeth  must  be  considered  as  similar  to 
gangrene  in  other  parts  of  the  system.  And  when  we  speak  of  caries 
as  a  disease  we  mean  that  diseased  action  in  the  bony  structure  of  the 
living  tooth  produced  by  chemical  irritation  of  its  dead  and  rotten 
parts. 


DENTAL    CAEIES.  139 

"Hence  it  is  indispensable  that  we  should  make  a  due  distinction  be- 
tween caries  considered  as  a  disease  in  the  tooth  and  the  effect  of  that  dis- 
ease,— viz.,  mortification  and  putrefaction  of  its  whole  structure.  Caries, 
in  fact,  is  that  state  of  the  tooth  in  which  mortification  has  taken  place  in 
one  part,  and  inflammation  in  the  part  contiguous  to  it,  the  former  origi- 
nally produced  by  the  latter,  and  the  latter  continually  kept  up  by  the 
former. ' ' 

Koecker,  however,  maintained  that  there  were  two  forms  of  caries,  one 
beginning  upon  the  external  surface  of  the  tooth,  and  the  other  having  its 
origin  within.  The  latter  variety  he  looked  upon  as  analogous  to  an 
abscess  of  the  bone,  for  he  says,  "It  (the  disease)  never  proceeds  so  far 
towards  the  cavity  containing  the  nerves  as  to  render  this  membrane  alto- 
gether uniDrotected  by  the  bony  structure  before  it  has  penetrated  through 
the  external  osseous  parts,  including  the  enamel,  and  has  thus  formed  a 
natural  outlet  for  the  bony  abscess." 

Abbott  (1879),  Heitzmann,  and  Boedecker  (1886  and  1888)  made  the 
attempt  to  revive  the  vital  theory  of  caries.  Abbott  describes  caries  oc- 
curring in  a  vital  tooth  as  "an  inflammatory  process,  which,  beginning  as 
a  chemical  process,  in  turn  reduces  the  tissues  of  the  tooth  into  embryonic 
or  medullary  elements,  evidently  the  same  as,  during  the  development  of 
the  tooth,  have  shared  in  its  formation ;  and  its  development  and  inten- 
sity are  in  direct  proportion  to  the  amount  of  living  matter  which  they 
contain,  as  compared  with  other  tissues." 

He  opposed  the  idea  that  micro-organisms  in  any  sense  produced 
caries ;  that  these  organisms  did  not  penetrate  the  basis-substance  of  the 
tooth,  "but  appeared  only  as  secondary  formations,  owing  to  the  decay  of 
the  medullary  elements." 

These  authors  maintained  with  the  most  positive  assertions  that  "there 
occurs  a  primary  inflammation  in  dentin,  independent  of  pulpitis  or  iDeri- 
cementitis,  running  its  course  in  the  middle  of  the  dental  tissue,  and  leading,  as 
all  inflammatory  iDrocesses  do,  either  to  a  new  formation  or  to  destruction 
by  supijuration." 

They  explained  the  process  as  follows :  ' '  Inflammation  causes  first  a 
solution  of  the  lime-salts,  and  afterwards  a  liquefaction  of  the  basis-sub- 
stance, both  in  bone  and  dentinal  tissue.  The  result  will  be  the  appear- 
ance of  globular  spaces  or  bay -like  excavations,  which  exhibit  medullary 
corpuscles,  or  sometimes  clear  protoplasmic  masses  corresponding  to  the 
embryonal  stage  of  the  inflamed  tissue.  .  .  .  By  the  breaking  apart  of 
these  medullary  corx^uscles  pus  may  be  formed  in  the  middle  of  the 
dentin,  thus  representing  an  abscess  independently  of  the  pulp-tissue  ; 
or,  on  the  other  hand,  a  healing  process  may  take  place  through  the 
redeposition  of  lime-salts."  These- views  were  never  adopted  by  the  pro- 
fession in  general,  as  they  were  based  upon  alleged  facts  which  were 
entirely  foreign  to  the  teaching  of  the  best  authorities  in  morphology, 
histology,  and  pathology,  and,  furthermore,  others  were  not  able  to  demon- 
strate them. 

The  Worm  Theory  of  Caries. — Just  when  or  by  whom  the  theory 
that  worms  were  an  essential  factor  in  the  origin  and  develoiDment  of 


140  OPEEATIVE    DENTISTRY. 

caries  is  not  known,  but  it  is  certain  that  for  many  centuries  they  were 
regarded  as  the  cause  of  the  disease,  and  various  remedies  were  employed 
to  destroy  them  or  drive  them  out.  Scribonius  used  fumigations,  Ebu- 
Sina  employed  the  seeds  of  henbane,  leek,  and  onions.  Musetanus  (1114), 
Krautermann  (1732),  Euyleman  (1824),  Kremler,  and  many  others  recom- 
mended similar  measures.     (Miller.) 

Whether  this  theory  arose  as  the  result  of  imperfect  observation  or 
from  a  deliberate  intention  to  deceive,  history  does  not  enlighten  us.  The 
chances  are,  however,  that  it  was  invented  by  some  charlatan  who  desired 
to  defraud  the  public  and  thereby  fill  his  purse.  This  theory  is  commonly 
believed  in  China  at  the  present  day,  and  their  dentists  i)retend  to  remove 
such  parasites  from  the  teeth.  The  worms,  which  are  artificial,  are  dex- 
terously placed  in  the  mouth  of  the  patient  by  the  dentist  during  his 
manipulations,  and  then  extracted  and  held  up  to  the  gaze  of  the  wonder- 
ing but  satisfied  victim. 

Fauchard  (1728)  took  infinite  pains  to  discover  the  worms  which  were 
supposed  to  be  the  cause  of  the  disease,  and  the  odontalgia  which  was  a 
frequent  accompaniment  of  the  disintegration  of  the  tooth,  but  failed  to 
discover  them  either  in  the  carious  dentin  or  in  the  salivary  calculus. 

Pfaff  (1756)  discovered  worms  in  the  mouths  of  i)ersons  who  ate  decay- 
ing cheese,  but  he  was  ' '  not  able  to  observe  that  these  worms  had  pro- 
duced toothache  by  gnawing."     (Miller.) 

The  Putrefaction  Theory  of  Caries.— Pfaff  (1756)  was  the  first  to 
advance  the  theory  that  dental  caries  was  caused  by  putrefaction.  He 
says,  ''Eemains  of  food  which  undergo  putrefaction  between  the  teeth 
occasion  decay  of  the  teeth." 

Ficinus  (1847)  attributed  dental  caries  to  a  putrefaction  induced  by 
certain  minute  infusorial  animalcules  which  live  in  the  mouth,  and  to 
which  he  gave  the  name  Denticola.  He  believed  these  organisms  produced 
a  kind  of  putrefaction  which  first  attacked  the  enamel  cuticle,  then  pro- 
ceeded to  destroy  the  enamel,  and  afterwards  the  dentin.  The  process  of 
putrefaction  requires  an  alkaline  reaction,  but  he  does  not  explain  the  dis- 
appearance of  the  calcium  salts,  which  require  acids  for  their  solution. 
(Leber  and  Eottenstein. ) 

Klencke  (1850)  maintained  the  theory  of  putrefaction  as  the  cause  of 
caries,  but  divided  caries  into  two  distinct  Yarieties,— central  caries  and 
peripheric  caries.  The  former,  he  stated,  has  its  origin  in  the  pulp-cavity, 
the  latter  in  the  external  portions  of  the  teeth. 

Peripheric  caries  he  divided  into  three  different  forms  : 

1.  Soft  caries  (caries  acuta),  caused  by  the  agencies  of  putrefaction, 
dental  animal cula,  denticole  hominis. 

2.  A  soft  caries  (caries  acuta),  due  to  the  proliferation  of  a  s^egetable 
parasite  called  Frotococcus  dentalis. 

3.  The  so-called  dry  caries  (caries  chronica),  in  which  the  parasites 
have  no  part ;  this  form  being  caused  by  the  chemical  action  of  acids  upon 
the  dental  tissues. 

The  Chemical  Theory  of  Caries. — For  many  years,  and  up  to  a 
very  recent  period,  the  acid  theory  of  decay  received  the  support  of  a  large 


DENTAL   CARIES.  141 

majority  of  the  profession.  In  fact,  it  was  the  prevailing  theory  until  the 
researches  of  Miller  proved  the  disease  to  be  caused  by  the  zymogenic 
bacteria. 

Many  of  the  advocates  of  the  ''acid  theory"  taught  that  the  teeth 
when  once  formed  were  not  susceptible  to  change  in  structure,  and  that 
consequently  they  were  passive  in  the  hands  of  the  disease  5  that  the  cause 
of  caries  was  a  purely  chemical  one,  based  upon  the  known  fact  of  the 
af&nity  of  acids  for  calcium  salts. 

Although  the  chemical  theory  may  be  said  to  be  of  modern  origin,  it 
nevertheless  received  its  first  suggestions  from  some  of  the  older  writers. 
According  to  Miller,  Paul,  of  ^gina  (636),  first  suggested  the  idea  that 
acids  jnight  cause  caries.  He  says,  "In  order  to  preserve  the  teeth  pre- 
cautions should  be  taken  against  the  spoiling  of  food  in  the  stomach, 
since  the  frequent  vomiting  resulting  from  it  is  very  injurious  to  the 
teeth." 

Carabelli  is  authority  for  the  statement  that  the  first  experiments  in 
regard  to  the  action  of  acids  upon  the  teeth  were  made  by  Berdmore  (1771) 
with  nitric  and  sulphuric  acids.  Pasch  (1767),  Biicking  (1782),  Becker 
(1808),  and  Eingelmann  (1824)  all  attributed  injurious  effects  to  some 
foods  and  acids.     (Miller. ) 

Harris  (1830)  was  the  first  writer  to  announce  his  belief  that  caries 
was  caused  by  a  purely  chemical  process,  the  result  of  the  action  of  acids 
within  the  mouth  acting  upon  the  calcareous  material  of  the  tissues  of  the 
tooth. 

Robertson  (1835)  combated  the  vital  or  infiammatory  theory  of  the 
disease,  and  stated  that  caries  was  caused  by  a  chemical  decomposition  of 
the  dental  tissues  by  the  means  of  acids,  the  acids  being  formed  in  the 
mouth  by  the  dissolution  of  food  particles. 

Linderer  (1837)  considered  caries  to  be  due  to  a  purely  chemical 
process  induced  by  the  oral  fluids,  and  combated  the  inflauimation  theory, 
for,  ' '  since  dentin  contains  no  blood-vessels,  inflammation  in  this  tissue  is 
not  conceivable."  He  also  denied  the  existence  of  the  so-called  internal 
caries. 

Regnaud  (1838)  upheld  the  pure  chemical  theory  of  caries,  considering 
the  disease  to  be  the  result  of  the  destruction  of  the  dental  tissues  by 
acids  formed  within  the  mouth.  He  further  stated  that  silk  ligatures 
wound  around  the  teeth,  when  left  for  a  considerable  i)eriod,  cause  tlie 
destruction  of  the  enamel,  while  caps  covering  the  teeth,  whether  made 
of  wax  or  some  metallic  substance,  promote  their  destruction,  and  human 
teeth,  artificial  sets,  and  individual  teeth  made  from  ivory  also  undergo 
destruction. 

Westcott  (1843)  proved  conclusively  by  a  long  series  of  experiments 
that  acids,  both  vegetable  and  mineral,  act  more  or  less  vigorously  upon 
the  calcified  structures  of  the  teeth. 

AUport,  a  few  years  later,  conducted  a  similar  series  of  experiments 
with  the  vegetable  and  mineral  acids,  and  arrived  at  substantially  the 
same  conclusions. 

Desirabode  (1846)  recognized  two  forms  of  caries,  one  external,  which 


142  OPERATIVE    DENTISTRY. 

is  caused  by  a  chemical  destruction  acting  from  without  inward,  and  the 
other  internal,  arising  from  some  injury  to  the  pulp  or  from  a  congenital 
defect  in  the  dentin  and  developed  spontaneously  from  within  outward. 

Tomes  (1837)  was  contemporary  with  Eobertson,  and  in  his  earlier 
writings  his  views  were  quite  similar  to  those  of  Klencke.  In  his  later 
work  (1873)  he  concluded  that  caries  was  the  effect  of  external  causes  in 
which  the  so-called  vital  forces  play  no  part  ;  that  it  is  due  to  the  solvent 
action  of  acids  which  have  been  generated  by  fermentation  going  on  in 
the  mouth,  the  buccal  mucus  probably  playing  no  small  part  in  the  matter  ; 
and  when  once  the  disintegration  is  established  in  some  congenitally  de- 
fective point,  the  accumulation  of  food  and  secretions  in  the  oral  cavity 
will  intensify  the  mischief  by  furnishing  new  supplies  of  acids.  In  his 
third  edition  he  states  that  the  buccal  organisms  have  no  small  share  in 
the  matter  of  causing  the  disease. 

Tomes  was  the  first  to  accurately  describe  the  histologic  alterations 
which  take  place  at  the  seat  of  caries.  These  changes  in  the  enamel  he 
thought  were  caused  in  the  majority  of  cases  by  imperfect  development, 
with  a  greater  porosity  of  the  tissues,  the  porosity  increasing  with  the 
jDrogress  of  the  disease.  The  most  remarkable  changes  were  found  in  the 
canaliculi  of  the  dentin.  In  cross-section  they  were  seen  to  be  surrounded 
by  a  thickened  sheath,  having  a  tobacco-pipe-stemmed  appearance.  In 
completely  decalcified  dentin  the  canaliculi  with  their  enclosed  soft  fibrils 
— Tomes' s  fibrils — remain  free  in  the  softened  mass.  In  the  more  advanced 
stage  of  the  disease  he  found  these  elements  losing  the  sharpness  of  their 
contour  and  assuming  a  finely  granular  appearance.  When  the  progress 
of  the  disease  was  very  rapid,  the  dentinal  sheaths  presented  varicosities 
and  globular  swellings. 

These  pathologic  changes  proceed  along  the  canaliculi  towards  the 
pulp,  giving  usually  to  the  carious  or  infected  portion  of  the  dentin  the 
form  of  a  brownish  cone  with  its  base  turned  towards  the  enamel.  In 
those  cases  in  which  a  more  extended  surface  of  the  enamel  was  involved, 
and  where  the  destructive  process  was  rapid,  the  cone  existed  only  incom- 
pletely or  was  entirely  wanting.  Around  the  cone  of  discolored  dentin  a 
zone  of  relative  transparency  existed  in  which  the  canaliculi  contained 
caiciiied  dentinal  fibrils. 

These  changes  were  attributed  by  Tomes  to  organic  or  vital  reaction  of 
the  dentin  against  the  i^athologic  irritation  induced  by  the  caries,  and  he 
believed  retarded  or  arrested  the  progress  of  the  disease. 

Oudet  (1862)  described  two  distinct  forms  of  caries, — viz.,  external  and 
internal.  The  former  he  believed  to  be  caused  by  the  action  of  acids  upon 
the  inorganic  elements  of  the  tooth,  while  the  latter  was  the  result  of  in- 
flammatory action  occurring  within  the  substance  of  the  dentin,  which 
secondarily  involved  the  contiguous  portion  of  enamel. 

Watt  was  perhaps  the  most  conspicuous  and  aggressive  advocate  of  the 
purely  chemical  theory  of  dental  caries.  He  maintained  that  caries  was 
caused  by  mineral  acids  principally,  though  he  did  not  exclude  the  action 
of  the  organic  acids,  and  insisted  that  the  different  colors  seen  in  caries 
was  the  result  of  the  action  of  these  mineral  acids, — viz.,   nitric,  pro- 


DENTAL    CARIES.  143 

ducing  white  decay ;  sulpliuric,  black  decay ;  and  chlorohydric,  the 
intermediate  colors. 

Taft  in  his  earlier  writings  favored  the  chemical  theory  of  caries.  In 
his  05)inion,  ' '  acid  mucus  and  saliva,  vitiated  secretions,  products  of  de- 
composition of  animal  and  vegetable  matter  in  the  mouth,  galvanic  action, 
and  mineral  and  vegetable  acids,  were  the  chief  causes  of  dental  decay." 

Schenckler  believed  most  strenuously  that  acids  produced  caries,  for  he 
says,  ''Be  it  repeated,  where  there  is  no  acid  no  caries  is  possible." 

Baume  stoutly  maintained  the  correctness  of  the  chemical  theory,  and 
as  strongly  opposed  the  parasitic  theory.  He  said,  ^^Tlie  fungi  are  the 
result  of  the  caries.''^ 

Magitot  (1867),  in  his  "Treatise  upon  Dental  Caries,"  advocated  the 
purely  chemical  theory  of  caries,  claiming  that  the  disease  was  caused  by 
the  acids  contained  in  the  saliva,  or  formed  in  the  mouth  by  fermentation. 
He  states  as  his  conclusions,  reached  after  a  long  series  of  observations  and 
experiments  upon  natural  teeth  and  those  carved  from  ivory,  under  both 
natural  and  artificial  conditions  :  1.  That  dental  caries  is  a  purely,  chemi- 
cal alteration  of  the  enamel  and  dentin.  2.  That  the  disease  always 
progresses  from  the  external  surface  of  the  organ  inward,  attacking  first 
the  enamel,  second  the  dentin,  and  third  the  pulp,  and  that  the  existence 
of  internal  caries  cannot  be  fairly  pro\ed.  3.  Disorganization  of  the 
enamel  is  a  purely  passive  chemical  process.  4.  That  in  vital  teeth  there 
is  developed  between  the  caries  of  the  dentin  and  the  pulp  a  "cone  or 
white  zone  formed  by  a  mass  of  canaliculi  obliterated  in  consequence  of  a 
formation  of  secondary  dentin."  This  he  terms  the  cone  of  resistance,  and 
looks  upon  it  as  an  effort  of  nature  to  resist  or  retard  the  progress  of  the 
disease.  5.  That  artificially  produced  caries  presents  the  same  phenom- 
ena as  natural  caries,  with  the  exception  of  the  evidences  of  organic  or 
vital  resistance. 

The  Electro-Chemical  Theory. — This  theory  was  promulgated  by 
Bridgman  (1861-63),  and  endorsed  by  the  Odoutological  Society  of  London. 

The  discovery  by  Faraday  of  the  simple  galvanic  battery — viz.,  that  a 
copper  or  zinc  rod,  with  one  end  immersed  in  a  dilute  solution  of  sulphuric 
acid  in  water  and  the  other  exposed  to  the  atmosphere,  soon  became  polar- 
ized, and  that  at  a  point  on  the  rod  corresx^onding  to  the  surface  of  the 
liquid  the  metal  was  gradually  eroded  and  the  material  carried  up  the 
rod  and  deposited  upon  the  portion  exposed  to  the  atmosphere,  the  acid 
forming  one  element  of  the  battery,  and  the  oxygen  of  the  atmosphere 
the  other — suggested  to  the  mind  of  Bridgman  that  here,  perhaps,  was 
the  solution  of  the  vexed  question  of  the  cause  of  dental  caries.  He  there- 
upon instituted  a  series  of  experiments  upon  teeth  out  of  the  mouth  under 
conditions  as  nearly  like  those  obtaining  within  the  mouth  as  he  could 
compass,  with  the  result  of  producing  caries  artificially,  which  in  appear^ 
ance  was  identical  with  that  produced  out  of  the  mouth  by  acids,  and  in 
general  features  corresponded  to  the  microscopic  appearance  of  natural 
caries. 

He  argued  from  this,  applying  the  principles  involved  in  the  discovery 
of  Faraday,  that  a  tooth  in  the  living  body  was  always  polarized,  and  had 


144  OPERATIVE    DENTISTRY. 

well-establisli'ed  electric  currents,  that  the  root  of  the  tooth  when  invested 
with  the  glim  and  alveohis,  like  the  end  of  the  rod  immersed  in  the 
dihite  sulphuric  acid,  possessed  electro-positive  qualities,  while  the  crown 
of  the  tooth,  like  the  free  end  of  the  rod,  being  exposed  to  the  atmos- 
phere, had  electro-negative  qualities,  consequently  each  tooth  was  a  minia- 
ture galvanic  battery,  and  whenever  fluid  or  moist  pulpy  material  was 
permitted  to  remain  undisturbed  in  one  position,  as  in  the  sulci  and 
approximal  spaces,  for  a  few  hours,  the  electric  currents,  which  are  con- 
stant, decompose  them,  and  as  a  result  acids  are  formed  which  attack  the 
lime-salts  of  the  tooth,  and  caries  is  established. 

He  further  claimed  that  the  insertion  of  metal  j^lugs  within  the  teeth 
increased  the  galvanic  action  and  also  accounted  for  secondary  caries. 

Palmer,  Chase,  and  Flagg  endorsed  the  views  of  Bridgman  in  reference 
to  the  production  of  secondary  caries,  and  becanie  the  sponsors  of  what  is 
known  as  the  New  Departure  Theory  in  relation  to  the  relative  values  of 
the  various  filling-materials  as  conservers  of  tooth-structure.  These 
gentlemen  instituted  a  long  line  of  experiments  to  establish  the  position, 
in  the  electro-chemical  series,  of  dentin  with  the  various  filling-materials. 
These  experiments  resulted  in  the  demonstration  of  the  following  scale  : 
Electro-negative :  gold ;  amalgam,  tin,  gutta-percha,  dentin,  oxychloride 
of  zinc  -^  electro-positive. 

The  strongest  electro-motive  force  or  electric  action  is  therefore  gen- 
erated by  a  combination  of  gold  and  dentin,  and  in  a  decreasing  ratio 
amalgam  and  dentin,  tin  and  dentin,  gutta-percha  and  dentin.  Palmer 
claimed  that  these  materials  in  the  order  named  above  possessed  a  com- 
patibility with  tooth-structure  in  an  increasing  ratio, — viz.,  gold  being  the 
least  compatible,  and  the  ratio  increasing  to  the  bottom  of  the  list. 

These  authors  and  their  followers  have  claimed  further  that  the  varia- 
bility in  the  structure  of  the  teeth  plays  an  important  part  in  the  liability 
to  secondary  caries  ;  teeth  of  low  organization — "of  greater  porosity" — 
furnishing  the  most  favorable  conditions  for  a  recurrence  of  the  disease 
after  the  tooth  had  been  filled,  and  those  of  the  highest  organization  offering 
the  least  favorable  conditions.  Moisture  is  necessary  in  order  to  establish 
galvanic  action  between  the  filling- material  and  the  dentin.  This  moisture 
is  furnished  by  the  fluids  of  the  mouth  which  act  at  the  margins  of  the 
filling,  but  it  has  been  claimed  that  the  tooth  itself  also  furnishes  moisture 
through  its  tubuli  which  in  teeth  of  low  organization  would  be  sufficient 
to  establish  galvanic  currents  between  the  tooth  and  the  filling-material, 
followed  by  decomposition  of  the  fluid,  the  formation  or  liberation  of 
acids,  and  decalcification  of  tooth-structure. 

The  Germ  Theory. — In  discussing  the  various  relations  of  micro- 
organisms to  the  process  of  fermentation,  it  has  been  frequently  suggested 
that  caries  of  the  teeth  might  be,  in  part  at  least,  caused  by  the  action  of 
micro-organisms. 

Erdl  (1845)  was  the  first  to  definitely  state  that  dental  caries  was  caused 
by  parasites.  These,  he  claimed,  formed  upon  the  crown  as  a  delicate, 
colorless  membrane,  composed  of  cells,  which  later  became  more  irregular 
and  their  nuclei  more  distinct.     Miller  thinks  that  inasmuch  as  Erdl  em- 


DENTAL    CAEIES.  145 

ployed  muriatic  acid  to  isolate  the  ''caries  matter,"  that  it  is  C[uite  prob- 
able that  the  delicate  membrane  which  he  obtained  was  nothing  more  than 
^asmyth's  membrane.  Erdl  applied  creosote  and  nitric  acid  to  destroy 
the  parasites  and  prevent  the  progress  of  the  disease.  His  method  was 
first  to  apply  creosote  until  the  ' '  caries  matter' '  was  impregnated  with  it, 
then  nitric  acid,  the  latter  immediately  producing  a  violent  and  comxDlete 
decomposition  of  the  creosote  and  of  the  parasites  saturated  with  it. 

Ficinus,  in  1847,  suggested,  as  we  have  already  seen,  that  the  organisms 
of  putrefaction — his  denticolce — were  the  active  agencies  which  produced 
the  disease.  These,  he  claimed,  proliferated  in  Nasmyth's  membrane, 
which  they  destroyed  ;  they  next  attacked  the  material  between  the  enamel 
prisms,  thus  decomposing  this  structure  and  penetrating  the  dentin,  which 
they  destroyed  in  the  same  manner. 

Klencke  (1850)  discovered  another  parasite  in  the  human  mouth,  which 
he  denoininated  protococcus  dentalis,  and  claimed  that  this  fungus  i^ossessed 
the  power  of  liquefying  enamel  and  dentin.  He  says  of  it  that  it  '''softens 
and  destroys  dental  substances,  and  is  nourished  by  their  chemical 
elements." 

The  first  extended  study  of  the  organisms  which  are  found  in  the  mouth 
was  undertaken  by  Leber  and  Rottenstein,  and  the  results  of  their  labors 
were  published  in  1867.  These  authors  believed  that  there  were  two  forms 
of  caries,  one  M-hich  they  denominated  central  caries,  having  its  origin  in 
the  cavity  of  the  pulj),  but  an  exceedingly  rare  form,  and  another  to  which 
is  applied  the  term  external  caries,  having  its  origin  in  the  enamel,  and 
caused  by  external  influences. 

In  reference  to  central  caries,  they  presented  a  single  case  in  illustra- 
tion, in  which  three  teeth  (two  superior  and  one  inferior  incisor)  in  the 
mouth  of  a  lady  twenty-one  years  of  age  had  lost  their  vitality  from  a 
traumatism,  —  a  fall  in  early  childhood.  The  teeth  were  blue  in  color,  but 
there  was  no  evidence  of  caries  having  penetrated  from  the  surface.  "In 
piercing  the  xDOsterior  face  of  one  of  these  teeth  it  was  found  completely 
softened,  even  to  the  enamel,  and  the  tissues  had  a  brown  color.  The  root 
itself  was  hollowed  to  a  considerable  extent.  The  same  was  found  to  be 
the  case  with  one  of  the  other  teeth.  The  third,  whose  color  was  not  so 
marked,  and  which  caused  no  unpleasant  sensation,  was  let  alone." 

Microscopic  examination  was  not  i^ossible,  hence  doubt  must  exist  in 
relation  to  the  supposition  that  caries  did  not  originate  from  some  micro- 
scopic defect  in  the  enamel. 

These  authors  do  not  attempt  to  explain  the  cause  which  produced  the 
central  caries  (%),  but  say,  ' '  We  believe  that  there  exist  cases  where  the 
dental  tissues  are  attacked  and  destroyed  from  the  cavity  of  the  pulp  ;  but 
these  cases  are  extremely  rare,  and  the  conditions  of  their  production  are 
uot  yet  well  understood,  except,  perhaps,  the  previously  necessary  death 
of  the  tooth." 

With  regard  to  external  caries,  they  were  of  the  opinion  that  the  disease 
commences  as  a  purely  chemical  process,  but  that  as  soon  as  the  enamel  is 
dissolved  and  the  surface  of  the  dentin  exposed  the  elements  of  the  lepto- 
thrix  buccalis  enter  and  penetrate  the  dental  canaliculi,  enlarging  them, 

10 


146  OPERATIVE    DENTISTRY. 

and  thus  increasing  the  facilities  for  the  penetration  of  the  acids  which 
dissolve  the  lime-salts. 

Weil  (1880),  writing  in  support  of  Leber  and  Eottenstein's  view  of 
caries,  says,  '^  Decay  generally  begins  from  without,  and  must,  therefore, 
first  make  its  way  through  the  enamel-cuticle. 

"It  is  highly  probable  that  the  fungus  {leptothrix  buecalis)  bores 
directly  through  it.  The  fungi  now  proceed  farther  into  the  enamel,  and 
force  its  prisms  apart,  gradually  disorganizing  its  structure.  From  the 
enamel  they  i3enetrate  into  the  tubules  of  the  dentin,  which  are  often  en- 
larged by  them  to  two  or  three  times  their  original  size,  at  the  same  time 
dissolving  the  calcium  salts." 

Arkdvy  stated  the  disease  was  "brought  about  by  chemical  action,  in 
which  the  invasion  of  nosogenous  fungi  play  an  essential  part." 

Milles  and  Underwood,  in  a  paper  presented  to  the  International 
Medical  Congress,  held  in  London  in  1881,  gave  new  interest  to  the  germ 
theory  of  dental  caries,  and  marked  the  most  important  advance  made  in 
the  discovery  of  the  causes  of  the  disease  up  to  this  time. 

The  work  of  Leber  and  Eottenstein  had  found  but  few  advocates,  and 
had  only  stirred  a  passing  interest  in  the  subject,  as  the  profession  in 
general  seemed  satisfied  with  the  acid  theory  of  the  disease. 

The  marked  success,  however,  of  Lister  (1865-69)  in  the  treatment  of 
wounds,  which  was  based  upon  the  discoveries  of  Pasteur  in  relation  to 
the  organisms  of  the  various  ferments,  added  new  interest,  and  stimulated 
investigation  into  the  theory  advanced  by  Leber  and  Eottenstein  of  the 
etiology  of  dental  caries. 

Koch  (1881)  added  greatly  to  the  facilities  for  observing  these  micro- 
organisms by  the  introduction  of  his  improved  methods  of  staining,  and 
made  it  possible  for  later  investigators  to  escape  the  errors  into  which 
their  predecessors  had  fallen. 

Milles  and  Underwood,  noticing  the  constant  presence  of  micro- 
organisms in  decaying  dentin,  and  the  equally  constant  enlargement  of 
the  dentinal  tubuli,  came  to  the  conclusion  that  in  the  i^rocess  of  dental 
decay  "two  factors  were  always  in  operation, — first j  the  action  of  acids, 
and  second,  the  action  of  germs. 

This  theory,  which,  for  the  sake  of  distinction,  may  be  called  the  septic, 
is  rather  an  amxDlification  of  the  chemical  theory  than  a  contradiction  of  it. 

They  say,  "Most  probably  the  work  of  decalcification  is  entirely  per- 
formed by  the  action  of  acids,  but  these  acids  are,  we  think,  secreted  by 
the  germs  themselves,  and  the  organic  fibrils  upon  which  the  organisms 
feed,  and  in  which  they  multiply,  are  the  scene  of  the  manufacture  of  their 
characteristic  acids,  which  in  turn  decalcify  the  matrix  and  discolor  the 
whole  mass." 

In  reference  to  caries  of  cementum  they  say,  ' '  From  our  observations 
on  cementum  to  which  caries  has  extended,  we  conclude  that  the  process  is 
very  similar  ;  the  bioplasmic  contents  of  the  lacunae  and  canaliculi  afford 
food  and  lodging  for  the  organisms,  which  multiply,  and  when  sufficiently 
numerous  decalcify  the  surrounding  bone  so  that  each  lacuna  loses  its  out- 
line and  extends  in  all  directions." 


DENTAL    CARIES.  147 

Miller  (1882)  anuonnced  the  results  of  a  series  of  experiments  which, 
he  had  conducted  in  relation  to  the  active  causes  of  dental  caries,  that  it 
was  his  opinion  that  the  first  stage  of  the  disease  consisted  of  a  decalcifica- 
tion of  the  tissues  of  the  teeth  by  acids  which  are,  for  the  greater  part, 
generated  in  the  mouth  by  fermentation.  In  this  he  agrees  with  Leber 
and  Eottenstein,  and  partiallj^  with  Milles  and  Underwood. 

In  his  later  studies,  which  were  published  in  the  Independent  Prac- 
titioner, 1884  and  1885,  he  carried  the  subject  much  farther,  and  arrived  at 
conclusions  which  have  been  generally  accepted,  and  now  form  the  basis 
of  the  j)reseut  teaching  upon  this  subject. 

He  says,  in  summarizing  his  work  (1884), — 

^'1.  I  convinced  myself  by  the  examination  of  some  thousands  of 
slides  of  carious  dentin  that  micro-organisms  were  always  present,  and  that 
they,  without  any  doubt,  were  the  cause  of  various  anatomical  changes 
which  were  found  to  take  place  in  the  structure  of  the  dentin  during 
caries.  (Here,  of  course,  the  question  of  priority  does  not  suggest  itself ; 
Leber  and  Eottenstein,  as  is  well  known,  were  the  first  to  give  definite 
expression  to  this  fact.) 

'^2.  I  proved,  at  the  same  time,  that  the  invasion  of  micro-organisms 
was  not,  in  the  large  majority  of  cases,  simultaneous  with  the  softening 
of  the  dentin,  but  that  large  areas  of  softened  dentin  could  be  found  that 
contained  no  fungi. 

'  •  Of  all  those  who  examined  my  preparations  in  America,  no  one,  what- 
ever his  theory,  ever  once  denied  this  fact.  I  concluded  from  this  that  the 
softening  of  the  dentin  went  in  advance  of  the  invasion  of  the  organisms. 

' '  3.  I  determined,  by  analysis  of  masses  of  carious  dentin  sufficiently  large 
to  give  reliable  results,  that  the  softening  of  the  dentin  is  of  the  nature  of  a 
true  decalcification  ;  that  the  decalcification  of  the  outer  layers  is  almost 
complete  and  diminishes  in  degree  as  we  advance  towards  the  normal 
dentin ;  furthermore,  that  the  same  relations  maintain  in  dentin  softened 
in  a  mixture  of  saliva  and  bread,  or  in  weak  organic  acids  ;  also,  that  in  a 
mass  of  carious  dentin  the  lime-salts  had  been  removed  to  a  much  greater 
extent  than  the  organic  matter. 

"4.  I  maintained  from  the  first  that  the  softening  of  the  dentin  was 
produced  by  acids  for  the  most  part,  generated  in  the  mouth  by  fermenta- 
tion.    I  had,  however,  no  proof  of  this. 

"5.  I  proved  that  fungi  exist  in  great  numbers  in  the  human  saliva  and 
in  carious  dentin,  which  have  the  power  to  produce  acid  under  conditions 
which  are  constantly  present  in  the  human  mouth.  I  determined  this  acid 
— for  one  of  the  fungi  at  least — to  he  the  ordinary  ferment,  lactic  acid. 

^■6.  I  produced  caries  artificially,  which  under  the  microscope  cannot 
be  distinguished  from  natural  caries,  by  subjecting  sound  dentin  to  the 
action  of  these  fungi  in  these  fermentable  solutions. 

"7.  I  determined  the  influeuce  of  various  antiseptics  and  filling-mate- 
rials upon  the  fungi  of  caries. 

' '  8.  I  isolated  various  forms  of  these  fungi,  and  determined,  in  part, 
the  conditions  most  favorable  to  their  development,  their  characteristic  re- 
action upon  gelatin,  their  physiologic  action,  their  effect  when  inoculated 


148  OPERATIVE    DENTISTRY. 

into  the  system  of  lower  animals,  and  their  possible  connection  with 
certain  obscure  diseases  generally  attributed  to  the  carelessness  of  the 
dentist." 

J.  Sim  Wallace  *  (1899)  contends  that  caries  is  in  no  wise  an  inherited 
affection,  nor  is  heredity  a  predisposing  factor,  but  that  certain  inherited 
l^eculiarities  of  the  teeth  might  favor  the  lodgement  of  food  and  micro- 
organisms and  thus  predispose  to  caries  ;  and  that  the  environment  of  the 
teeth  and  consequent  liability  to  caries  is  similar  in  certain  families  and 
races,  on  account  of  the  similarity  in  diet  and  other  customs. 

An  important  factor  in  the  predisposition  to  caries  lies  in  the  relative 
lodgeability  of  the  various  food-stuffs.  He  believes  the  fibrous  food-stuffs 
have  a  detergent  action  upon  caries,  in  that  these  foods  are  less  liable  to  acid 
fermentation.  Comparing  the  conditions  of  the  mouth  following  a  meal 
made  from  flesh  of  any  kind  and  that  following  a  meal  made  from  starchy 
foods,  a  marked  difference  is  noticed  in  their  relative  cleanliness.  In  the 
former  the  mouth  is  comparatively  clean,  only  a  few  fibres  remaining 
between  the  teeth,  and  these  easily  removed,  while  in  the  latter  the  inter- 
approximal  spaces  and  the  fissures  of  the  teeth  are  packed  full  of  fer- 
mentable material,  which  is  difficult  to  thoroughly  remove,  and  thus  are 
established  all  the  conditions  which  are  most  favorable  for  the  production 
of  lactic  acid  fermentation  and  the  decay  of  the  teeth. 

Mouth-Bacteria  and  Carbohydrates. — The  chief  source  of  nourish- 
ment for  micro-organisms  in  the  human  mouth,  according  to  Miller,  is 
furnished  by  two  groups  of  substances,  the  carbohydrates  and  the  albu- 
minoid substances.  These  are  almost  constantly  found  in  the  human 
month,  either  in  the  sulci  and  fissures  of  the  teeth,  in  the  approximal 
spaces,  or  upon  their  free  surfaces.  These  substances  are  readily  acted 
upon  by  the  zymogenic  and  saprogenic  bacteria.  In  all  forms  of  fermen- 
tation there  is  a  limit  under  ordinary  circumstances  to  the  quantity  of  the 
waste  products  produced  by  zymogenic  bacteria. 

Black  states  :  ''  It  is  an  established  law  that  the  waste  products  of  an 
organism  become  poisonous  to  that  organism  when  they  have  collected  in 
a  certain  quantity.  This  is  true  of  urea  in  the  animal,  it  is  true  of  alco- 
hol in  the  vinous  fermentation,  and  Miller  found  it  to  be  true  of  the 
organism  causing  caries.  When  lactic  acid  has  accumulated  in  certain 
quantity  (this  amount  not  yet  definitely  determined)  the  further  develop- 
ment of  the  organism  is  interfered  with.  Their  power  to  go  on  producing 
lactic  acid  in  the  depths  of  the  dentin  is  accounted  for  by  the  formation, 
from  the  lime-salts  of  the  tooth,  of  the  lactate  of  lime,  which  does  not  in- 
terfere with  the  further  development,  and,  in  fact,  is  equivalent  to  a  removal 
of  the  waste  i)roduct.  Long  before  the  existence  of  a  sj)eQial  organism  in 
lactic  fermentation  was  known,  it  had  been  found  that  by  adding  chalk  or 
other  form  of  lime  the  fermentation  could  be  continued  and  much  more 
lactic  acid  produced.  Following  up  these  facts.  Miller  has  analyzed 
carious  dentin  and  found  it  to  contain  calcium  lactate. ' ' 

From  the  foregoing  facts  the  student  will  readily  understand  why,  as  a 

*  The  Cause  and  Prevention  of  Decay  in  Teeth. 


DENTAL    CARIES.  149 

rule,  dental  caries  wlien  once  establislied  steadily  progresses — more  or  less 
rapidly — until  the  tooth  is  completely  destroyed. 

Were  it  not  for  the  presence  of  the  calcium  in  the  structures  of  the 
tooth  with  which  the  lactic  acid  combines,  forming  lactate  of  calcium,  the 
waste  product  of  the  organism — lactic  acid — would  soon  destroy  the  bac- 
terium, and  the  j)rogress  of  the  disease  would  be  arrested. 

The  carbohydrates  in  undergoing  fermentation  produce  an  acid  reac- 
tion, while  the  decomposition  or  putrefaction  of  the  albuminoid  sub- 
stances j)resent  an  alkaline  reaction.  When  these  substances  are  mixed 
they  are,  as  a  rule,  accompanied  by  an  acid  reaction.  Consequently  the 
reaction  from  the  fermentation  of  food  debris — which  is  usually  composed 
of  carbohydrates  and  albuminoids — will  be  found  most  often  to  give  an  acid 
reaction.  This,  however,  is  not  an  invariable  rule,  for  Miller  found  that 
the  reaction  depended  partly  upon  the  nature  of  the  food  found  in  a  par- 
ticular part  of  the  mouth  at  tlie  time  and  partly  ui)on  the  particular  kind 
of  bacterium  which  was  acting  upon  it. 

In  the  case  of  one  bacterium  which  he  examined  in  reference  to  this 
question,  he  found  that  when  it  was  cultivated  in  a  three  per  cent,  solution 
of  beef  extract,  in  the  presence  of  one-tenth  per  cent,  of  sugar,  it  gave  a 
neutral  reaction,  but  upon  increasing  the  amount  of  sugar  the  reaction 
became  acid,  and  upon  diminishing  it  the  reaction  became  alkaline. 

Miller,  in  another  series  of  experiments  instituted  to  determine  the 
action  of  the  mouth  bacteria  ui^on  the  carbohydrates,  found  that  out  of 
twenty-two  varieties,  sixteen  in  a  very  short  time  produced  an  acid  re- 
action when  cultivated  in  beef-extract,  peptone-sugar  solutions  ;  four  under 
the  same  conditions  gave  an  alkaline  reaction,  while  in  only  two  did  the 
reaction  remain  neutral. 

Following  this  with  another  series  of  experiments  with  twenty-five 
mouth-bacteria,  thirteen  stomach-ba,cteria,  and  fourteen  intestinal  bac- 
teria, instituted  for  the  same  purpose,  sixteen  of  the  mouth-bacteria  gave 
an  acid  reaction,  four  alkaline,  and  five  inconstant  results  ;  of  the  thirteen 
stomach-bacteria,  nine  produced  an  acid  reaction,  two  alkaline,  and  two 
inconstant  results  ;  of  the  fourteen  intestinal  bacteria,  six  gave  an  acid 
reaction,  five  alkaline,  and  three  inconstant  results.  Miller,  in  his  next 
series  of  experiments,  undertook  the  task  of  demonstrating  by  qualitative 
analysis  the  character  of  the  acids  formed  by  the  acid  producing  mouth- 
bacteria.  It  was  generally  believed  up  to  this  time  that  the  lactic  acid 
fermentation  could  not  be  brought  about  except  in  the  presence  of  one 
specific  micro-organism, — viz.,  the  hacterium  acidi  lactici.  Miller  had  dis- 
covered, however,  some  time  previously,  that  severed  forms  of  bacteria 
found  in  the  human  mouth  were  capable  of  forming  lactic  acid  out  of 
sugar.  This  discovery  has  since  been  verified  and  established  by  various 
investigators,  as  well  as  the  fact  that  a  large  number  of  bacteria  are  pos- 
sessed of  inverting  and  peptonizing  properties. 

Out  of  eighteen  different  forms  of  acid  producing  bacteria,  Miller  found  as 
a  result  of  his  labors  that  ten  of  them  produced  lactic  acid.  Among  the 
other  products  of  fermentation  of  these  bacteria  were  formic,  acetic,  and 
butyric  acids,  ''the  latter,  however,  in  very  small  quantities." 


150  OPERATIVE    DENTISTRY. 

Lactic  acid,  however,  requires  for  its  production  in  the  mouth, — 

1.  Substances  which  are  capable  of  being  converted  into  glucose, 
G3Hi20g, — viz.,  the  three  groups  of  carbohydrates, — glucoses,  C,;Hj.,Ob;  sac- 
charoses, C12II22O11 ;  and  amyloses,  CgHj^O^. 

The  carbohydrates  of  the  glucose  group  which  are  most  common  in  the 
food  of  human  beings  are  grape-sugar  (dextrose)  and  fruit-sugar  (levulose), 
cane-sugar  of  the  saccharose  group,  and  starch,  cellulose,  and  gum  in  the 
amy  lose  groui3. 

Hydration  converts  grape-sugar  into  two  fermentable  substances,  levu- 
lose and  dextrose,  their  chemical  composition  being  the  same,  CgHijOg. 
This  change  is  brought  about  by  the  action  of  such  organized  ferments  as 
ptyalin  and  amylopsin.  The  conversion  of  starch  into  glucose  is  repre- 
sented by  the  following  formula  :  ^eHw^s  +  ^1^  =  ^J^vS-^q- 

"^  °  starch.  Glucose. 

2.  The  fermentable  carbohydrates  must'  be  acted  upon  by  ferments 
capable  of  converting  these  substances  into  lactic  acid.  These  ferments 
are  constantly  found  in  the  human  mouth  in  the  form  of  various  zymo- 
genic bacteria,  while  the  necessary  conditions  for  their  growth  and  devel- 
opment— ^heat  and  moistuie — are  ever  present. 

The  fungi  have  the  power  to  cause  the  sugar  to  split  up  without  the 
formation  of  carbon  dioxide,  a  molecule  of  glucose,  CgHjjOg,  forming  two 
molecules  of  lactic  acid,  2C3Hg03, 

It  is  noticeable,  however,  that  caries  does  not  always  progress  with 
the  same  rapidity  in  the  same  individual  or  in  different  individuals  ;  that 
the  character  of  the  disease  is  not  always  the  same ;  that  certain  teeth 
are  attacked,  to  the  exclusion  of  others,  while  there  is  a  marked  differ- 
ence in  the  extent  of  the  disease  between  individuals  and  in  the  same 
individual  at  different  periods  of  life,  and  under  varying  conditions  of 
health. 

The  question  very  naturally  arises  as  to  the  cause  or  causes  for  these 
differences.  Are  they  due  to  the  degree  of  vital  resistance  possessed  hy  the  indi- 
vidual at  the  time,  or  hy  individual  teeth  ?  Or  are  there  conditions  operative 
within  the  mouth  which  favor  the  groivth  of  the  lactic  acid  lyrodncing  ferments 
at  one  time  and  retarding  them  at  another  f  It  is  not  at  all  improbable  that 
in  the  multitude  of  mouth-bacteria  some  form  inimical  to  the  growth  of 
lactic  acid  forming  organisms  may  under  certain  conditions  gain  the  as- 
cendency for  a  time,  and  thus  in  a  measure  control  the  production  of  the 
lactic  acid  ferment.  The  further  study  of  these  organisms  may  yet  dis- 
cover such  a  bacterium  which,  introduced  into  the  mouth,  will  retard  or 
prevent  the  growth  of  lactic  ferments,  and  thus  solve  the  problem  of  the 
prophylaxis  of  dental  caries. 

The  tendency  to  caries  is  always  augmented  in  certain  forms  of  disease, 
like  the  continued  fevers,  tuberculosis,  anaemia,  and  all  wasting  affections. 
These  abnormal  conditions  of  health  not  only  reduce  the  vital  resistance 
of  the  general  system  and  lower  the  vis  oiaturce  of  individual  tissue,  but 
they  produce  abnormal  conditions  of  the  buccal  secretions  which  favor  the 
growth  of  the  zymogenic  mouth-bacteria.  It  is  therefore  possible  that  both 
of  these  factors  act  together  under  the  conditions  indicated,  not  only  to  in- 


DENTAL    CARIES.  151 

crease  tlie  tendency  to  caries,  but  also  the  extent  of  the  disease  and  the 
rapidity  of  its  progress. 

Mouth-Bacteria  and  Albuminoids. — It  is  generally  recognized  at 
the  present  time  that  a  great  number  of  the  bacterial  forms  possess  the 
power  of  liquefying,  digesting,  or  peptonizing  coagulated  albumin  and 
collagen,  which  forms  the  basis  substance  of  dentin  and  bone. 

Miller  says,  '^  By  far  the  majority  of  mouth  bacteria,  in  fact,  of  all  bac- 
teria, possess  an  action  similar  to  pepsin,  in  converting  coagulated  albu- 
min into  soluble  modifications."  The  bacteria  possess  the  power  of  pep- 
tonizing these  substances  in  either  an  acid,  alkaline,  or  neutral  medium, 
while  pepsin  acts  only  in  the  presence  of  acids,  preferably  hydrochloric. 
Albuminoid  substances  are,  therefore,  excellent  media  upon  which  to 
cultivate  bacteria. 

Miller  found  the  products  of  mouth  bacteria  cultivated  upon  albu- 
minoid substances  to  be  the  same  as  those  developed  from  the  i^utrefaction 
of  organic  substances  in  general. 

These  are  principally  malodorous  and  noxious  gases — sulphuretted 
hydrogen  (H.S),  ammonia  (NH3),  carbon  dioxide  (COJ — and  numerous 
substances,  such  as  formic,  acetic,  butyric,  valeric,  and  other  acids. 

He  also  found  that  four  of  the  mouth  bacteria  which  he  examined 
would  not  grow  upon  coagulated  albumin  ;  six  had  but  a  limited  growth, 
while  all  the  others  ' '  developed  comparatively  well,  in  some  cases  com- 
pletely liquefying  the  albumin." 

It  will  thus  be  seen  that  the  mouth  bacteria  are  capable  of  producing 
dental  caries,  that  certain  of  them  possess  the  necessary  proi)erties  for 
forming  acids,  which,  acting  upon  the  lime-salts  of  the  enamel,  disinte- 
grate this  tissue  and  thus  permit  the  entrance  of  these  organisms  into  the 
dentinal  tubuli,  where  they  continue  the  process  by  dissolving  or  abstract- 
ing the  lime-salts  from  the  dentin,  and  that  afterwards  certain  other  forms 
liquefy,  peptonize,  or  digest  the  basis  substance,  thus  removing  the  organic 
tissue  and  forming  a  cavity  of  decay. 

Bastyr  (1885),  in  commenting  upon  the  active  causes  of  dental  caries, 
says,  ''As  long  as  it  cainiot  be  shown  that  the  appearances  observed  in  the 
decay  of  living  teeth,  decay  of  dead  (x3ulpless)  teeth  in  the  mouth,  and 
artificial  caries  show  any  appreciable  diiferences,  so  long  will  every 
attempt  to  explain  decay  as  a  vital  process  be  very  difBicult." 

Black  (1886),  in  discussing  the  germ  theory  of  caries  as  promulgated 
by  Miller,  says,  "The  fungus  has  no  power  of  attacking  anything,  or 
growing  into  anything,  except  it,  be  a  thing  that  offers  spaces  filled  with 
soft  tissue,  or  openings  into  which  it  may  grow  as  the  vine  grows  through 
spaces  in  a  lattice- work. 

"  It  is  not  the  organism  that  makes  the  attack,  but  the  products  of  the 
organism,  the  lactic  acid. 

"When  the  dental  tubules  are  once  exposed,  they  form  a  protection 
to  those  filaments  of  the  fungus  which  strike  into  them  in  the  process  of 
growth,  and  development  occurs  in  that  direction.  Hence  the  continuous 
progress  of  caries  when  it  has  once  fairly  begun  in  the  dentin.  Then  the 
growth  will  continue  in  any  direction  in  which  space  is  offered  for  the 


152  OPERATIVE    DENTISTRY. 

development  of  filaments.  In  this  way  the  tubules  become  packed  full 
of  the  organisms,  and  the  surrounding  dentin  is  always  decalcified  in 
advance  of  the  growth  of  the  fungus  by  the  lactic  acid  produced.  That 
this  is  the  true  explanation  of  the  etiology  of  dental  caries  there  is  no 
longer  a  reasonable  doubt." 

Gysi  (1887),  in  writing  upon  the  chemico-parasitic  theory  of  caries, 
remarks,  "As  all  my  experiments  and  investigations  upon  this  subject 
have  presented  facts  which  are  consistent  with  it,  I  accept  it  as  a  satisfac- 
tory explanation  of  the  etiology  of  the  disease." 

Pierce  (1888)  endorsed  this  theory  in  the  following  words  :  "I  am  a 
firm  believer  in  the  fact  that  dental  caries  cannot  progress  without  these 
low  forms  of  life." 

Sudduth  (1888)  says,  "Dr.  Miller's  theory  of  the  formation  of  cavities 
by  the  action  of  a  digestive  ferment  upon  the  basis  substance  of  dentin 
has  been  the  only  theory  ever  advanced  that  explained  the  formation  of 
cavities." 

Allan  (1889)  maintains  that  "the  germ  theory  is  the  only  one  so  far 
presented  that  clearly  and  satisfactorily  accounts  for  the  acid,"  and,  fur- 
ther, that  ' '  the  '  germ  theory'  fully  explains  the  distended  tubules  and 
the  broken-down  basis  substance." 

Caries  of  the  Enamel. — Up  to  a  very  recent  period  our  knowledge 
of  the  phenomena  of  caries  of  the  enamel  has  been  very  meagre. 

Miller,  in  his  earlier  descriptions  of  the  phenomena,  etiology,  and 
morbid  anatomy  of  dental  caries,  did  not  give  a  very  clear  and  distinct 
idea  of  the  modus  operandi  of  caries  in  the  enamel,  but  his  later  sug- 
gestions and  observations,  correctly  interpreted,  led  the  way  to  the  more 
definite  discoveries  of  Williams  in  the  morphology  and  histologic  anatomy 
of  the  enamel,  described  in  Chapter  III.,  Histology  of  the  Dental  Tissues, 
to  which  the  student  is  referred. 

Williams  (1898)  found,  in  studying  enamel  structures,  that  in  decalci- 
fying sections  of  fully  formed  enamel  the  acid  attacks  the  interprismatic 
substance  first,  and  the  rods  fall  apart,  proving  conclusively  that  the  sub- 
stance is  one  which  is  acted  upon  by  acids, — viz.,  calcareous  material,  and 
7iot  an  organic  hasis  substance  composed  of  animal  matter,  but  more  readily 
acted  upon  than  the  enamel-rods  themselves.  If  the  process  of  decalcification 
was  continued,  the  enamel-rods  were  attacked  and  the  whole  structure 
destroyed,  leaving  behind  no  evidence  whatever  of  an  organic  matrix. 

Sections  of  enamel  treated  by  a  one  per  cent,  solution  of  chromic  acid 
—  which  does  not  destroy  organic  substances — left  no  trace  of  organic  ma- 
terial ;  hence  it  can  be  positivefy  stated  that  fully  developed  enamel  con- 
tains not  the  slightest  evidence  of  an  organic  matrix. 

Williams,  in  his  studies  of  caries  of  enamel,  found  zoogloea  masses  of 
micro-organisms  adherent  to  the  surface  of  the  enamel,  probably  attached 
to  the  remains  of  the  enamel  cuticle  and  lining  the  surfaces  of  the  cavities 
of  decay.  He  says,  "Lining  the  cavities  or  covering  the  surface  where 
decay  has  commenced,  there  is  always  to  be  seen  a  thick,  felt-like  mass 
of  acid-forming  micro-organisms.  This  mass  of  fungi  is  so  dense  and 
adhesive  as  to  make  it  highly  improbable  that  the  enamel  is  affected, 


DENTAL    CARIES.  153 

except  in  rare  or  special  instances,  by  any  acid  other  tlian  that  whicli  is 
being  excreted  (lactic)  by  the  bacteria  at  the  very  ]3oint  where  they  are 
attached  to  the  enamel.  This  thick,  glutinous-like  mass  of  fungi  also 
prevents  the  excreted  acid  from  being  washed  away,  so  that  it  exerts  its 
full  chemical  power  upon  calcified  tissue."  This  idea  was  first  suggested 
by  Ficinus  as  far  back  as  1847. 

Dilute  lactic  acid  produced  appearances  upon  sections  of  fully  formed 
enamel  that  were  identical  with  those  produced  upon  this  tissue  in  the 
progress  of  natural  caries. 

Decalcification  of  the  enamel  proceeds  most  rapidly  along  the  line  of 
the  enamel-rods  when  the  process  has  once  been  established.  The  bac- 
teria growing  into  the  spaces  formed  by  the  solution  of  the  interprismatic 
cement  substance  cause  fracture  and  dislodgement  of  masses  of  partially 
decalcified  enamel-rods,  and  thus  hasten  the  process  of  cavity  formation. 

In  cases  of  rapid  caries,  Williams  found  streptococci  almost  always 
present,  while  in  caries  of  slow  progress  ("backward  decay")  the  large 
cocci  and  diplococci  were  always  found.  In  the  direct  caries  of  enamel 
the  cavities  are  lined  with  leptothrix  and  thread-like  forms. 

The  leptothrix  Buccalis  maxima  and  the  bacillus  Buccalis  maximus  of 
Miller  are  nearly  always  found,  the  latter  more  sparingly. 

Beneath  the  felt-like  masses  of  thread-forms,  and  lying  in  contact  with 
the  decomposing  enamel  in  direct  decay,  and  also  in  deep  cracks  and  fis- 
sures in  backward  decay,  there  is  invariably  found  a  short,  thick  bacillus, 
usually  constricted  in  the  centre. 

Williams  suggests  that  possibly  the  variety  of  the  organism  found  in 
these  forms  of  enamel  decay  may  be  the  governing  factors  in  the  rapidity 
of  the  progress  with  which  dissolution  of  the  enamel  takes  place. 

In  the  light  of  these  discoveries  it  may  be  stated  with  certainty  that 
the  first  stage  of  dental  decay  is  characterized  by  a  softening  of  the 
enamel,  which  is  brought  about  as  a  direct  result  of  the  presence  of  carbo- 
hydrates which  undergo  fermentation  through  the  action  of  certain  zymo- 
genic bacteria,  and  that  these  organisms  are  retained  in  protected  positions 
through  the  formation  of  a  gelatin-like  substance  secreted  by  themselves 
or  certain  other  organisms  present  in  the  mouth,  thus  forming  zoogloea 
masses  which  adhere  to  or  become  glued  to  the  surfaces  of  the  teeth. 

By  this  means  the  acid  formed  by  the  zymogenic  organisms  are  kept  in 
contact  with  the  enamel  and  prevented  from  being  washed  away,  as  would 
undoubtedly  be  the  case  were  it  not  for  the  presence  of  this  protecting 
envelope,  thus  permitting  the  full  chemical  action  of  the  acid  upon  the 
enamel  to  go  on  undisturbed. 

Caries  of  Dentin. — In  studying  the  etiology  of  dental  caries  we  have 
found  that  the  same  acid-jDroducing  ferments  or  micro-organisms  were 
accountable  for  the  production,  initiation,  and  i^rogress  of  the  disease  in 
all  of  the  calcified  tissues  of  the  teeth,  and  that  the  saprogenic  bacteria, 
or  possibly  the  same  zymogenic  organisms,  liquefied  the  basis  substance 
and  removed  it,  thus  causing  a  gradual  dissolution  of  these  tissues  until 
the  entire  organ  is  destroyed. 

The  lactic-acid-producing  organisms  belong  to  the  facultative  variety  of 


154  OPERATIVE    DENTISTRY. 

bacteria.  This  lias  been  proved  by  the  fact  that  they  grow  and  develop 
equally  well  upon  the  surface  of  the  enamel  wherever  lodgement  can  be 
found,  in  the  presence  of  the  oxygen  of  the  atmosphere,  and  in  the  tubuli 
of  the  dentin  in  which  th(i  oxygen  of  the  atmosphere  would  be  excluded 
by  the  presence  of  the  fluids  of  the  mouth. 

This  fact  explains  the  progress  of  caries  which  occasionally  occurs 
under  fillings  having  perfect  margins,  in  which,  for  reasons  that  have 
seemed  good  to  the  operator,  portions  of  decalcified  dentin  have  been  per- 
mitted to  remain  in  the  bottom  of  the  cavity,  but  have  not  been  thoroughly 
sterilized  by  dehydration  and  antiseptics. 

For  the  growth  of  micro-organisms  three  conditions  are  absolutely  neces- 
sary,— heat^  moisture,  and  a  proper  soil  or  food-supply  ;  cut  off  any  one  of 
these  and  the  organism  will  cease  to  develop. 

The  permanent  arrest  of  caries,  therefore,  from  the  therapeutic  stand- 
point, sums  itself  up  into,  first,  so  preparing  a  carious  cavity  that  the  food- 
supply  of  the  micro-organisms  and  the  decalcified  tissue  is  thoroughly 
removed,  and,  secondly^  in  so  inserting  a  plug  or  filling  as  to  hermetically 
seal  it. 

Without  the  ingress  of  moisture,  or  the  presence  of  the  elements  from 
which  the  bacteria  elaborate  lactic  acid,  the  progress  of  the  disease  must 
be  arrested. 

Susceptibility  and  Immunity. — Susceptibility  to  caries  has  gener- 
ally been  considered  to  be  one  of  local  environment,  dependent  upon  the 
structural  defects  of  the  enamel  and  dentin  and  conditions  which  favored 
the  development  of  the  lactic-acid-producing  micro-organisms.  While 
immunity  has  been  thought  to  be  the  result  of  perfectly  developed  dental 
tissues  and  conditions  which  retarded  or  prevented  the  formation  of  lactic 
acid,  the  degree  of  suscei3tibility,  it  was  thought,  was  governed  by  the 
extent  of  the  structural  defects  and  the  numbers  and  rapidity  of  develop- 
ment of  the  micro-organisms  of  decay. 

The  investigations  of  Black  (Dental  Cosmos,  May,  1895)  and  of  Wil- 
liams (Dental  Cosmos,  March  and  April,  1897)  have  conclusively  shown 
that  dental  caries  is  not  dependent  upon  the  structural  defects  or  imperfec- 
tions of  the  dental  tissues  nor  to  their  degree  of  calcification. 

Black  determined  by  laborious  and  painstaking  laboratory  experimen- 
tation that  human  teeth  show  wide  difierences  in  physical  structure  of 
both  the  dentin  and  the  enamel,  ranging  from  that  in  which  the  enamel  is 
practically  perfect  in  all  of  its  parts  to  those  which  present  grave  imper- 
fections of  its  physical  structure,  such  as  imperfectly  closed  developmental 
grooves,  which  leave  fissures,  pits,  and  openings  of  various  sizes  and 
shapes. 

The  dentin  also  presents  marked  deviations  from  a  physical  perfection 
of  structure.  In  some  instances  the  dentin  is  very  perfect,  in  others  the 
interglobular  spaces  are  exceedingly  numerous  and  the  granular  areas 
IDresent  many  physical  imperfections. 

These  investigators  have  both  shown  that  these  physical  imperfections 
are  in  no  wise  a  cause  of  dental  caries,  for  among  persons  wholly  immune 
to  caries  these  imperfections  are  relatively  as  frequent  as  in  those  persons 


DENTAL    CARIES.  155 

who  suffer  from  caries,  and  that  even  when  the  imperfections  of  the 
enamel  are  such  as  to  expose  the  dentin,  no  decay  has  occurred  in  a  life- 
time, as,  for  instance,  in  the  imperfections  of  structure  due  to  inherited 
syphilis  and  arrests  of  development  caused  by  the  exanthematous  disease 
of  early  childhood,  etc. 

Black  *  thinks  these  facts  prove  beyond  a  doubt  that  structural  imper- 
fections, at  most,  only  give  greater  oiDportuuity  for  the  active  agents  of 
caries  to  do  their  work,  and  have  no  further  relation  to  that  cause.  In 
other  words,  physical  imperfections  of  the  enamel  and  dentin  are  simply 
local  predisposing  causes  of  the  disease. 

Teeth,  therefore,  which  present  the  most  faulty  structure  may  not 
decay,  and  will  not  decay  in  persons  who  are  immune  to  caries,  while 
teeth  of  the  most  perfect  physical  structure  will  succumb  to  caries  in 
persons  who  are  at  the  time  susceptible  to  the  disease. 

The  active  agents  of  caries  are  to  be  found  in  every  mouth,  and  in 
sufficient  quantities  to  produce  the  disease,  and  yet  in  certain  individuals 
there  is  a  complete  immunity  through  a  lifetime,  while  in  others  there 
may  be  various  periods  of  susceptibility  and  immunity  which  seem  to 
have  no  discovered  relation  to  the  local  environment  or  condition  of  the 
health. 

The  formation  of  the  gelatinous  plaques  or  zooglea  masses  by  the  caries 
fungus,  as  shown  by  Williams  to  be  necessary  to  start  the  i)rocess  of  caries 
in  the  enamel,  are  not  found  in  all  mouths,  though  the  organisms  may  be 
there  and  growing.  The  power  of  the  organism  to  form  gelatin,  according 
to  Black,  seems  to  depend  upon  something  in  the  saliva,  the  nature  of  which 
has  not  been  discovered.  These  facts  seem  to  throw  some  light  upon  the 
subject  by  indicating  the  direction  in  which  future  investigation  should 
proceed. 

At  the  risk  of  being  considered  over-sanguine,  the  writer  suggests  that 
a  means  of  preventing  caries  will  yet  be  discovered,  and  that  it  will  be- in 
the  nature  of  an  antagonist  to  those  organisms  which  have  the  power  of 
forming  gelatin  in  the  oral  fluids. 

Black  is  of  the  opinion  that  susceptibility  is  influenced  by  an  inherited 
predisposition  to  the  loss  of  the  teeth,  or  of  especial  teeth  at  certain  ages  ; 
by  changes  of  environment,  either  of  climate  or  mode  of  life  ;  by  the  age 
of  the  individual,  the  young  being  most  susceptible,  while  immunity 
usually  comes  with  adult  age  ;  and  by  the  fluctuations  of  bodily  conditions 
which  change  the  character  of  the  oral  secretions. 

Phenomena  of  Caries  of  Dentin. — The  invasion  of  the  dental  tis- 
sues by  caries  begins  by  the  decalcification  of  the  enamel,  either  in  some 
fissure,  pit,  or  crack,  which  may  be  only  microscopic  in  size,  or  upon 
roughened  surfaces  which  have  given  lodgement  and  protection  to  the 
zymogenic  organisms,  most  commonly  the  approximal,  labial,  and  buccal 
surfaces,  as  shown  in  Fig.  272, 

The  margins  of  the  cavity  usually  present  more  or  less  discoloration 
or  opacity,  while  the  enamel  will  be  found  softened  by  decalcification  and 

*  Dental  Cosmos,  September,  1899. 


156  OPERATIVE    DENTISTRY. 

broken  down.  Sections  of  teeth  cut  throiigli  a  cavity  of  decay  in  tlie 
enamel  show  immediateh'  beneath  an  exposure  of  the  dentin  with  soften- 
ing and  discoloration.  Closer  inspection  reveals,  lying  between  the  floor 
of  the  cavity  and  the  pulp-chamber,  several  x)eculiarities  in  the  color,  the 
degree  of  decalcification,  the  transmission  of  light,  and  certain  changes  in 
the  size  and  form  of  the  tubuli. 

Pigmentation. — The  color  in  ordinary  caries  at  the  surface  of  the 
cavity  is  yellowish  brown,  but  it  shades  off  as  it  reaches  towards  the  pulp 
into  the  normal  color  of  the  dentin.  In  caries  of  rapid  progress  the  color 
is  white  or  yellowish  white,  while  in  caries  of  slow  progress,  or  in  arrested 
caries,  the  color  is  dark  brown  or  black.  The  more  rapid  the  progress  of  caries 
the  lighter  the  pigmentation.  It  was  thought  at  one  time  that  the  color  was  pro- 
duced by  the  carious  process  or  by  the  micro-organisms.  The  fact,  how- 
ever, that  the  discoloration  can  be  easih'  and  perfectly  reproduced  out  of 
the  mouth,  with  teeth  which  have  been  acted  upon  to  any  considerable 
extent  by  acids,  proves  conclusively  that  it  is  not  due  to  the  process  of 
caries  nor  to  bacteria.  To  accomplish  this.  j)lace  such  teeth  in  water 
holding  in  solution  a  small  quantity  of  sulphuretted  hydrogen,  fill  the 
vessel,  and  place  it  in  a  dark  closet  to  prevent  decomposition  of  the  solu- 
tion, and  the  tissues  of  the  teeth,  to  a  point  as  deep  as  that  affected  by 
the  acid,  will  gradually  assume  a  dark  color.     (Black.) 

Decalcification. — The  degree  of  decalcification  grows  less  and  less 
from  the  surface  of  a  carious  cavity  until  normal  dentin  is  reached.  (See 
Fig.  273.) 

The  outermost  layers  of  the  dentin  will  generally  be  found  completely 
decalcified,  the  basis  substance  being  soft  and  leathery,  and  having  an 
odor  like  that  of  gangrenous  lung-tissue. 

Beyond  the  line  of  jjartial  decalcification  is  a  transparent  zone  known 
as  the  zone  of  Tomes  (Fig.  274),  which  its  discoverer  and  Magitot  have 
maintained  was  caused  by  vital  action,  or  resistance  of  the  tissue  to  the 
encroachment  of  the  disease,  and  produced  by  the  filling  up  of  the  den- 
tinal tubuli  with  calcific  material,  and  thus  making  it  more  easily  j^ene- 
trated  by  rays  of  light.  It  is  in  appearance  very  similar,  both  macrosco^^i- 
caliy  and  microscopically,  to  the  senile  dentin,  the  dentin  of  the  crowns 
of  teeth  worn  down  by  mechanical  abrasion,  and  the  roots  of  teeth  which 
liave  remained  long  in  the  mouth  without  dental  decay. 

Miller,  by  quantitative  analysis,  has  shown  that  it  contains  more 
calcium  salts  than  the  surrounding  normal  dentin.  AValkhoff  thinks  that 
it  is  an  evidence  of  vital  or  formative  activity  induced  by  the  stimulation 
of  irritation,  causing  the  j)roduction  of  an  intercellulai"  substance  at  the 
surface  of  the  cells  and  xjrimarily  of  their  oifshoots. 

It  will  be  noticed,  also,  as  i^ointed  out  by  Gysi,  that  the  transparent 
zone  which  lies  between  the  carious  dentin  and  the  pulp  is  continuous 
with  a  new  formation  of  dentin— secondary  dentin — upon  the  wall  of  the 
pulp-chamber  (Fig.  275). 

Burchard  thinks  "these  evidences  point  to  the  truth  of  Walkhoff's  • 
explanation  of  the  process,  and  indicate  that  the  transparent  appearance 
is  the  result  of  vital  reaction."' 


Fig.  272.— Vertical  section  of  deciduous  molar,  showing  caries  of  enamel  which  started  in  a  fissure,  and 
of  the  dentin  which  had  its  origin  in  an  approximal  cavity  of  decay,     x  8. 


Fig.  273. — Carious  dentin  from  base  (jf  cavity.     (V.  A.  Latham.)     ,     4il.t;i;.     ^l,  infected  tubules;  B,  en- 
larged tubules  ;  C,  infected  interglobular  spaces. 


Fig.  274. — Undermining  caries  of  enamel,  showing  transparent  zone  of  Tomes  at  A.     (R.  R.  Andrews.) 


Ik  t 


Fig.  276. — Dentinal  tubules  from  infected  dentin,  showing  enlargement  of  the  tubules  and  the 
presence  of  micro-organisms  within  them.    (Tomes.) 


DENTAL    CARIES. 


157 


It  is  still,  however,  an  open  question  as  to  whether  the  transparent 
zone  is  or  is  not  a  real  zone  of  resistance  to  the  encroachment  of  the  dis- 
ease and  effective  in  retarding  its  progress.     Clinical  observation  and  ex- 


FiG.  275. 


Longitudinal  ground-section  of  crown  of  an  inferior  molar  of  a  negro.  This  figure  is  drawn  from  a 
ground  and  polished  section  mounted  in  Canada  balsam.  (Gysi.)  E,  enamel ;  D,  dentin  ;  C,  cement ;  p, 
pulp-chamber;  a,  large  decay,  from  the  grinding  surface;  6,  small  decay,  from  the  mesial  surface ;  cs, 
7one  of  septic  invasion  and  discoloration;  e,  partially  decalcified  and  discolored  enamel  around  the 
carious  cavity  ;  z,  dark  zones ;  s',  clearer  zones  ;  z'p,  oldest  zones,  where  putrefaction  of  the  tooth- 
cartilage  begins  ;  c,  outer  transparent  zone,  or  zone  of  Tomes  ;  sd,  secondary  dentin,  caused  by  irritation  ; 
s'd',  secondary  dentin  deposited  by  normal  physiological  process,  recession  of  the  pulp. 


perience  would  seem  to  indicate  that  it  has  an  effect  upon  the  dentin 
which  renders  it  more  resistant  to  the  progress  of  the  disease. 

Expansion  of  the  Tubuli. — Sections  of  carious  dentin  cut  parallel 
with  the  long  axis  of  the  tubuli,  which  have  been  stained  with  fuchsin  or 


158 


OPERATIVE    DENTISTRY 


gentian  violet,  show  these  tubules  to  be  considerably  enlarged,  with  swell- 
ings or  molecular  expansions  upon  individual  tubes  (Fig.  276). 


Fig.  277. 


Fig.  278. 


Fig.  279. 
8^ 


si-s 


a 


\ 


f^ 


Single  tubule  filled  with  cocci. 
(Miller.)  1100:1. 


Fig.  280. 


Decayed  dentin,  showing 
a  mixed  infection  with  cocci 
and  bacilli.    (Miller.)    400:1. 


Single  tubule  filled  with  rods.         Single  tubule  showing  a  mixed 
(Miller.)    1100:1.  infection    with    a    pleomorphous 

bacterium.    (Miller.)    1100:1. 


et 


Fig.  281. 


Longitudinal  section  of  decayed  dentin,  showing  infection  with 
rod-  and  thread-forms.  (Miller.)  a,  tubule  distended,  but  walls 
still  comparatively  intact ;  6,  d,  tubular  walls  broken  through  and 
the  dentin  in  a  state  of  complete  dissolution ;  c,  tubules  out  of  focus. 
Circa  500 : 1. 


There  is,  however,  no  uniformity  in  the  enlargement  of  the  tubules  or 
of  the  nodular  expansions.     Some  tubules  will  be  very  much  enlarged, 


Fig.  282.— Vertical  section  of  infected  human  dentin,  showing  the  presence  of  micro-organisms  and 
enlargement  of  the  tubules.    (K.  E.  Andrews.) 


^f'  ' 


Fig.  283.— Transverse  section  of  infected  human  dentin,  showing  the  presence  of  micro-organisms  and 
various  enlargements  of  the  tubules.     (R.  R.  Andrews.) 


Fig.  284. — Vertical  section  of  infected  human  dentin,  showing  tubules  greatly  enlarged  and  filled  with 
micro-organisms.     (R.  R.  Andrews.) 


Fig.  285. — Infected  human  dentin,  showing  confluence  of  enlarged  tubules  forming  cavities  which  are 
filled  with  micro-organisms.     (R.  R.  Andrews.) 


Fig.  286.— Oblique  se(;tiou  of  infected  human  dentin,  showing  confluence  of  tubules  forming  larger 

cavities.     (R.  R.  Andrews.) 


Fig.  2,87.— Infected  human  dentin,  showing  advanced  state  of  infection.  (V.  A.  Latham.)  :<  100. 
A,  A,  A,  micro-organisms  in  the  tubuli.  The  dark  portion  shows  decalcified  and  discolored  areas  of 
dentin. 


i--^ 


Fig.  288.— Transverse  section  of  human  dentin,  sliowing  pipe-stem  appearance  of  infected  dentinal 

tubules.     (Tomes. ) 


Fig.  289.— Transverse  section  of  dentinal  tubules.     (V.  A.  Latham.)     X  1G2.5.     The  dark  tubules  show- 
infection  with  micro-organisms  and  the  pipe-stem  appearance  described  by  Tomes. 


DENTAL    CARIES.  159 

while  others  will  seem  to  be  only  slightly  affected.  "Walkhoff  declares  the 
dentinal  tubuli  are  regularly  enlarged,  and  that  the  varicosities  appearing 
at  irregular  intervals  are  occasioned  by  the  drying  of  the  specimen. 

Upon  further  examination  with  higher  powers  of  the  microscope  it  will 
be  discovered  that  the  tubuli  in  the  superficial,  softened^  and  decalcified 
dentin  are  filled  with  bacterial  forms,  cocci,  rods,  and  threads,  the  coccus 
forms  predominating. 

Fig.  277  shows  a  single  tubule  filled  with  cocci;  Fig.  278,  one  filled  with 
rods.  Fig.  279  shows  a  mixed  infection  of  cocci,  diplococci,  short  and 
long  rods,  or  infection  with  a  pleomorphous  bacterium  (polymorphous). 
Fig.  280  shows  several  tubules  in  decaying  dentin  filled  with  a  mixed  in- 
fection of  cocci  and  bacilli,  while  Fig.  281  shows  a  longitudinal  section  of 
decayed  dentin  which  is  infected  with  rod-  and  thread-forms.  Figs.  282, 
283,  284,  285,  286,  and  287  show  the  micro-organisms  as  they  appear  in 
slides  made  from  decaying  dentin. 

In  the  deeper  layers  of  decalcified  dentin  the  bacteria  become  less  and 
less  in  numbers,  until  they  finally  disappear.  Beyond  this  non-infected 
point,  however,  there  is  a  zone  of  partially  decalcified  dentin,  the  removal 
of  the  lime-salts  being  caused  by  the  solvent  action  of  the  lactic  acid  pro- 
duced by  the  bacteria  lodged  within  the  tubules. 

Cross-sections  of  decaying  dentin  exhibit  a  very  peculiar  appearance 
of  the  dentinal  tubuli,  or  rather  of  the  sheaths  of  Xeumann  (Fig.  288), 
which  are,  according  to  Tomes,  greatly  thickened,  and  the  lumen  partially 
obliterated,  giving  the  section  the  appearance  of  having  been  built  up  of  a 
multitude  of  tobacco-pipe-stems  (Fig.  289).  Such  is  the  condition  at  a 
certain  stage  of  their  disorganization. 

In  longitudinal  sections  examined  at  a  later  period  the  sheaths  appear 
to  break  up  into  short  lengths  or  sections,  and  are  found  twisted ;  and^ 
finally,  the  whole  tissue  undergoes  disorganization  into  minute  granules, 
which  are  by  degrees  washed  away  by  the  fluids  of  the  mouth. 

Disorganization  of  the  Dentinal  Fibres.— The  contents  of  the 
tubuli — Tomes  fibres — also  appear  to  undergo  disorganization  and  break 
up  into  pipe-stem  sections  or  short  rods  (Fig.  290).  This  was  first  noticed 
by  Tomes. 

This  peculiar  api)earance  has  not  been  satisfactorily  explained.  Tomes 
says,  "These  rods  may  be  portions  of  consolidated  fibrils,  or  they  may  be 
bits  of  the  sheaths  of  ISTeumann,  or  they  may  be  mere  casts  of  the  enlarged 
tubules." 

Wedl,  however,  thinks  the  statement  that  they  are  consolidated  fibrils 
is  not  proved.  Miller  is  of  the  opinion  that  they  are  calcified  fibrils,  as 
he  has  observed  their  rapid  disappearance  while  viewing  them  under  the 
microscope  when  the  siDCcimen  was  treated  with  dilute  sulphuric  acid. 

Another  peculiarity  is  also  observed  in  the  dentinal  tubuli  in  the  form 
of  shining  or  glistening  granules.  These  are  seen  occurring  in  the  early 
stage  of  caries,  and  sometimes  in  the  zone  just  in  advance  of  the  carious 
process.  Some  observers,  Tomes,  Magitot,  and  others,  have  thought  them 
to  be  lime  formations  thrown  out  by  the  odontoblasts  for  the  purpose  of 
resisting  the  advance  of  the  disease.     Wedl,  Black,  and  others  looked 


160  OPERATIVE    DENTISTRY. 

upon  them  as  fat-globules.  Baume  has  shown  conclusively,  however,  that 
these  globules  are  not  particles  of  fat,  since  they  do  not  disappear  when 
treated  with  sulphuric  ether. 

Miller  thinks  these  granular  bodies  cannot  be  lime  formations  thrown 
out  by  the  pulp,  for  they  are  found  in  caries  of  pulpless  as  well  as  living 
teeth,  but  regards  it  as  not  improbable  that  they  have  the  same  origin  as 
the  rod-shaped  (pipe-stem)  formations  found  in  the  tubuli. 

PENETRATION   OF   CARIES. 

Generally  speaking,  the  line  of  progress  or  penetration  of  caries  may  be 
stated  to  be  in  the  direction  of  the  tubuli,  or,  in  other  words,  from  the 
surface  towards  the  pulp.  This,  however,  is  not  universally  the  case,  for 
occasionally  cavities  will  be  found  which  have  been  formed  in  a  direction 
transverse  to  the  tubuli.  The  conditions  which  favor  the  formation  of 
such  cavities  are  usually,  if  not  always,  due  to  faulty  formation  of  the  den- 
tin, interglobular  spaces,  thick  granular  layer,  or  other  imperfections  in  the 
deposition  of  the  calcoglobulin  and  its  calcification.  Such  spaces  offer 
admirable  facilities  for  the  penetration  and  growth  of  the  micro-organisms 
and  the  lateral  extension  of  the  disease.  Fig.  291  shows  interglobular 
spaces  filled  with  micro-organisms.  In  the  ordinary  form  of  caries  the 
disease  travels  along  the  tubules  by  the  penetration  of  the  fungi  into  these 
open  siDaces  (Figs.  292  and  293),  and  exposure  of  the  pulp  takes  place 
before  lateral  spreading  has  progressed  to  any  great  extent.  This  is  espe- 
cially true  of  teeth  of  the  best  development,  for  observation  proves  that 
exposure  of  the  pulp  will  occur  in  this  class  of  teeth  with  the  least  destruc- 
tion of  tissue.  ''The  more  perfect  the  development  the  more  completely 
will  the  penetration  be  confined  to  the  direction  of  the  tubules."    (Black.) 

CARIES   OF   CEMENTUM, 

The  etiology  of  caries  of  cementum  is  so  nearly  like  that  of  decay  of 
dentin  that  it  hardly  needs  a  special  description,  except  that  which  grows 
out  of  the  difference  in  the  histologic  structure.  Decalcification  is  caused 
by  the  same  micro-organisms  that  produce  caries  of  dentin.  The  fungi  first 
attack  the  calcified  rods  known  as  Sharpey's  fibres,  and  penetrate  to  the 
cement- corpuscles  and  their  canaliculi,  decalcifying  the  surrounding  tissue 
as  in  decay  of  dentin.  The  organic  substance  is  then  liquefied  by  the 
saprophytic  bacteria  and  washed  away. 


Fig.  290. — Longitudinal  section  of  infected  human  dentin,  showing  the  pipe-stem  appearance  of  the 
tubules  described  by  Tomes.     (R.  JR.  Andrews.) 


Fig.  291.— Infected  human  dentin.     (V.  A.  Latham.)     X  162.5.     A,  micro-organisms  in  the  tubuli; 
B,  B,  micro-organisms  in  the  interglobular  spaces. 


A 


Fig.  292. — Infected  human  dentin.    (R.  R.  Andrews.)    A,  A,  A,  showing  penetration  of  micro-organisms 

in  the  tubuli. 


Fig.  293. — Infected  human  dentin.     (R.  R.  Andrews.)    A,  A,  showing  penetration  of  micro-organisms 

in  the  tubuli. 


CHAPTER    IX. 

DENTAL   CARIES    (CONTINUED). 

Varieties  of  Caries. — The  older  writers  were  in  tlie  habit  of  dividing 
caries  into  several  varieties,  according  to  the  physical  signs  presented  bj^ 
the  disease,  believing  that  these  signs  represented  distinct  forms  of  the 
affection,  which  they  classified  as  follows :  caries  humida,  moist  caries ; 
caries  acuta,  acute  or  rapid  caries  ;  caries  chronica,  chronic  or  slow  caries  ; 
and  cajHes  sicca,  dry  caries  or  arrested  caries.  This  classification  of  the 
disease  is  no  longer  used,  as  the  aifection  is  now  known  to  be  one  and  the 
same  from  beginning  to  end,  the  differences  in  the  physical  signs  being 
due  to  the  differences  in  the  character  or  perfection  of  the  structure  of  the 
teeth,  the  conditions  of  the  general  health,  the  character  of  the  oral  secre- 
tions, and  the  hygienic  conditions  which  prevail  in  the  mouth.  All  of 
these  factors  have  an  influence  upon  the  extent  and  the  rapidity  in  the 
progress  of  the  disease,  and  are  responsible  for  the  differences  in  the 
physical  signs. 

Stages  of  Caries. — It  is  customary  with  most  writers  in  describing 
dental  caries  to  divide  the  disease  into  various  natural  periods  or  stages. 
Magitot  divided  the  affection  into  three  periods,— first,  second,  and  tfih^d. 

The  first  period  he  confined  to  the  dissolution  of  the  enamel.  The 
second  period  to  the  destruction  of  the  dentin.  The  third  period  to  the  in- 
volvement of  the  pulp-chamber. 

A  more  exact  division  of  the  stages  of  the  disease  recognizes  four  dis- 
tinct periods  or  degrees  of  progression  : 

First,  superficial  or  incipient. 

Second,  progressive. 

TJiird,  deep-seated. 

Fourth,  complicated. 

In  the  first,  or  superficial  or  incipient,  stage  (Fig.  294,  A)  the  disease  in- 
volves only  the  enamel  or  the  cementum.  This  may  be  confined  to  the 
surface  of  these  tissues  or  involve  their  whole  thickness,  forming  a  per- 
ceptible cavity,  which  may  be  more  or  less  sensitive  to  sweets,  acids,  or 
thermal  changes. 

In  the  second,  or  progressive,  stage  (Fig.  294,  B)  the  enamel  or  the  cemen- 
tum has  been  penetrated  and  the  disease  is  extending  into  the  dentin, 
forming  a  deeper  cavity. 

The  third,  or  deep-seated,  stage  (Fig.  294,  G)  represents  a  more  serious 
involvement  of  the  dentin,  reaching  almost  to  the  pulp-chamber  ;  not,  how- 
ever, exposing  the  pulp,  but  causing  irritation  and  making  it  necessary  to 
protect  it  by  some  form  of  capping  before  inserting  a  filling. 

In  the  fourth,  or  complicated,  stage  (Fig.  294,  D)  the  disease  has  extended 
to  the  pulp-chamber,  causing  inflammation  or  death  of  the  pulp. 

The  rapidity  with  which  caries  sometimes  progresses  often  makes  it 

11  161 


162 


OPERATIVE    DENTISTRY. 


Fig.  294. 


Vertical  section  of  a  lower 
molar  tooth  showing  stages  of 
caries. 


impossible  to  distinguish  the  various  stages  one  from  another,  while  in 
such  cases  especially  there  is  a  lack  of  j)igmentation.  This  form  of  the 
disease,  which  is  sometimes  termed  icMte  decay  (caries  humida),  not  infre- 
quently in  the  course  of  a  few  weeks  destroys  one-half  or  more  of  the 
tooth  and  exi)oses  the  pulp.  In  the  ordinary  form  of  caries  (caries  acuta), 
sometimes  designated  as  hroxon  decay,  the  time  required  for  the  disease  to 

penetrate  from  the  enamel  to  the  pulp- chamber 
is  from  six  to  eighteen  months,  while  in  that 
form  known  as  hlack  decay  (caries  chronica)  the 
process  is  so  slow  that  several  years  are  required 
for  the  disease  to  penetrate  to  the  pulp. 

Symptoms. — The  symptoms  of  caries  in  its 
earlier  stages  vary  from  a  mild  drawing  or  gnaw- 
ing sensation  to  that  of  acute  pain.  These  symp- 
toms are  induced  by  the  exposure  of  the  dentinal 
fibrils  to  the  irritating  effects  of  sweets,  acids, 
salt,  changes  of  the  temperature,  and  instrumen- 
tation. 

The  character  and  severity  of  the  symptoms 
vary  with  different  individuals,  and  in  the  same 
individual  at  different  times  and  under  varying 
circumstances. 

Temperament  has  much  to  do  with  the  char- 
acter and  severity  of  the  pain  experienced  by  people  suffering  from  dental 
caries.  Individuals  possessed  of  exalted  nervous  irritability  suffer  much 
more  than  others,  while  in  the  same  individuals  certain  conditions  of 
health,  like  anaemia,  dyspepsia,  nervous  prostration,  mental  worry,  or 
other  causes  which  depress  the  vital  forces,  as  chlorosis  and  pregnancy, 
often  greatly  increase  the  susceptibility  to  pain  and  render  the  symptoms 
of  caries  very  acute. 

It  is  also  a  notable  fact  that  many  times  in  the  first  and  second  stages  of 
the  disease  there  will  be  great  sensitiveness  of  the  dental  tissues,  but  as 
the  process  advances  the  sensitiveness  diminishes  until  the  pulp  becomes 
involved . 

Under  ordinary  circumstances  the  superficial  layers  of  carious  dentin 
are  much  more  sensitive  than  those  which  lie  deeper.  This  is  also  true  of 
normal  dentin.  The  peripheral  extremities  of  the  dentinal  fibrillte,  or  that 
portion  of  them  which  lies  directly  beneath  the  enamel  and  cementum, 
assuming  that  the  fibilllse  carry  sensation,  are  much  more  sensitive  than 
at  their  deeper  parts.  This  is  true  of  peripheral  nerves  everywhere.  The 
irritation  attendant  upon  the  carious  process  greatly  increases  the  sensi- 
tiveness of  the  fibrilljB,  and  produces  what  is  termed  hypersensitwe  dentin. 
In  certain  individuals,  however,  the  sensitiveness  of  their  teeth  is  so  slight 
that  carious  cavities  can  be  excavated  with  little  or  no  pain  so  long  as  the 
pulp  is  not  invaded,  the  character  or  rapidity  of  the  carious  process  seem- 
ingly making  no  difference. 

And  yet  some  of  these  individuals  would  be  classed  as  possessing  the 
temperament  known  as  nervous,  while  others  would  be  classed  as  sanguine, 


DENTAL    CARIES.        -  163 

bilious,  and  lymphatic.  Does  this  lack  of  irritability  to  stimuli,  applied  to 
the  dentinal  fibrillse,  lie  in  the  fibrillge  themselves  or  in  the  general  ner- 
vous system  of  the  individual  1  Or  is  there  some  difference  in  the  char- 
acter of  the  micro-organisms  which  jjroduce  the  disease,  or  in  the  irritating 
quality  of  the  acid  produced  by  them  ? 

These  are  the  questions  which  the  writer  has  often  propounded  to  him- 
self, but  has  never  been  able  to  satisfactorily  answer. 

In  the  third,  or  deep-seated,  stage  of  caries,  severe  pain  is  often  experi- 
enced from  the  entrance  of  irritating  substances  or  their  application  to  the 
diseased  dentin.  When  decalcification  of  the  dentin  has  progressed  to  a 
point  that  reaches  the  pulp,  but  not  exposing  it,  irritating  substances 
having  gained  access  to  the  cavity  of  decay,  often  cause  hypersemia  of  the 
pulp,  and  produce  paroxysms  of  pain  of  a  more  or  less  severe  character, 
lasting  for  a  few  minutes,  or  it  may  be  for  a  much  longer  period.  The  irri- 
tation of  the  pulp  may  be  so  severe  as  to  produce  inflammation  and  death 
of  the  organ. 

The  fourth,  or  complicated,  stage  is  usually  ushered  in  by  pain  of  a  severe 
and  prolonged  character,  from  the  invasion  of  the  pulp- chamber,  which, 
permitting  septic  infection,  causes  inflammation  and  death  of  the  pulp. 

It  often  happens,  however,  that  the  vitality  of  the  pulj)  has  been  de- 
stroyed by  the  irritating  and  septic  conditions  accompanying  the  deep- 
seated  stage  of  the  disease,  and  the  pulp-chamber  will  be  found  to  be  oc- 
cupied by  the  remains  of  a  gangrenous  pulp  ;  or  the  exposure  of  the  pulp 
may  have  resulted  in  a  low  grade  of  suppurative  inflammation  which  has 
become  chronic;  or  inflammation  of  a  chronic  type  may  have  resulted  in 
hypertrophy  of  the  pulp,  which  has  more  or  less  completely  filled  the 
cavity  of  decay. 

Sensitiveness  and  pain,  however,  do  not  always  accompany  the  progress 
of  caries,  even  in  the  latter  stages  of  the  disease,  and  it  is  not  uncommon 
with  certain  individuals  to  find  the  pulp-chamber  invaded  and  the  pulp  in 
a  gangrenous  condition  without  pain  being  experienced  at  any  period  of 
the  carious  process. 

Diagnosis. — The  diagnosis  of  caries  can  usually  be  made  without 
much  trouble,  and  yet  in  some  cases  it  becomes  a  matter  of  considerable 
difficulty.  The  disease  is  to  be  sought  for  in  those  locations  which  expe- 
rience has  taught  the  operator  are  the  most  vulnerable,  and  therefore  the 
most  likely  to  furnish  evidences  of  tissue  disintegration.  These  locations 
have  already  been  indicated  as  found  in  the  enamel  in  the  natural  fissures, 
sulci,  and  pits,  u.pon  the  approximal,  buccal,  and  labial  surfaces,  and  not 
infrequently  in  cracks  caused  by  traumatic  injuries,  and  the  expansion  and 
contraction  of  the  tissue  incident  to  the  great  and  rapid  changes  in  tem- 
perature to  which  they  are  often  subjected  in  going  from  a  warm  room  to 
a  cold  outside  atmosphere,  often  many  degrees  below  zero  ;  or  in  immedi- 
ately following  a  mouthful  of  some  hot  fluid  with  another  one  of  ice- 
water,  a  custom  very  common  among  Americans.  These  imperfections  in 
the  initial  stage  of  the  disease  are  frequently  microscopic  in  size,  but 
are,  nevertheless,  sufliciently  large  to  give  access  to  the  organisms  of 
caries. 


164  OPERATIVE   DENTISTRY, 

The  approximal  surfaces  of  the  teeth  are  the  locations  which  are  most 
often  the  seat  of  caries,  from  the  fact  that  the  inter-appro ximal  spaces  give 
constant  lodgement  for  alimentary  debris^  and  fluids  are  held  by  capillary 
attraction,  thus  favoring  the  processes  of  fermentation. 

The  lingual,  labial,  and  buccal  surfaces  are  most  free  from  the  carious 
process,  and  in  the  order  named,  while  their  most  vulnerable  points  are 
the  developmental  furrows  and  pits  and  the  cervical  margins  at  the  free 
edge  of  the  gums. 

Parreidt  has  ascertained  that  on  an  average  one  hundred  carious  teeth 
would  be  composed  of  twenty-six  incisors  and  cuspids,  twenty-eight  bicus- 
pids, and  forty-six  molars.  Of  the  incisors  and  cuspids,  ninety-eight  per 
cent.,  on  an  average,  decay  on  the  approximal  surfaces,  and  only  four  per 
cent,  on  the  incisive,  lingual,  and  labial  surfaces.  The  bicuspids  decay 
most  frequently  upon  the  approximal  surfaces,  the  percentage  being  ninety- 
two  ;  while  the  molars  decay  most  often  upon  the  morsal  surfaces,  the  per- 
centage being  seventy-two ;  the  approximal  surfaces,  twenty-eight ;  the 
labial  and  lingual,  two.  He  says,  further,  '' According  to  my  observation, 
the  first  appearances  of  caries  occur  in  sixty-four  cases  out  of  one  hundred 
on  the  approximal  surfaces  of  the  teeth."  These  surfaces  are  often  so 
close  together  that  it  is  with  extreme  difficulty  that  the  eye  can  detect  the 
disease  in  its  incipient  stage  without  resorting  to  mechanical  appliances 
for  separation  or  the  use  of  reflected  artificial  light. 

The  most  difficult  cases  to  diagnosticate,  however,  are  those  which  give 
no  evidence  to  the  eye  of  disintegration  of  the  enamel,  but  are  so  far  pro- 
gressed as  to  cause  acute  and  severe  pain.  These  most  often  begin  in  some 
tiny  pit  or  fissure  upon  the  morsal  surface  of  the  molars  and  bicuspids,  or 
the  buccal  surfaces  of  the  molars,  in  which  the  ]Drocess  of  decay  has  been 
so  rapid  and  the  point  of  entrance  of  the  micro-organisms  so  small  that 
there  has  been  no  change  in  the  color  of  the  affected  tissue.  The  discovery 
of  such  cases  calls  for  a  high  degree  of  skill  and  unlimited  patience. 

Many  such  cases  have  been  entirely  overlooked  by  practitioners  of  con- 
summate skill  and  large  experience,  and  diagnosticated  as  neuralgia  or  as 
imaginary  pains. 

Too  much  care  cannot  be  exercised  in  the  examination  and  diagnosis 
of  these  cases,  as  a  failure  to  find  the  cause  often  entails  great  suffering 
upon  the  patient  and  loss  of  reputation  to  the  consultant. 

The  means  which  are  used  in  examinations  of  the  mouth  have  been 
fully  described  in  Chapter  YI. ,  to  which  the  reader  is  referred. 

Prognosis. — The  prognosis  of  dental  caries,  if  no  therapeutical  or  sur- 
gical means  are  introduced  for  its  arrest  or  control,  is,  as  a  rule,  extremelj^ 
bad,  for  nearly  every  tooth  so  attacked  will  be  sooner  or  later  entirely 
destroyed. 

The  prognosis  for  those  teeth  which  are  operated  upon  according  to  the 
most  approved  methods  of  conservation  will  depend  in  large  measure  upon 
the  thoroughness  with  which  these  methods  have  been  applied,  and  the 
care  which  is  afterwards  given  by  the  patient  to  the  hygienic  conditions  of 
the  mouth. 

Eecurrence  of  the  disease  at  the  margins  of  the  filling  after  a  few  years 


DENTAL   CAEIES.  165 

will  invariably  occur  if  the  operation  has  been  faulty,  or  the  patient  has 
been  neglectful  of  the  ordinary  means  of  cleansing  the  teeth  and  preserving 
the  mouth  in  a  healthful  condition. 

The  disease  in  individual  teeth  may  be  arrested  at  any  stage  of  its 
progress^  and  recurrence  prevented,  provided  the  therapeutic  measures 
above  indicated  are  faithfully  followed,  but  the  tendency  to  the  affection 
cannot  be  eradicated  except  by  the  removal  in  toto  of  the  predisposing  and 
exciting  causes. 

Much,  however,  may  be  accomplished  by  the  institution  of  certain  pro- 
phylactic measures,  which  will  be  discussed  in  the  following  chapter. 


CHAPTEE  X. 

TREATMENT  OF  CARIES.   PROPHYLAXIS. 

Definition. — Prophylaxis  (from  the  Greek  ■Kp64>oXa^is,  caution;  tt^oo,  be 
forehand ;   (puXaffaw^  to  guard,  to  prevent).     The  prevention  of  disease  f 
preventive  measures  ;  preventive  medicines  ;  hygiene. 

The  treatment  of  dental  caries  resolves  itself  into  the  application  of 
those  measures  which  aim  at  the  prevention  of  the  disease, — prophylaxis, — 
and  those  which  are  instituted  to  arrest  the  progress  of  the  affection  and 
remedy  the  defects  and  injuries  which  have  been  caused  by  it, — thera- 
peutics. 

Prophylactic  treatment  comprehends  all  of  those  measures  which  are  insti- 
tuted for  the  purpose  of  removing  the  exciting  causes  of  the  disease,  and, 
as  far  as  possible^  rendering  inoperative  those  causes  which  are  predis- 
posing factors. 

The  removal  of  the  exciting  causes  of  dental  caries  should,  from  the 
importance  of  the  subject,  receive  our  first  and  most  earnest  attention.  As 
already  indicated  in  a  previous  chapter,  the  science  of  dental  surgery  has 
not  yet  come  up  to  the  demands  upon  it  in  the  prophylactic  treatment  of 
dental  caries,  and  until  such  time  as  it  does,  the  profession  will  not  be 
fulfilling  its  highest  obligations  to  its  clientele. 

Cleanliness  of  the  mouth  and  teeth  is  the  greatest  of  all  prophylactic  measures 
lohich  can  be  instituted  against  dental  caries.  This  statement  needs  no  verifi- 
cation, for  it  should  be  patent  to  every  one  whose  observation  and  opera- 
tive experience  have  extended  over  even  a  limited  period  of  time,  as  they 
must  have  noticed  how  exceedingly  rare  it  is  for  caries  to  occur  upon 
smooth  surfaces  of  the  teeth  which  are  fully  exposed  to  the  friction  of  foods 
in  mastication  and  the  cleansing  action  of  the  tongue,  lips,  or  cheeks,  and 
the  oral  secretions. 

The  prevention  of  caries,  therefore,  should  aim  at  securing  perfect 
cleanliness  of  the  mouth,  for  this  implies  the  destruction  of  the  zymogenic 
micro-organisms  of  decay,  and  the  removal  of  their  acid  products  and  all 
fermentable  material,  as  well  as  the  correction,  so  far  as  possible,  of  those 
constitutional  conditions  which  lower  the  vitality  and  tend  to  vitiate  the 
oral  secretions. 

The  value  of  perfect  oral  cleanliness  is  not  generally  understood  by 
the  public.  Most  peoj)le  brush  their  teeth  for  purely  cosmetic  reasons, 
and  not  to  prevent  disease.  It  therefore  becomes  the  duty  of  every  dentist 
to  so  instruct  his  clients  in  the  need  of  oral  hygiene  as  a  preventive  measure 
against  disease,  and  the  means  by  which  they  may  .secure  this  condition, 
that  they  will  fully  appreciate  its  value,  and  intelligently  strive  to  carry 
out  the  instruction  in  all  of  its  details.  These  measures  should  con- 
sist of : 

166 


TREATMENT   OF   CARIES.  167 

1.  Instruction  to  parents  in  the  care  of  their  children  in  relation  to 
general  measures  of  hygiene, — food,  clothing,  exercise,  pure  air,  bathing, 
etc., — that  the  best  possible  development  of  the  whole  body,  and  conse- 
quently of  the  dental  organs,  may  be  secured. 

2.  In  such  a  regular  and  systematic  mechanical  cleansing  of  the  teeth 
and  the  mouth  that  the  acid-producing  bacteria  and  the  fermentable  sub- 
stances upon  which  they  grow  may  be  thoroughly  removed  or  reduced  to 
the  minimum. 

3.  By  j)rohibiting  or  so  limiting  the  consumption  of  such  foods  and 
confections  as  furnish  the  material  for  acid  formation  that  the  chief  source 
of  lactic  acid  may  be  eliminated  or  greatly  reduced. 

4.  In  such  a  systematic  and  intelligent  use  of  antiseptics  that  the 
zymogenic  bacteria  may  be  destroyed,  or  their  number  and  action  so 
limited  as  to  render  them  practically  harmless. 

Miller,  in  his  experiments  with  the  zymogenic  bacteria  of  the  mouth 
and  the  influence  of  certain  prophylactic  measures  upon  them,  has  ren- 
dered a  service  to  humanity  which  is  beyond  calculation. 

The  great  value  of  mechanically  cleansing  the  mouth  with  the  brush, 
toothpick,  floss-silk,  etc.,  he  demonstrated  by  taking  ten  cubic  centi- 
metres of  saliva  from  the  mouth  before  cleansing  it,  and  adding  half  a 
gramme  of  starch,  and  placing  the  mixture  in  the  incubator.  After 
cleansing  the  mouth  an  equal  amount  of  saliva  and  starch  were  mixed, 
and,  as  before,  placed  in  the  incubator.  The  flrst  mixture  not  only 
showed  earlier  signs  of  fermentation  than  the  second,  but  also  formed  more 
acid  in  a  given  time.  In  later  experiments  he  determined  the  amount  of 
acid  produced  in  two  equal  infections  from  the  same  individuals  before 
and  after  a  careful  cleansing  of  the  mouth  and  teeth,  and  found  the  amount 
of  acid  produced  by  the  latter  sometimes  as  low  as  one-fourth  that  of 
the  former,  while  after  the  use  of  strong  antiseptic  mouth-washes  the 
amount  was  reduced  to  nil.  ''There  is  no  known  solution,  alkaline  or 
antiseptic,  applicable  in  the  human  mouth,  which  will  penetrate  between 
the  teeth,  or  to  the  bottom  of  fissures  and  cavities, — when  these  are  filled 
with  food, — in  suflBcient  quantity  to  have  any  appreciable  effect.  Therefore 
before  all  antiseptics  or  alkaline  washes  come  the  tooth-brush,  toothpick, 
and  floss-silk." 

Thorough  mechanical  cleansing  of  the  teeth  can  only  be  accomplished 
by  the  use  of  all  these  means.  The  brush  alone,  even  when  used  with  the 
greatest  intelligence,  will  not  thoroughly  remove  the  food  debris  from  the 
inter-approximal  spaces,  and  it  becomes  necessary  to  follow  its  use  with 
the  toothpick,  and  afterwards  with  waxed  floss-silk  drawn  between  the 
teeth,  in  order  to  free  the  proximate  surfaces  of  all  fermentable  substances. 
To  insure  a  perfect  hygienic  condition  of  the  mouth  this  cleansing  j)rocess 
should  be  repeated  after  every  meal,  and  the  mouth  sterilized  with  an 
antiseptic  solution  after  each  cleansing,  on  retiring  at  night  and  upon 
rising  in  the  morning. 

The  importance  of  this  statement  cannot  be  over-estimated  nor  too 
strongly  impressed  upon  those  seeking  the  services  of  the  dental  specialist, 
for  therein  lies  the  salvation  of  the  teeth.     Too  many  people  imagine  that 


168  OPERATIVE    DENTISTRY. 

antiseptic  mouth- washes  are  sufficient  to  correct  the  tendency  to  fermenta- 
tion, regardless  of  the  fact  that  when  food  debris  is  retained  between  the 
teeth  and  in  the  sulci  and  fissures  the  antiseptics  do  not  penetrate  these 
substances,  and  therefore  the  action  of  the  zymogeliic  bacteria  is  only  re- 
tarded upon  the  surfaces,  while  in  the  deeper  portions  it  still  goes  on  with 
unhindered  rajiidity. 

Dentifrices  of  various  composition  are  used  as  adj  uncts  to  the  mechani- 
cal action  of  the  tooth-brush  ;  these  are  made  in  the  form  of  powders, 
pastes,  and  soaj)S. 

Miller  places  no  particular  value  on  tooth-powder  as  a  means  of 
cleansing  the  teeth.  He  admits  that  the  external  surfaces,  particularly  of 
the  front  teeth,  may  be  kept  whiter  by  the  use  of  tooth-powder,  but  thinks 
the  centres  of  decay  are  more  liable  to  become  stopped  up  than  to  be 
cleansed  by  tooth-powder,  particularly  when  they  contain  insoluble  sub- 
stances. 

He  would  recommend  tooth-soaj)S,  in  so  far  as  they  dissolve  fatty  sub- 
stances without  attacking  the  teeth,  and,  furthermore,  possibly  make  the 
penetration  of  the  bristles  of  the  tooth-brush  into  the  centre  of  decay  some- 
what more  easy.  He  thinks  the  dentifrice  should  be  made  of  neutral  soap 
and  have  a  neutral  or  slightly  alkaline  reaction,  and  finally  says,  '^  Under 
all  conditions,  however,  the  chief  thing  is  the  thorough  mechanical 
cleansing  of  the  teeth." 

Tomes  says,  "In  many  respects  tooth-soaj)S  are  to  be  preferred  to 
powders." 

The  writer,  however,  has  never  been  able  to  appreciate  the  advantages 
of  the  tooth-soaps  over  tooth-powders  or  tooth-pastes,  for  there  are  few 
mouths  in  which  the  teeth  can  be  kej)t  bright  and  clean  without  the 
polishing  effect  of  some  form  of  tooth-powder  containing  calcium  carbonate 
or  magnesium  carbonate. 

All  good  tooth-powders  and  pastes  should  contain  a  sufficient  amount 
of  the  best  castile  soap  to  gain  the  advantage  of  its  dissolving  action  upon 
fatty  substances.     The  following  formulae  will  be  found  useful. 

Tooth-powder.  Tooth-paste. 

R  Precipitated  chalk g  viii ;  R   Precipitated  chalk g  viii ; 

Pulv.  orris  root 5  iv  ;  Pul v.  orris  root ,?  iv  ; 

Pulv.  cinchona  bark ^  iv  ;  Pulv.  cinchona  bark g  i v  ; 

Pulv.  cinnamon ^  v  ;  Pulv.  castile  soap 5  ii ; 

Pulv.  castile  soap 5  ii ;  Bicarbonate  of  soda 5  i ; 

Pulv.  white  sugar 5  iv  ;  Oil  of  gaultheria f  3  ss ; 

Oil  of  lemon gtt.  xx  ;  Glycerol,  q.  s.  to  make  a  thick  paste. 

Oil  of  rose gtt.  ii.  Mix,  pulverize,  and  sift  the  dry  ingredients 

Mix,  pulverize,  and    sift  through  a  fine  before  adding  the  oil  of  gaultheria 

hair  sieve.  and  the  glycerol. 

It  is  not  necessary  to  give  more  than  one  or  two  formulae  for  dentifrices, 
as  a  large  variety  of  good  powders,  pastes,  and'  soaps  have  been  placed 
upon  the  market  by  the  dental  dealers,  most  of  which  are  entirely  reli- 
able, and  the  dentist  may  place  them  in  the  hands  of  his  clients  with  con- 
fidence that  they,  are  what  they  are  represented  to  be. 


TEEATMENT   OF   CARIES. 


169 


Miller,  in  his  exxDeriments  with  regard  to  the  effects  of  various  anti- 
septics upon  the  zymogenic  function  of  the  mouth-bacteria,  found  great 
difSiculty  in  selecting  substances  to  which  serious  objections  could  not  be 
raised,  either  from  their  injurious  effects  u^Don  the  teeth  or  the  mucous  mem- 
brane, their  general  toxic  effects,  or  from  their  disagreeable  taste  or  smell. 

The  following  substances,  in  solutions  admissible  for  use  in  the  mouth, 
were  tested  by  him  as  to  the  time  necessary  to  devitalize  bacteria.  Several 
of  them  were  found  to  accomplish  this  result  inside  of  one  minute. 


Antiseptic- 


Salicylic  acid* 

Benzoic  acid* 

Listerine 

Salicj'Iic  acid 

Bichloride  of  mercury 

Benzoic  acid 

Borobenzoic  acid 

Thymol   

Bichloride  of  mercury 

Peroxide  of  hydrogen 

Carbolic  acid 

Oil  of  peppermint  in  agreeable  strength. 

Permanganate  of  potash 

Boric  acid 

Oil  of  wintergreen 

Tincture  of  cinchona 

Lime-water 


Concentration. 


1  to 
1  to 


100 
100 


1  to  200 
1  to  2500 
1  to  200 
1  to  175 
1  to  1500 
1  to  5000 
10  per  cent. 
1  to  100 


1  to  4000 
1  to  50 


Ito   18 


Time  necessary  for 
devitalization. 


I  minute. 
|-  minute. 

1  to  J  minute. 
J  minute. 

2  to  I  minute. 
1  to  2  minutes. 

1  to  2  minutes. 

2  to  4  minutes. 
2  to  5  minutes. 
10  to  15  minutes. 
10  to  15  minutes. 
5  to  10  minutes. 
More  than  15  minutes. 
More  than  15  minutes. 
More  tlTian  15  minutes. 
More  than  15  minutes. 
No  action. 


It  will  appear  that  only  a  very  few  of  these  substances  are  really  ser- 
viceable for  the  purpose  of  disinfecting  the  mouth,  for  the  reason  that  the 
time  necessary  to  destroy  the  vitality  of  the  bacteria  is  too  long.  Solutions 
which  will  not  sterilize  the  oral  cavity  in  from  one  to  two  minutes  would 
possess  little  value  as  antiseptic  mouth-washes,  for  usually  such  solutions 
do  not  remain  in  the  mouth  for  more  than  a  few  seconds,  or  at  most  for  a 
minute. 

According  to  Miller,  '  ^  The  bichloride  of  mercury  is  the  most  active, 
not  only  because  it  has  the  highest  antiseptic  power,  but  because  its  action 
continues  for  a  longer  time." 

Lister,  who  used  it  very  extensively  in  his  surgical  practice  at  one 
time,  has  gone  back  to  carbolic  acid,  for  the  reason  that  a  five  to  ten  per 
cent,  solution  penetrates  the  tissues  to  a  greater  depth  than  a  1  to  500 
solution  of  bichloride  of  mercury.  Strong  bichloride  solutions  coagulate 
the  albumin  upon  the  surface,  and  thus  form  a  barrier  against  the  pene- 
trating effect  of  the  drug. 

Listerine  was  found  by  Miller  to  be  a  very  efficacious  preparation  for 
sterilizing  the  mouth.  It  produced  devitalization  of  mouth- bacteria  in 
from  one-fourth  to  one-half  a  minute.  It  should  be  applied  to  the  tooth- 
brush or  diluted  one-half  as  a  mouth-wash. 


Salicylic  and  benzoic  acids  may  be  apphed  in  this  concentration  only  on  the 


brush. 


170  OPEEATIVE   DENTISTEY. 

Pasteurine,  borolyptol,  thymozone,  and  other  similar  preparations  whicli 
are  combinations  of  benzoic  acid,  thymol,  formalin,  etc.,  are  efficacious  in 
sterilizing  the  mouth,  have  a  favorable  tonic  action  upon  the  soft  tissues, 
and  reduce  inflammation. 

Miller  found  that  the  oil  of  wintergreen  and  other  similar  aromatic 
substances,  which  usually  form  an  important  constituent  of  mouth- washes, 
have,  in  an  adaptable  concentration  for  use  in  the  mouth,  very  little  anti- 
septic action.    He,  however,  excepts  oil  of  peppermint  from  this  category. 

Black  extols  the  antiseptic  qualities  of  oil  of  cassia,  oil  of  cinnamon, 
and  oil  of  cloves,  and  thinks  they  have  a  much  higher  antiseptic  power 
than  oil  of  peppermint. 

Koch,  on  the  other  hand,  found  oil  of  peppermint  to  have  an  anti- 
septic action  nearly  seven  times  as  strong  as  oil  of  cloves.  Miller  thinks 
this  difference  between  these  astute  observers  may  be  accounted  for  in  the 
difference  of  the  bacteria  experimented  upon. 

Thiersch's  antiseptic  solution  the  writer  has  found  to  be  a  most  valuable 
sterilizing  mouth-wash.  It  is  slightly  bitter  to  the  taste,  but  this  may  be 
disguised  by  the  addition  of  a  few  drops  of  oil  of  cassia,  oil  of  pepper- 
mint, or  oil  of  wintergreen. 

The  formula  is  as  follows  :  Salicylic  acid,  four  parts  ;  boric  acid,  twelve 
parts ;  water,  one  thousand  parts.  Flavor  to  suit  the  taste.  It  may  be 
used  ad  libitum. 

The  most  effective  method  of  using  antiseptic  mouth-lotions  is  that 
suggested  by  Ottolengui,  to  force  the  solution  between  the  teeth  and  over 
the  surfaces  by  means  of  an  atomizer. 


CHAPTEE   XL 

TREATMENT   OF   CARIES    (CONTINUED).       MEDICATION.       EXCISION. 

Definition. — Therapeutics  (from  the  Greek  eepaizeoruii^  curative). 
That  branch  of  medical  science  which  considers  the  application  of  reme- 
dies as  a  means  of  cure. 

The  therapeutic  treatment  of  dental  caries  consists  in  the  application 
of  certain  surgical  principles  and  mechanical  procedures  which  are  adapted 
to  the  peculiar  nature  and  causation  of  the  disease,  the  character  of  the 
tissue  affected,  the  extent  and  the  rapidity  of  the  progress  of  the  affection, 
its  complications,  the  environment,  and  the  liability  of  the  disease  to  re- 
currence. 

The  surgical  procedures  which  are  applicable  to  the  cure  of  dental 
caries  are  Medication,  Excision,  and  Obturation  or  Filling. 

MEDICATION. 

Treatment  by  medication  consists  of  impregnating  the  softened  sur- 
face of  enamel  or  dentin  with  nitrate  of  silver  or  some  other  salt  which 
will  destroy  the  bacteria  which  have  penetrated  these  tissues,  and  so  change 
the  character  of  the  impregnated  tissues  that  they  no  longer  offer  a  favor- 
able field  for  the  growth  and  development  of  the  lactic-acid-producing 
fungi. 

The  idea  of  arresting  dental  caries  by  the  application  of  the  nitrate  of 
silver  was  presented  more  than  fifty  years  ago.  It,  however,  never  came 
into  general  use  except  in  the  treatment  of  superficial  caries  in  the  pos- 
terior part  of  the  mouth.  The  great  objection  which  has  been  raised 
against  its  employment  is  the  fact  that  it  stains  the  eroded  enamel  and 
the  exposed  dentin  jet-black,  thus  giving  a  very  unsightly  appearance  to  a 
tooth  so  treated.  If  the  treatment,  however,  has  been  successful,  the  black 
stain  gradually  disappears,  leaving  a  polished  mahogany-brown  surface, 
which  is  immune  to  caries. 

Stebbins  (1891)  revived  interest  in  this  method  of  treatment  by  advo- 
cating its  use  for  the  arrest  of  caries  in  the  temporary  teeth.  The  black- 
ening of  the  decayed  surface  in  these  cases  is  not  so  objectionable  as  in  the 
permanent  teeth,  while  it  often  renders  the  preservation  of  the  deciduous 
teeth  a  much  easier  task  than  by  the  more  difficult,  laborious,  and  painful 
operation  of  inserting  a  filling. 

Stebbins  advocated  the  application  of  a  solution  of  silver  nitrate  to  the 
carious  cavity  by  means  of  a  small  pointed  stick  inserted  in  a  socket  in- 
strument or  porte- carrier  made  for  the  purpose. 

He  found  that  many  cases  needed  no  further  treatment,  as  the  carious 
process  was  completely  arrested,  while  in  others,  after  a  few  months,  a 

171 


172  OPERATIVE    DENTISTRY. 

second  application  was  necessary.  In  many  cases  he  thought  it  advisable 
to  fill  the  cavities  with  gutta-x:>ercha  after  the  application  of  the  silver 
nitrate. 

Peirce  recommends  that  application  be  made  by  means  of  pieces  of 
blotting-paj^er  of  suitable  size,  saturated  in  a  forty  per  cent,  solution  of 
the  drug,  and  kept  ready  for  use. 

Kirk  objects  to  the  use  of  blotting-paper  or  cotton  as  a  means  of  apply- 
ing the  solution,  for  the  reason  that  ^'the  contact  of  silver  nitrate  with 
vegetable  fibre  of  any  sort  involves  not  only  a  destruction  of  the  fibre,  but 
also  of  the  silver  nitrate,  so  that  the  preparation  in  a  short  time  loses  its 
desirable  qnalities."  He  advises  instead  the  use  of  asbestos  felt  which 
has  been  heated  before  the  blow-pipe  to  eliminate  all  vegetable  matter 
previous  to  saturation  with  the  solution. 

Holmes  suggests,  in  the  treatment  of  j)roximal  cavities,  that  the  walls  be 
"cut  away  to  a  V  shape,  and  with  a  piece  of  gutta-percha  softened  by 
heat,  of  the  proper  size  of  the  space,  bring  the  surface  to  come  in  contact 
with  the  diseased  part  of  the  teeth  in  contact  with  the  powdered  crystals 
of  silver  nitrate,  and  carry  it  into  place  in  the  tooth  or  teeth  prepared  for 
its  reception,  packing  it  firmly,  and  leaving  it  there  to  be  worn  away  by 
use  in  mastication.  "When  that  takes  ijlace  the  surface  of  the  teeth  will 
be  found  black  and  hard,  with  no  sensitiveness  to  the  touch  or  to  changes 
in  temperature,  and  they  will  remain  so  indefinitely.  In  case  the  child 
is  so  timid  as  to  ])revent  this  course,  dry  the  cavity,  take  out  as  much 
softened  dentin  as  the  patient  will  permit,  carry  the  crystals  on  softened 
gutta-percha  into  the  cavity,  and  i)ack  it  there,  leaving  it  until  such  time 
as  desirable  to  make  a  more  thorough  operation." 

Goddard  deprecates  the  practice  of  making  Y-shaped  separations  in 
these  cases,  and  believes  it  better  to  open  proximal  cavities  from  the 
morsal  surface,  "as  the  full  diameter  of  the  teeth  is  necessary  to  preserve 
the  fulness  of  the  arch." 

The  writer  maintains  the  same  opinion,  but  would  add  another  reason, 
— viz.,  that  the  iJ reservation,  when  j)ossible,  of  the  full  size  of  the  morsal 
surface  of  the  teeth  is  important  from  the  fact  that  if  they  are  cut  away 
the  power  of  thoroughly  grinding  the  food  is  by  that  much  curtailed,  and 
the  child  forms  the  habit  of  swallowing  its  food  before  it  is  properly 
masticated. 

EXCISION. 

In  the  operation  of  excision  the  diseased  part  is  cut  away  with  files,  or  with 
disks  revolved  by  the  dental  engine,  and  the  surface  thoroughly  polished. 
This  operation  is  only  admissible  in  the  superficial  stage  of  the  disease. 
The  advisability  of  the  operation  has  been  seriously  questioned,  however, 
by  some  of  the  best  operators  in  the  profession  ;  and  in  the  light  of  the 
recent  discoveries  made  by  "Williams  in  the  modus  operandi  of  enamel 
decay  it  would  seem  that  the  operation  can  be  of  very  little  benefit  as  a 
therapeutic  measure.  It  may  possibly  retard  the  progress  of  the  disease 
for  a  time  by  removing  the  roughened  surface  of  the  enamel,  and  thus 
making  it  a  somewhat  less  favorable  surface  for  the  attachment  of  the 
zymogenic  fungi,  but  as  a  permanent  cure  it  is  not  to  be  relied  upon, 


TREATMENT    OF    CARTES. 


173 


althoiigli  every  operator  of  experience  has,  no  doubt,  seen  cases  in  which 
the  operation  has  proved  permanently  curative. 

Many  of  the  older  operators,  fifty  years  ago,  practised  the  operation 
very  extensively,  and  they  were  often  quite  successful  in  arresting  the 
progress  of  the  disease,  but  they  did  it  at  a  great  sacrifice  of  tooth-struc- 
ture. Approximal  cavities  in  bicuspids  and  molars  were  often  treated  in 
this  way,  the  method  being  to  cut  large  Y-shaped  spaces,  the  apex  of  the 
V  at  the  cervices  of  the  teeth,  the  base  being  so  broad  that  the  surfaces 
thus  formed  would  be  kept  clean  by  the  friction  of  mastication. 

Arthur  at  a  later  period  (1871)  introduced  and  extensively  practised  a 
modified  form  of  the  operation  as  a  prophylactic  as  well  as  a  curative 
method. 

He  argued  that  the  great  majority  of  individuals  suffered  from  proxi- 
mate caries  of  their  teeth  ;  also  that  it  was  j)ossible  for  the  dentist  by  in- 
telligent observation  to  determine  in  advance  those  cases  in  which  caries 
would  occur.  Observation  had  also  taught  that  when  the  teeth  were  so 
arranged  naturally  that  they  were  well  separated  from  each  other,  im- 
munity from  caries  was  the  general  rule  ;  further,  that  the  separation  by 
filing,  practised  by  the  older  dentists,  often  arrested  the  disease  and  gave 
immunity  to  such  surfaces  from  further  destruction  ;  that  accidental  in- 
juries to  the  teeth  which  exposed  the  dentin,  when  in  locations  that  were 
kept  clean  by  the  friction  of  mastication,  and  the  practice  of  many  abo- 
riginal races  of  filing  their  teeth  for  various  purposes  without  injury 
to  the  dentin,  led  him  to  believe  that  the 
enamel  might  be  removed  without  harm  to 
the  teeth,  provided  the  surfaces  and  spaces 
thus  made  were  of  such  shape  that  they 
could  be  readily  cleansed.  The  friction  of 
mastication  and  ordinary  care  on  the  part 
of  the  patient,  he  believed,  would  be  suffi- 
cient to  prevent  the  occurrence  of  the  dis- 
ease. The  method  which  he  advised  and 
practised  was  to  separate  the  bicuspids  and 
molars  by  means  of  thin  corundum  disks  (Fig.  295),  but  as  far  as  possible 
retaining  the  natural  contour  of  the  proximate  surfaces.  The  six  anterior 
teeth  were  separated  by  the  same  means,  but  in  this  case  the  separation 
consisted  in  forming  Y-shaped  spaces  upon  the  lingual  surfaces,  the  apex 
of  the  Y  being  directed  towards  the  lip  and  the  base  towards  the  tongue. 

For  a  time  this  practice  was  followed  by  a  considerable  number  of 
practitioners,  but  it  gradually  fell  into  disrei^ute  from  the  fact  that  the 
claims  of  its  advocate  could  not  be  realized  by  those  who  adopted  it, 
except  in  a  few  isolated  cases. 


Fig.  295. 


Corundum  disks. 


CHAPTEE    XII. 

TREATMENT   OF   CARIES   (CONTINUED). 

The  separation  of  contiguous  or  adjoining  teeth,  the  proximate  sur- 
faces of  which  may  be  the  seat  of  caries,  is  an  important  and  an  essential 
procedure,  preliminary  to  the  operation  of  removing  diseased  tissue  and 
restoring  the  tooth  to  its  original  form  by  the  introduction  of  some  suit- 
able filling-material. 

The  enlarging  of  the  interproximate  space  for  a  brief  period  is  not 
only  necessary,  that  a  direct  view  of  the  cavity  may  be  obtained,  and 
facilitate  the  operation  of  cavity  i)reparation,  but  that  it  may  give  oppor- 
tunity for  restoring  the  original  contour  of  the  teeth  with  the  filling 
material,  so  that  when  they  return  to  their  normal  positions  their  relations 
to  each  other  will  be  the  same  as  before  they  were  attacked  by  the  carious 
process. 

Separation  by  filing  is  to  be  deprecated,  and  in  these  days  it  is  rarely 
practised,  as  the  restoration  of  contour  is  not  possible  by  this  method  of 
separation. 

The  resulting  consequences  from  failure  to  restore  the  normal  contour 
and  mutual  relationship  of  such  teeth,  particularly  the  bicuspids  and 
molars,  is  often  very  serious.  When  permanent  separations  are  made, 
either  by  filing  or  failure  to  restore  the  contour  so  that  the  approximal  sur- 
faces do  not  '^  knuckle  up"  to  each  other,  food  is  driven  iuto  the  inter- 
proximate space,  to  the  great  annoyance  of  the  patient  and  often  painful 
and  serious  injury  to  the  gum,  inducing  pericementitis,  recession  of  the 
gum,  and  sometimes  loss  of  the  affected  tooth. 

In  dealing  with  the  anterior  teeth  the  restoration  of  contour  is  also 
important  from  the  aesthetic  stand-point.  Teeth  which  have  been  perma- 
nently separated  by  filing  x^resent  mutilations  which  in  themselves  con- 
stitute a  deformity,  while  they  often  move  out  of  their  normal  position  by 
tilting  towards  each  other,  or  assuming  other  positions  out  of  harmony 
with  the  natural  arrangement  of  the  arch. 

The  separation  of  the  teeth  is  a  procedure  which  calls-|Mj  considerable 
care  to  avoid  injury  to  the  pericemental  membrane  a»F  gum  and  to 
render  the  process  as  nearly  painless  as  possible.  There  is  considerable 
difference  in  individuals  as  to  the  amount  of  soreness  and  pain  produced 
by  separating  the  teeth.  In  children  and  young  people  the  necessary 
space  is  gained  much  more  quickly  and  with  less  irritation  than  when  the 
alveolar  walls  have  become  firm  and  compact,  or  when  the  arch  is  full  and 
the  teeth  are  in  close  proximity.  In  the  former  the  bone  yields  readily 
and  permits  an  expansion  of  the  arch,  while  in  the  latter  the  resistance  to 
force  is  much  greater  and  the  process  of  expansion  considerably  slower. 
174 


TREATMENT    OF    CARIES.  175 

A  certain  amount  of  space  is  always  gained,  even  in  a  full  arch,  by  the 
closing  of  the  slight  spaces  which  often  exist  between  the  teeth.  It  is 
therefore  important  that  the  force  applied  and  the  materials  or  aiDpliances 
used  should  be  adapted  to  the  conditions  presented  in  each  individual 
case.  Constant  and  sustained  pressure,  if  the  force  used  is  not  too  great, 
will  separate  the  teeth  more  quickly  and  with  less  irritation  than  if  applied 
intermittingly.  With  such  precautions  as  would  be  suggested  by  good 
judgment  no  harm  can  come  from  the  process,  even  when  the  tissues  are 
irritable  or  the  structures  are  of  the  firmest  character.  There  is  no  diffi- 
culty in  obtaining  sufficient  space  for  any  operation  if  proper  care  is  ex- 
ercised and  the  force  is  steadily  and  mildly  applied. 

Methods  of  Separation. — Separations  may  be  obtained  by  the  em- 
ployment of  various  means,  the  selection  of  which  should  be  governed  by 
the  conditions  and  requirements  of  the  case  in  hand, — viz.,  the  amount  of 
space  required,  the  time  in  which  it  must  be  accomplished,  the  firmness 
and  irritability  of  the  structures,  and  the  location  of  the  teeth  to  be  sepa- 
rated. 

Two  methods  are  employed  to  gain  space  by  wedging,  one  termed 
immediate  or  direct,  the  other  gradual  or  indirect. 

Immediate  or  direct  wedging  is  most  applicable  to  the  anterior  teeth, 
where  usually  only  a  limited  amount  of  space  is  required.  Its  greatest 
advantage,  however,  lies  in  its  use  as  a  method  of  obtaining  space  for  the 
examination  of  the  proximate  surfaces,  and  to  permit  the  introduction  of 
polishing  strips,  for  the  removal  of  superficial  softening  of  the  enamel, 
stains  and  discolorations,  and  for  the  purpose  of  repolishing  fillings. 

Immediate  separation  may  be  accomplished  by  forcing  properly  shaped 
wooden  wedges  between  the  teeth,  either  by  steady  pressure  or  by  driving 
with  the  mallet.  The  wedges  should  be  made  of  hard,  close-grained  wood, 
orange- wood  being  the  best.  The  wedges  should  be  inserted  between  the 
teeth,  one  near  the  morsal  edge,  the  other  at  the  cervix,  care  being  taken 
not  to  impinge  upon  the  gum  in  such  a  manner  as  to  bruise  or  otherwise 
injure  it.  These  are  then  alternately  forced  farther  and  farther  until  the 
desired  space  is  obtained. 

The  angular  form  of  the  interproximate  space  sometimes  makes  it  im- 
possible to  use  a  wooden  wedge,  as  the  wedge  travels  towards  the  gum  as 
soon  as  force  is  applied,  instead  of  producing  lateral  pressure  upon  the 
approximal  surfaces  and  insuring  fixation  of  the  teeth. 

Mechanical  Separation. — Various  mechanical  appliances  have  been 
invented  for  the  immediate  separation  of  the  teeth.  The  best  for  separating 
the  anterior  teeth  is,  no  doubt,  the  one  invented  by  Woodward,  while 
those  best  adapted  for  gaining  space  between  the  bicuspids  and  molars  are 
the  Parr  and  the  Perry  forms  (Figs.  296^  and  297). 

Separations  made  by  the  aid  of  these  instruments  for  the  examination 
of  the  approximal  surfaces  or  to  gain  space  for  operations  are  far  less 
painful  than  those  obtained  by  driving  the  wooden  wedge.  They  are  also 
valuable  for  increasing  the  space  gained  by  other  methods,  and  for  fixing 
the  teeth  which  have  been  separated  by  the  gradual  method,  and  in  which 
there  still  remains  a  little  pericemental  irritation  and  soreness.     When 


176  OPERATIVE    DENTISTRY. 

the  patient  is  pressed  for  time  it  often  becomes  necessary  to  operate  before 
the  irritation  lias  entirely  subsided,  but  without  some  such  support  as  this 
it  would  be  impossible  to  operate,  on  account  of  the  discomfort  which 
would  be  caused  to  the  patient,  and  which  would  be  increased  at  every 
stroke  of  the  mallet. 

Mechanical  separators,  however,  have  the  disadvantage  that  they  cannot 
be  used  in  all  locations,  even  if  one  possess  a  half-dozen  or  more  different 

Fig.  296. 


Parr  separator.  Perry  separator. 

forms,  while  with  the  Perry  instrument  there  is  a  constant  tendency  for  it 
to  slip  towards  the  gums.  This  can,  nevertheless,  be  overcome  by  placing 
beneath  the  bows  small  pieces  of  gutta-percha  or  india-rubber. 

Parr's  instrument  is  more  universal,  but  it  is  decidedlj^  more  clumsy. 

Gradual  or  indirect  wedging  may  be  accomplished  by  the  introduction 
between  the  teeth  of  thin  wooden  tvedges,  which  should  be  changed  to 
thicker  ones  each  day,  depending  upon  the  swelling  of  the  fibres  under 
moisture  to  produce  the  sej)aration. 

Linen  tape,  either  waxed  or  unwaxed,  is  an  admirable  material  with 
which  to  sex)arate  the  teeth. 

Waxed  tape  will  j)ass  more  readily  between  teeth  that  stand  close 
together  than  will  the  unwaxed,  but  it  does  not  move  the  teeth  so  quickly 
as  the  unwaxed,  the  wax  preventing  the  rapid  absorption  of  moisture  and 
swelling  of  the  fibres.  It  becomes  necessary  sometimes,  however,  to  begin 
the  separation  by  the  immediate  method, — either  with  a  wedge  of  wood  or 
the  separator, — as  it  is  impossible  to  get  anything  between  the  teeth  without 
the  application  of  considerable  force.  As  soon  as  sufficient  space  is  gained, 
the  tape  may  be  inserted  and  the  separating  appliance  removed.  The  tape 
should  be  removed  each  day  and  a  thicker  one  inserted,  until  such  time 
as  the  required  space  is  obtained,  when  gutta-percha  may  be  packed  be- 
tween the  teeth  and  allowed  to  remain  until  all  soreness  has  disappeared. 
In  fact,  this  or  similar  means  of  retaining  the  teeth  in  their  separated 
position  should  always  follow  the  removal  of  the  material  used  for  gradu- 
ally separating  the  teeth,  as  it  is  always  best  to  wait  for  soreness  to  dis- 
appear before  beginning  the  operation  of  filling. 

Pledgets  of  cotton  may  also  be  used  as  a  means  of  separating  the  teeth, 
especially  in  the  posterior  teeth  when  the  cavity  has  been  broken  through 
the  morsal  surface.  The  pledgets  should  be  ]3acked  as  tightly  as  possible 
when  the  cavity  is  not  so  deep  as  to  involve  a  vital  pulp.  The  cotton  may 
then  be  saturated  with  sandarach  varnish  to  bind  the  fibres  together. 


TREATMENT    OF    CARIES.  177 

The  front  teeth  may  be  separated  with  the  same  material  by  twisting 
it  into  a  strand,  drawing  this  between  the  teeth,  and  cutting  the  ends 
short. 

The  cotton  will  act  more  rapidly,  however,  without  the  sandarach 
varnish,  as  this  retards  the  absorption  of  water,  and  consequently  the 
swelling  of  the  fibres  is  more  gradual. 

India-rubber — caoutchouc — in  strij)S  of  various  widths  is  i)erhai3S,  on  ac- 
count of  its  effectiveness,  more  frequently  used  than  any  other  means  of 
producing  gradual  separation.  When  a  strip  of  india-rubber  is  drawn 
between  two  teeth  the  middle  portion  is  pressed  to  great  thinness,  the  ends 
acting  as  two  opposing  wedges,  the  elasticity  or  resilience  of  the  material 
constantly  drawing  the  ends  or  wedges  together  until  a  space  is  obtained 
equal  to  the  thickness  of  the  strip.  Great  caution,  however,  should  be 
exercised  in  using  this  material,  as  its  power  is  very  great,  and  serious 
pericemental  inflammation  may  be  induced  by  the  use  of  strips  which  are 
too  thick. 

Separations  of  almost  any  desired  width  may  be  obtained  with  this 
material,  with  little  or  no  irritation,  if  only  the  strips  used  are  thin  enough 
and  are  changed  every  day. 

Red  base-plate  gutta-percha  has  been  recommended  by  Bonwill  as  a  de- 
sirable material  with  which  to  gradually  separate  the  teeth.  It  should  be 
packed  firmly  into  the  open  cavities  and  existing  space  between  the  teeth, 
depending  u^Don  the  force  of  mastication  to  produce  expansion  by  driving 
the  material  towards  the  gum. 

This  material  is  also  valuable  for  exposing  the  cervical  margins  of  the 
cavities  which  are  covered  by  overlapping  gum-tissue,  by  packing  it  into 
the  cavity  and  interproximate  space.  It  is  much  better  than  cotton  for 
this  purpose,  as  it  does  not  absorb  septic  material. 

EXCLUSION   OF    MOISTURE. 

The  exclusion  of  moisture  during  all  operations  upon  the  teeth  is  of  the 
greatest  importance.  The  presence  of  the  oral  secretions  is  often  a  serious 
obstacle  to  the  performance  of  many  operations,  and  when  the  flow  is  ex- 
cessive it  becomes  a  matter  of  considerable  annoyance  to  the  patient.  All 
operations  upon  the  teeth  are  more  successfully  performed  by  the  exclusion 
of  inoisture  than  when  the  mouth  is  flooded  with  its  secretions ;  but  for 
the  introduction  of  gold  as  a  filling-material,  and  in  the  treatment  of  de- 
vitalized teeth,  it  becomes  an  absolute  necessity. 

In  the  earlier  days  of  modern  dentistry  the  question  of  the  exclusion 
of  moisture  during  a  long  and  tedious  operation  with  cohesive  gold  caused 
the  dentist  many  anxious  thoughts,  and  added  not  a  little  to  the  nervous 
strain  incident  to  his  professional  life  ;  a  strain  which  the  younger  mem- 
bers of  the  profession  can  hardly  realize  or  appreciate,  since  they  are 
furnished  with  a  material — the  rubber  dam — which  removes  entirely  all 
anxiety  upon  the  part  of  the  operator  that  his  operation  may  be  com- 
pletely ruined  by  the  entrance  of  moisture  and  his  labor  come  to  naught. 

Various  methods  and  appliances  have  been  introduced  for  the  purpose 
of  securing  and  maintaining  dryness  in  the  field  of  oiDeration,  including 

12 


178  OPERATIVE    DENTISTRY. 

the  napkin,  bibulous  paper,  cotton  pads,  gauze,  saliva  ejectors,  and  tlie 
rubber  dam. 

Napkins. — The  use  of  napkins  as  a  means  of  excluding  moisture  is  the 
oldest,  and  was  for  many  years  the  only  one,  with  which  the  older  practi- 
tioners daily  fought  the  battle  of  maintaining  a  dry  field  for  their  opera- 
tions. It  is  still  a  valuable  method,  and  is  often  resorted  to  in  those  cases 
in  which  the  rubber  dam  cannot  be  employed,  as,  for  instance,  in  the  treat- 
ment of  molars  which  are  only  partially  erupted,  or  in  those  persons  to 
whom  the  dam  is  so  disagreeable  or  nauseating  that  they  will  not  permit 
its  use. 

Napkins  for  this  purpose  should  be  made  of  the  best  diaper  or  bird's- 
eye  linen  of  various  sizes,  six  inches,  nine  inches,  and  twelve  inches  square 
being  the  most  useful  sizes.  The  smallest  ones  folded  in  pads  the  full 
length  of  the  napkin  are  admirable  for  use  in  the  lower  part  of  the  mouth, 
and  are  applied  by  placing  one  end  of  it  opposite  the  incisor  teeth,  be- 
tween the  tongue  and  the  lingual  surfaces  of  the  teeth,  carrying  the 
middle  of  the  napkin  to  the  angle  of  the  jaw,  folding  it  upon  itself,  and 
laying  the  other  half  between  the  cheek  and  the  buccal  surfaces  of  the 
teeth,  and  holding  it  in  place  with  the  thumb  and  index-finger  of  the  left 
hand.     If  the  tongue  is  raised  before  the  napkin  is  applied  upon  the  lin- 

FiG.  298.  Fig.  299. 


Bicuspid  napkin  clamp.  Molar  napkin  clamp. 

gual  side  of  the  teeth,  the  tongue  will  hold  this  end  of  the  napkin  in  place, 
and  at  the  same  time  press  it  down  upon  the  orifices  of  the  sublingual 
and  submaxillary  glands.  A  better  means  of  holding  the  napkin  in  posi- 
tion is  to  apply  the  Ivory  napkin  clamp.     (See  Figs.  298  and  299). 

The  larger  napkins  are  folded  by  taking  hold  of  one  corner  with  the 
thumb  and  index-finger  of  the  left  hand  and  the  lateral  corners  rolled  or 
folded  in.  It  is  applied,  for  instance,  to  the  upper  left  side  by  passing  the 
corner  held  by  the  left  thumb  and  finger  under  the  lip  at  the  left  oral 
commissure,  holding  it  there  with  the  index-finger  of  the  left  hand,  and  with 
the  index-finger  of  the  right  hand  or  a  pair  of  dressing  forceps  carry  the 
thicker  part  of  the  napkin  backward  to  the  tuberosity  of  the  jaw ;  then 
folding  it  upon  itself,  it  is  brought  forward  along  the  lingual  surfaces  of 
the  teeth  and  maintained  in  its  position  with  the  left  index -finger.  The 
free  end  of  the  napkin  is  then  spread  out  so  as  to  cover  the  lower  lip. 
The  procedure  for  the  right  side  is  the  same,  with  the  exception  that  the 
hands  are  reversed. 

Bibulous  paper,  prepared  gauze,  and  cotton  pads  are  now  used  by  some 


TREATMENT    OF    CARTES.  179 

operators  to  the  exclusion  of  napkins.  Their  application  is  similar  to 
that  of  napkins  folded  into  pads. 

The  moisture  which  appears  around  the  necks  of  teeth,  coming  from 
the  glands  at  the  margin  of  the  gums,  is  often  quite  troublesome  when  only 
the  napkin  or  similar  means  are  used  to  exclude  the  moisture.  This  may 
be  controlled  by  packing  small  pieces  of  bibulous  paper  between  the  teeth 
at  the  cervix. 

Saliva  Ejectors. — These  instruments  are  exceedingly  useful  in  con- 
junction with  napkiuSj  bibulous  paper,  etc.,  or  with  the  rubber  dam,  for 
removing  the  secretions  that  accumulate  during  the  operation.  In  many 
operations  the  necessary  position  of  the  jaws  is  such  as  to  make  it  impos- 
sible for  the  patient  to  swallow,  hence  the  accumulation  of  saliva  is  often 
very  troublesome  to  both  the  patient  and  the  operator,  especially  so  when 
the  secretions  are  normally  excessive,  or  are  greatly  increased  by  the 
stimulation  of  operative  procedures.  These  instruments  act  upon  the 
principle  of  the  siphon,  and  are  made  for  attachment  to  the  water-supply 
and  used  in  connection  with  the  fountain  cuspidors. 

Rubber  Dam. — Barnum  conferred  a  great  boon  upon  suffering  humanity 
and  greatly  lightened  the  labors  of  the  dentist  by  his  invention  of  apply^ 
ing  sheet-rubber  or  rubber  dam  as  a  means  of  excluding  moisture  from 
the  field  of  dental  operations,  thus  making  it  possible  to  save  many  teeth 
which  before  were  condemned  to  the  forceps.  It  has  universal  applica- 
tion in  all  parts  of  the  mouth  wherever  a  tooth  or  root  has  sufficiently 
emerged  from  the  gum  for  the  dam  to  be  passed  over  it. 

It  is  of  greatest  value,  however,  in  the  preparation  and  filling  of 
proximal  cavities  where  the  disease  has  extended  beneath  the  gum,  and 
in  which  the  exclusion  of  the  secretions  and  of  blood  is  a  difficult  matter 
with  any  other  means  at  our  command.  For  the  exclusion  of  moisture 
and  septic  secretions,  and  the  protection  of  the  soft  tissues  from  medica- 
ments in  the  treatment  of  devitalized  teeth,  alveolar  abscesses,  etc.,  it  is 
indispensable. 

Rubber  dam  is  made  in  three  thicknesses,  known  as  thin,  medium,  and 
thick,  and  usually  sold  in  strips  varying  in  width  from  five  to  seven  inches. 
The  preference  for  general  use  lies  with  the  medium  thickness,  although 
it  is  well  to  have  all  three  thicknesses  on  hand.  The  quality  of  the  rub- 
ber is  a  matter  of  first  importance  ;  it  should  be  strong,  elastic,  extensible, 
and  free  from  odor.  Exposure  to  the  atmosphere  and  the  high  tempera- 
tures of  summer  weather  cause  deterioration  in  these  qualities  and  soon 
render  it  worthless.  To  protect  it  as  much  as  possible  from  these  deterio- 
rating influences  it  is  usually  sealed  in  tin  cans  or  boxed.  It  should  be 
cut  for  use  into  squares  and  triangular  i)ieces,  the  squares  from  five  to  seven 
inches,  the  triangular  pieces  being  made  by  folding  the  squares  corner- wise 
and  dividing  them.  A  form  of  rubber  dam  has  lately  been  introduced 
which  is  coated  with  a  metallic  aluminum  powder,  which  gives  it  a  very 
light  appearance  and  adds  greatly  to  its  usefulness  by  making  it  luminous. 
The  aj)plication  of  the  rubber  dam  is  to  the  student  in  his  first  attempt  to 
adjust  it  a  somewhat  difficult  procedure  ;  to  the  older  practitioner  who  has 
become  expert  by  long  practice  it  is  usually  a  simple  matter,  requiring 


180 


OPERATIVE    DENTISTRY. 


but  a  moment  of  time  ;  and  yet  occasionally  a  case  will  present  in  which 
its  application  will  require  all  his  ingenuity  and  patience. 

In  adjusting  the  dam  to  a  tooth  with  a  simple  cavity  upon  the  morsal 
surface,  a  hole  should  be  pinched  or  cut  at  such  a  location  as  will  permit 
the  dam  to  lie  smoothly  over  the  mouth  after  its  adjustment  to  its  position. 
The  dam  may  be  adjusted  by  grasping  the  two  upper  corners  with  the 
thumb  and  index-finger  of  both  hands,  and  with  the  middle  finger  of 
each  hand  placed  on  opposite  sides  of  the  hole  through  which  the  tooth  is 
to  pass,  the  rubber  is  put  on  the  stretch.  This  enlarges  the  hole  in  the 
rubber,  and  it  is  forced  over  the  tooth  by  passing  first  one  edge  and  then 
the  other  of  the  opening  between  the  mesial  and  distal  proximal  spaces, 
and  carrying  it  well  up  to  the  cervix.  Fig.  300  shows  the  rubber  dam  in 
position  upon  the  upper  incisor  teeth,  the  upper  corners  of  the  dam  being 


Fig.  300. 


Fig.  301. 


Rubber  dam  applied. 


Rubber-dam  holder. 


secured  with  a  rubber-dam  holder  (Fig.  301)  Various  other  forms  of 
holders  are  also  for  sale  by  the  dealers,  and  the  operator  may  suit  himself 
with  almost  any  desired  form.  The  rubber  dam  may  be  held  smooth  by 
attaching  weights  to  the  lower  corners. 

If  two  or  more  teeth  are  to  be  isolated,  it  then  becomes  necessary  to 
punch  the  same  number  of  holes  in  the  dam,  so  locating  them  that  when 
the  dam  is  placed  in  position  the  straits  between  the  holes  will  be  just  a 
trifle  wider  than  the  spaces  between  the  teeth ;  the  edges  of  the  dam 
around  the  cervices  of  the  teeth  should  then  be  turned  under,  using  the 
point  of  any  straight-pointed  instrument  of  suitable  size.  The  dam  thus 
grasping  the  cervix  of  the  tooth  acts  as  a  valve,  and  effectually  excludes 
all  moisture  from  the  teeth  so  enclosed.  To  secure  the  dam  in  position,  a 
ligature  may  be  passed  around  each  tooth  and  tied  with  the  surgeon's  knot, 
or  clamps  of  various  forms  (Fig.  302)  are  used  alone  for  the  same  purpose, 


TREATMENT   OF    CARIES. 


181 


or  in  conjunction  with  the  ligatures.  Properly  constructed  clamps  are 
so  shaped  that  they  materially  assist  in  holding  the  dam  away  from  the 
crown  of  the  tooth,  thus  causing  less  obstruction  to  the  entrance  of  light 


Fig.  302. 


Ivory's  claraps. 

and  giving  a  better  view  of  the  field  of  operation.  The  Ivory  clamps 
possess  these  very  desirable  features  to  a  greater  extent  than  any  others  at 
present  known  to  the  writer. 

Fig.  303. 


The  Ottolengui  clamp  applied. 

The  Ottolengui  clamp  (Fig.  303)  also  possesses  many  of  the  desirable 

features. 

Fig.  304. 


Dr.  How's  cervix  screw  clamp. 


The  How  cervix  screw  clamp  (Fig.  304)  is  an  admirable  instrument  for 
securing  the  dam  and  exposing  the  cervical  margin  in  cervical  cavities. 
Its  application  is  shown  in  the  illustration. 


182 


OPERATIVE    DENTISTRY. 


Specially  constriictecl  forceps  are  necessary  in  the  adj  ustment  of  all 
forms  of  spring  clamps  like  those  shown  in  the  preceding  illustrations. 

Fig.  305  shows  a  method  of  adjusting  the  clamp  and  the  rubber  dam  at 
the  same  time.  The  clamp  in  the  illustration  is  known  as  the  Elliot  molar 
clamp,  and  is  a  favorite  appliance  with  many  operators. 

Fig.  305. 


Elliot's  clamp  and  forceps. 


When  the  teeth  are  very  close  together  and  the  alveolar  walls  are  very 
firm,  it  is  sometimes  a  difficult  matter  to  pass  the  dam  between  the  teeth 
without  some  special  preparation  of  the  contiguous  surfaces.  The  rubber- 
dam  applier,  shown   in  Fig.  306,   duplicates  the  fingers  and  materially 


Fig.  306. 


Rubber-dam  applier 


assists  in  forcing  the  dam  between  the  teeth.  In  all  such  cases  the  passage 
of  the  dam  may  be  facilitated  by  first  lubricating  the  surfaces  by  passing 
floss-silk  between  them  which  has  been  charged  with  vaseline,  cosmoline,  or 
toilet  soap. 

The  holes  in  the  dam  may  be  made  either  with  the  punch  (Fig.  307), 
the  scissors,  or  by  stretching  the  dam  over  .the  end  of  a  small,  round. 

Fig.  307. 


Ainsworth's  rubber-dam  punch. 

tapering  instrument, — the  reverse  end  of  a  mallet-plugger  will  answer  the 
purpose, — and  nicking  the  rubber  near  the  point  with  a  sharp  knife  ;  the 
result  is  a  perfectly  round  hole.     Any  desired  size  may  thus  be  obtained ; 


TREATMENT    OF    CARIES. 


183 


the  lower  down  upon  the  instrument  the  nick  is  made  the  larger  the  hole  ; 
the  tighter  the  dam  is  drawn  the  smaller  the  hole  will  be. 

The  writer  has  used  this  method  many  years,  to  the  exclusion  of  all 
others,  and  with  perfect  satisfaction. 

Fig.  308  shows  the  relative  size  of  holes  adaj^ted  to  (1)  incisors  and 
cuspids,  (2)  bicuspids,  (3)  molars.     The  depressed  rubber  dam  (Fig.  309) 


Fig.  SOS. 


Fig.  309. 


Depressed  nibber  dam. 

and  the  Denham  coffer-dam  shield  (Fig.  310)  are  often  found  useful  in 
operations  for  children  and  in  preliminary  treatments,  or  when  remedies 
are  to  be  used  which  it  is  desirable  should  not  come  in  contact  with  the 
surrounding  tissues  of  the  mouth.  Fig.  311  shows  the  Denham  coffer-dam 
shield  adjusted  and  secured  with  a  clamp.  A  small  mirror  (Fig.  312) 
may  be  inserted  in  the  depressed  rubber  dam  for  the  purpose  of  greater 
illumination. 

Fig.  310.  Fig.  311. 


'i  ^  s\ 


Denham  coffer-dam  shield. 
Fig. -312. 


Mirror. 


Denham  coffer-dam  shield  adjusted. 


Nausea  and  other  unpleasant  symptoms  are  often  occasioned  by  the 
contact  of  the  rubber  dam  with  the  tongue  and  palate,  and  from  the  un- 
pleasant odor.  The  nausea  may  be  relieved  by  spraying  the  mouth  and 
throat  with  a  two  per  cent,  solution  of  cocaine  in  water,  while  the  un- 
pleasant odor  may  be  overcome  by  dipping  the  dam  in  rose-water  or  other 
toilet- water.  Jack  recommends  painting  the  parts  with  tincture  of  cam- 
phor, while  the  nervous  conditions  which  sometimes  appear  on  adjusting 
the  dam  and  covering  the  mouth  may  be  overcome  by  requesting  "the 
patient  to  breathe  freely  through  the  nose. 


CHAPTEE    XII I. 

HYPERSENSITIVE   DENTIN. 

Dentin  is  a  fibro-calcareous  structure,  tubular  in  character,  the  tubuli 
passing  from  the  i)ulp-chamber  to  the  periphery  of  the  dentin,  branching 
in  their  course,  and  terminating  in  minute  tubules,  which  unite  to  form  an 
intricate  plexus.  These  tubuli  are  each  of  them  traversed  by  a  minute 
fibril  or  filament,  which  is  generally  thought  to  be  a  prolongation  of  an 
odontoblastic  cell,  and  that  through  these  fibrils  sensation  is  conveyed  to 
the  dental  xDulp.  There  is  some  evidence,  however,  as  already  pointed 
out  in  Chapter  III.,  that  a  portion  of  the  tubuli  are  occupied  by  certain 
fibres,  which  appear  to  be  prolongations  of  the  nerve-filaments  of  the  pulp, 
or  that  the  nerve- filaments  of  the  pulp  enter  the  odontoblasts,  and  thus 
furnish  the  necessary  elements  which  fit  the  fibrillse  to  carry  sensation. 

It  has  never  been  demonstrated,  however,  that  the  fibrillte  of  the  dentin 
were  composed  of  nerve-tissue,  and  yet  there  can  hardly  be  a  doubt  that 
such  is  their  composition,  for  they  perform  the  functions  and  x^resent  all 
the  phenomena  of  nerve-tissue  under  stimulation  and  under  irritation. 

Dentin  in  its  normal  state  is  only  slightly  sensitive,  but  when  subjected 
to  irritation  from  external  agencies  it  may  become  most  excruciatingly 
%j9ersensitive.  The  degree  of  hypersensitiveness  will  dei^end  upon  the 
character  of  the  irritant,  the  point  of  attack,  its  duration,  the  condition 
of  the  oral  secretions,  the  character  of  the  structural  development  of  the 
teeth,  the  age,  and  the  physical  condition  of  the  patient. 

Irritation  from  caries  is  the  most  common  cause  of  hypersensitive  dentin, 
the  degree  of  abnormal  sensitiveness  dex^ending  largely  ux)on  the  char- 
acter of  the  carious  x^rocess.  In  the  white  or  rapid  form  of  caries  the 
hypersensitive  condition  is  usually  the  most  exalted.  In  the  brown  or  less 
rapid  form  the  sensitiveness  is  much  less,  while  in  the  NacJc  or  slow  form 
it  is  but  little  above  that  of  normal  dentin. 

The  most  sensitive  part  of  a  carious  tooth  is  just  beneath  the  protecting 
enamel  or  cementum,  on  the  periphery  of  the  dentin  at  the  terminal  ends 
of  the  fibrillse,  just  as  the  most  sensitive  part  of  the  external  surface  of  the 
body  lies  immediately  beneath  the  horny  layer  of  the  cutis  at  the  termina- 
tions or  end  organs  of  the  nerves.  It  therefore  becomes  evident  that  caries 
in  the  superficial  stage  will  x^resent  the  highest  degree  of  hyxDersensitive- 
uess  to  be  found  in  each  of  the  three  forms  of  caries.  In  other  resx^ects 
the  zone  of  greatest  sensitiveness  is  directly  beneath  the  softened  portion 
of  dentin,  the  sensitiveness  becoming  less  and  less  as  the  sound  tissue  is 
apx)roached. 

Another  cause  of  hyx^ersensitive  dentin  is  irritation  from  attrition  or 
mechanical  abrasion.  This  cause,  however,  ox^erates  so  slowly  that  certain 
184 


HYPERSENSITIVE    DENTIN.  185 

changes  may  take  place  in  the  dentin  within  the  tubuli  by  the  deposition 
of  calcific  deposits^ — ehurnation, — which  after  a  time  diminishes  or  entirely 
destroys  their  capacity  to  convey  sensation.  The  same  process  of  eburna- 
tion  sometimes  takes  place  in  chemical  abrasion  and  denudation,  thereby 
lessening  and  sometimes  entirely  obliterating  sensation. 

Exposure  of  the  cementum  from  recession  of  the  gums  is  another  very 
common  cause  of  hypersensitive  dentin,  but  here  again  nature  is  prone  to 
mitigate  the  conditions  by  the  same  calcific  changes  in  the  dentinal  tubuli. 
But  caries  often  supervenes  in  these  cases  from  lack  of  attention  upon  the 
part  of  the  patient,  who,  because  of  the  pain  induced  by  the  use  of  the 
brush,  fails  to  keep  these  surfaces  properly  clean.  There  is  also  very 
often  the  added  influence  of  acid  mucous  or  salivary  secretions,  which  by 
their  irritating  effect  tend  to  augment  the  hypersensitive  condition,  while 
the  reverse  is  true  when  the  oral  secretions  are  alkaline  or  neutral. 

Excessive  sensibility  of  the  teeth  is  often  an  accomj)animent  of  the 
catamenia,  of  dyspepsia,  neuralgia,  pregnancy,  pulmonary  tuberculosis, 
especially  in  its  later  stages,  typhoid  fever,  acute  rheumatism,  and  the 
convalescent  stage  of  fevers  in  general.  The  condition  under  these  circum- 
stances is  due  to  the  changed  or  vitiated  character  of  the  oral  secretions, 
which  have  almost  invariably  a  strongly  acid  reaction. 

Imperfect  calcification  of  the  teeth  is  another  factor  in  the  etiology  of 
hypersensitive  dentin.  The  teeth  of  children  and  of  rapidly  growing 
young  people  are,  as  a  rule,  much  more  sensitive  than  those  of  adults. 
This  is  thought  to  be  due  to  the  fact  that  the  teeth  during  childhood  and 
youth  are  still  undergoing  changes  of  development,  and  that  they  are  not 
all  fully  formed,  in  the  sense  of  being  perfectly  calcified,  until  adult  age  ; 
but  that  as  each  group  of  teeth  are  perfected  they  become  less  susceptible 
to  external  irritants,  and  consequently  less  sensitive.  Females,  however, 
as  a  general  rule,  are  more  often  sufferers  from  hypersensitive  dentin  thp^n 
are  males. 

Nervous  irritahility  is  greater  in  some  persons  than  in  others,  females 
usually  possessing  a  larger  share  than  males,  and  this  in  a  measure  accounts 
for  the  intense  suffering  which  some  of  these  individuals  endure  from 
hypersensitive  dentin.  This  exalted  irritability  of  the  nervous  system  in 
some  instances  is  only  a  passing  condition  which  has  developed  as  the 
result  of  illness,  mental  or  physical  shock,  overwork  of  mind  or  body, 
over-indulgence  in  social  pleasures,  or  of  debaucherj^ ;  while  in  other  in- 
stances it  is  an  established  condition  or  dyscrasia  peculiar  to  the  indi- 
vidual ;  or  it  may  be  a  family  peculiarity  which  has  been  transmitted  as 
an  inheritance.  In  any  event  the  suffering  is  so  great  in  some  of  these  cases 
of  hypersensitive  dentin  as  to  call  for  the  greatest  sympathy,  considera- 
tion, and  forbearance  upon  the  part  of  the  operator  during  the  preparation 
of  the  cavity.  The  dentist  who  cannot  rise  to  such  an  occasion,  and  by 
tenderness  and  sympathy  endeavor  to  carry  the  patient  through  the  trying 
moments  of  the  ordeal  without  losing  his  patience,  should  change  his 
occupation,  as  he  lacks  or  has  lost  the  most  important  qualification  for  a 
successful  dental  practitioner. 


186  OPERATIVE    DENTISTRY. 


TREATMENT   OF   HYPERSENSITIVE   DENTIN. 

The  treatment  of  hypersensitive  dentin  is  one  of  the  most  perj)lexing 
problems  with  which  the  dentist  has  to  deal,  and  consequently  the  reme- 
dies which  have  been  suggested  and  introduced  from  time  to  time  for  ob- 
tunding  the  sensation  of  dentin  have  been  legion.  Each  new  remedy  has 
generally  been  extolled  as  a  specific  ;  but  each  of  them,  after  a  few  trials, 
has  been  laid  aside,  with  the  hopes  that  were  from  the  beginning  doomed 
to  disappointment.  Specific  medication  succeeds  no  better  in  the  treat- 
ment of  dental  diseases  than  it  does  in  general  medicine.  Certain  remedies 
which  may  cure  in  one  case  often  prove  only  an  aggravation  in  another, 
and  remedy  after  remedy  may  be  tried  with  no  appreciable  beneficial 
effect ;  while,  upon  the  other  hand,  certain  drugs  have  been  found  which 
will  upon  their  application  to  the  dentin  positively  destroy  its  sensation, 
but  will  also  destroy  or  jeoj)ardize  the  vitality  of  the  pulp. 

The  treatment  of  hypersensitive  dentin  is  therefore  limited  to  those 
remedies  and  procedures  which  will  temporarily  relieve  or  mitigate  the 
suffering  incident  to  the  preparation  of  cavities,  or  to  give  permanent 
relief  in  the  various  other  forms  of  irritation  to  which  the  vital  dental 
tissues  are  subjected. 

Treatment  of  Moderate  Hypersensitiveness. — In  the  treatment 
of  moderate  hypersensitiveness  due  to  caries  the  excavation  of  the  cavity 
should  be  approached  in  a  manner  to  engender  confidence  upon  the  part 
of  the  patient  that  the  operator  will  endeavor  to  perform  his  task  with  the 
least  possible  pain  and  in  the  most  expeditious  manner  that  the  nature  of 
the  case  will  permit,  assuring  the  patient  that,  if  the  pain  is  unbearable, 
palliative  means  shall  be  employed  for  its  relief.  With  such  assurances, 
accompanied  with  a  calm,  cheerful,  and  sympathetic  manner  upon  the  part 
of  the  operator,  the  courage  of  the  patient  can  usually  be  stimulated  to  such 
a  degree  that  the  operation  may  be  completed  without  resort  to  obtunding 
agents. 

By  a  display  of  harshness  in  the  methods  of  operation,  or  an  exhibition 
of  irritability  of  temper,  or  an  unsympathetic  mood  upon  the  part  of  the 
operator,  apprehension,  dread,  and  nervous  excitement  are  increased,  and 
the  difficulties  of  controlling  the  patient  by  just  that  much  augmented. 

It  is  often  advisable  in  dealing  with  nervous  individuals,  either  adults 
or  children,  to  select  for  the  first  operation  something  that  will  cause  little 
or  no  pain,  that  they  may  become  acquainted  with  the  various  surround- 
ings and  procedures  incident  to  dental  operations.  This  will  relieve  their 
dread  and  apprehension  for  the  time,  and  thus  make  it  possible  to  advance 
by  degrees  from  the  simpler  and  comparatively  i)ainless  operations  to  the 
more  complicated  and  severer  ones. 

In  excavating  the  simpler  cases  of  moderately  hypersensitive  dentin, 
SHARP  instruments  only  should  be  used,  but  these  should  never  be  sharp- 
ened in  the  presence  of  the  patient,  for  reasons  which  are  obvious.  The 
cutting  should  be  done  by  quick,  light,  and  sure  movements,  as  such  cut- 
ting is  decidedly  less  painful  than  slow,  heavy,  scraping  movements  of  the 
instrument.     The  direction  of  the  cutting  should,   for  the  same  reason, 


HYPERSENSITIVE    DENTIN.  187 

always  be  from  the  centre  of  the  cavity  towards  the  periphery,  and  never 
towards  the  pulp.  If  burs  driven  by  the  dental  engine  are  used,  these 
should  be  sharp  and  clean -cutting,  as  dull  burs,  or  those  which  clog  and 
do  not  cut  freely,  engender  heat  by  friction,  and  thus  increase  the  pain 
incident  to  the  operation. 

If  the  bur  be  revolved  at  a  high  rate  of  speed,  and  the  contact  with  the 
sensitive  dentin  made  by  light,  quick  touches,  this  tissue  may  be  removed 
with  so  little  pain  as  to  be  quite  tolerable.  The  dread,  however,  of  the 
dental  engine  has  been  induced  by  the  reverse  of  this  method  of  operating. 

If  the  operator  prefers  to  prepare  the  cavity  in  the  moist  state,  it  will 
be  found  that  if  a  continuous  stream  of  warm  water  be  thrown  into  the 
cavity  while  excavating  with  the  bur,  the  pain  will  be  greatly  mitigated. 
On  the  other  hand,  if  the  dry  method  be  adopted,  it  will  be  found  that 
the  more  nearly  complete  desiccation  is  obtained  the  less  will  be  the  pain 
experienced. 

In  those  cases  in  which  the  hypersensitive  condition  is  so  great  as  to 
render  the  operation  of  cavity  preparation  by  the  foregoing  methods  in- 
tolerable, treatment,  either  local  or  constitutional,  must  be  instituted  to 
temporarily  mitigate  or  palliate  the  suffering.  This  treatment  may  con- 
sist of  the  exhibition  of  certain  therapeutic  remedies,  chemical  agents,  or 
anaesthetics,  either  local  or  general. 

PALLIATIVE   TREATMENT. 

The  treatment  of  the  hypersensitive  dentin  by  palliating  remedies 
applied  locally  is  sometimes  beneficial  in  i^elieving  the  pain  of  excava- 
tion. The  available  drugs  for  this  purpose  are  morphia,  veratria,  atropia, 
cocaine,  cannabis  indica,  and  chloretone.  As  neither  of  these  remedies 
produces  any  immediate  effect,  it  is  customary  to  seal  them  in  the  cavity 
— after  the  thin  enamel  edges  have  been  removed  and  the  softest  portions 
of  the  decayed  dentin  have  been  lifted  out — with  gutta-percha  or  zinc 
oxyj)hosphate  for  two  or  three  days  or  longer,  when  on  removing  the 
temporary  filling  it  will  be  found  that  the  hypersensitive  condition  has 
been  materially  lessened. 

Morphia  sulphas  and  mofphia  acetas  are  both  used  for  this  purpose,  but 
the  writer  prefers  the  acetas,  as  it  seems  to  give  the  best  results. 

To  prepare  the  morphia  for  this  purpose  it  should  be  rubbed  up  in 
glycerol,  an  eighth  of  a  grain  of  morphia  to  a  drop  of  glycerol.  The 
cavity  should  first  be  neutralized  by  irrigating  it  with  an  alkaline  solution, 
preferably  sodium  bicarbonate.  The  rubber  dam  should  then  be  adjusted, 
the  cavity  dried,  and  the  morphia  paste  carried  into  the  cavity  and  spread 
over  its  walls,  after  which  the  temporary  filling  should  be  introduced. 
The  writer  prefers  the  zinc  oxyphosphate,  for  tlie  reason  that  by  mixing  it 
soft  it  can  be  introduced  without  i)ressure,  and  this  is  an  important  advan- 
tage in  those  cases  in  which  the  dentin  is  exceedingly  sensitive. 

Veratria  is  prepared  in  the  same  manner, — one-twentieth  of  a  grain  in 
sufficient  glycerol  to  make  a  thin  paste, — spread  .over  the  surface  of  the 
cavity,  and  sealed  in  with  cement  The  veratria  acts  by  producing  paraly- 
sis of  sensation  in  the  dentinal  fibril! ee. 


188  OPERATIVE    DENTISTRY. 

Atropki  sulphas,  one-sixteenth  of  a  grain,  may  be  prepared  and  intro- 
duced in  the  same  manner  and  often  with  good  results.  Atropia  applied 
locally  relieves  x>ain  and  sensitiveness  by  its  paralyzing  effect  upon  the 
peripheral  nerves,  and  doubtless  acts  in  the  same  manner  upon  the  denti- 
nal fibrillse. 

Cocaine  citras  and  hydrochloras,  one- eighth  of  a  grain  in  glycerol,  ap- 
plied as  above,  sometimes  i:)rove  efficacious  in  overcoming  the  sensitiveness 
producing  local  anaesthesia  of  the  dentin. 

Cannabis  Indica — fluid  extracts — applied  upon  cotton  and  sealed  into 
the  cavity  will  also  sometimes  give  relief. 

Chloretone  is  perhai3S  the  most  efficient  remedy  for  this  purpose  that  has 
as  yet  been  introduced  to  the  profession.  It  is  employed  in  solution  as  a 
local  application  to  hypersensitive  dentin.  The  solution  is  made  by  mix- 
ing equal  parts  by  weight  of  sulphuric  ether  and  the  crystals  of  chloretone. 

The  chief  objection  to  the  use  of  these  remedies  is  the  great  length  of 
time  which  is  required  for  them  to  act.  This  is  explained  by  the  exceed- 
ingly small  amount  of  organic  material  in  the  dentin  and  the  low  absorp- 
tive powers  possessed  by  this  tissue. 

Constitutional  palliative  treatment  consists  in  the  exhibition  of  such 
drugs  as,  by  their  sedative  and  analgesic  action,  will  measurably  obtund 
general  sensation  for  a  short  period  of  time.  These  are  morphia,  chloral 
hydrate,  potassium  bromide,  and  whiskey  combined  with  some  of  them 
for  its  stimulating  effect. 

The  following  formulae  have  been  found  by  the  writer  to  be  very  useful 

for  this  purpose  : 

li     Morphia  sulph. ,  gr.  \  ; 
Bourbon  whiske)^  f  ^i. 
Sig. — Twenty  minutes  before  operation. 
For  an  adult. 

R     Croton  chloral  hydrate,  gr.  x  ; 
Bourbon  whiskej'',  f  ^i. 
Sig. — Thirty  minutes  before  operation. 
For  an  adult. 

R     Potassium  bromide,  gr.  xx  to  xxx  ; 
Cinnamon-water,  f  ^i. 
Sig. — Thirty  minutes  before  operation. 
For  an  adult. 

R     Potassium  bromide,  gr.  xv  to  xx  ; 
Croton  chloral  hydrate,  gr.  x  ; 
Cinnamon-water,  f  §i. 
Sig. — Thirty  minutes  before  operation. 
For  an  adult. 

CHEMICAL   TREATMENT. 

The  treatment  of  hypersensitive  dentin  by  chemical  agents  includes 
the  application  of  caloric  by  means  of  heated  air  and  such  coagulants  as 
carbolic  acid,  zinc  chloride,  caustic  potassa,  chromic  acid,  nitric  acid,  and 
silver  nitrate.  Arsenic  and  cobalt  have  also  been  recommended  for  the 
purpose  of  obtunding  hypersensitive  dentin,  but  the  dangers  which  are 


HYPERSENSITIVE   DENTIN.  189 

likely  to  follow  their  use— viz.,  of  destroying  the  vitality  of  the  pulp  aud 
ultimately  producing  discoloration  of  the  tooth — should  render  the  exhibi- 
tion of  these  drugs  for  such  a  purpose  entirely  inadmissible. 

Heated  Air. — This  means  of  obtunding  hypersensitiveness  of  the  den- 
tin was  first  suggested  by  Brockway  "^  (1872).  It  is  perhaps  the  most  gener- 
ally efficient  and  safest  means  by  which  the  dentin  may  be  temporarily 
deprived  of  its  sensation..  The  therapeutic  effect  is  produced  by  the 
abstraction  of  a  portion  of  the  water  contained  in  the  dentinal  tubuli,  or, 
in  other  words,  by  a  partial  dehydration,  which  renders  the  dentinal 
fibrillse  less  caj)able  of  transmitting  sensation.  Were  it  possible  to  com- 
pletely dehydrate  the  dentin,  complete  suspension  of  sensation  would  be 
the  result.  More  or  less  complete  dehydration  of  the  exi)osed  surface  of 
the  dentin  can  be  accomplished,  but  this  process  cannot  be  carried  to  any 
considerable  depth,  neither  is  it  necessary,  for  usually  the  hypersensitive- 
ness is  markedly  relieved  under  a  partial  dehydration  of  the  exposed 
surface. 

In  using  this  means  of  obtunding  hypersensitive  dentin  the  rubber 
dam  should  always  be  used,  first,  to  exclude  the  outside  moisture,  and 
secondly,  to  protect  the  soft  tissues  from  the  heated  air. 

Fig.  313. 


Hot-air  sj^riuge. 

The  cavity  is  then  dried  with  bibulous  paper  and  pellets  of  amadou, 
after  which  the  heated  air  may  be  thrown  into  the  cavity  from  one  of  the 
variously  formed  air  syringes.  Fig.  313  represents  the  ordinary  form  of 
warm-air  syringe,  the  cylinder  of  which  is  heated  over  an  alcohol  flame 
or  a  Bunsen  burner.  This  cylinder  contains  a  carbon  core  which  greatly 
increases  its  heating  power,  and  thus  by  means  of  the  rubber  bulb  a  con- 
tinuous stream  of  heated  air  can  be 

carried  through  the  nozzle   into  the  Fig.  314. 

cavity.  Another  form  of  syringe,  in- 
vented by  Dr.  S.  G.  Perry,  is  shown 
in  Fig.  314.  Care  is  necessary  in  the 
use  of  this  instrument  not  to  cause 
pain  by  overheating  the  surface  of  the  Perry  hot-air  syringe. 

dentin.     The  blast  of  air  first  thrown 

into  the  cavity  should  not  be  above  a  degree  of  heat  that  would  be  toler- 
ated by  the  unprotected  skin  upon  the  back  of  the  hand.  In  fact,  the 
writer  always  tests  the  degree  of  heat  to  be  first  applied  in  this  manner. 
As  the  process  of  dehydration  goes  on,  the  heat  may  be  gradually  increased 
until  a  degree  can  be  painlessly  used  that  could  not  be  tolerated  by  the 

*  Dental  Cosmos,  vol.  xiv.  p.  19. 


190  OPERATIVE    DENTISTRY, 

skin.  A  certain  anionnt  of  skill  lias  to  be  obtained  in  order  to  direct  the 
blast  of  heated  air  in  such  a  manner  as  to  cause  the  least  pain  when  it  comes 
in  contact  with  the  hypersensitive  dentin.  If  the  nozzle  of  the  syringe 
is  held  too  far  away  from  the  cavity,  the  heated  air  in  passing  through  the 
surrounding  atmosphere  becomes  cooled  and  thus  causes  pain  ;  while,  upon 
the  other  hand,  if  it  is  held  too  near,  the  blast  is  liable,  by  its  high  degree 
of  heat,  to  cause  equally  severe  pain.  In  applying  heated  air  it  is  best  to 
begin  gently  with  a  single  short  blast,  repeated  at  intervals  of  a  few  sec- 
onds, but  as  dehydration  progresses  the  length  and  force  of  the  blast  may 
be  increased  and  at  shorter  intervals  until  the  pain  ceases. 

Fig.  315. 


Improved  electric  hot-air  syringe. 

Another  instrument  for  this  purpose  is  shown  in  Fig.  315.  This 
syringe  has  a  glass  nozzle  in  which  is  a  spiral  loop  or  platinum  wire,  con- 
nected by  flexible  copper  cords  to  a  low  voltage  electric  current.  The 
platinum  loop  can  be  heated  to  any  degree  desired,  and  by  pressure  upon 
the  rubber  bulb  attached  to  the  opposite  end  of  the  instrument  a  con- 
tinuous stream  of  air  is  made  to  pass  over  the  heated  loop  and  through 
the  nozzle.  To  protect  the  lips  from  being  burned  with  the  hot  nozzle 
it  is  covered  with  a  perforated  metal  shield.  With  this  instrument  it  is 
possible  to  maintain  an  even  degree  of  heat  for  any  length  of  time,  and 
this  is  a  very  great  advantage. 

Some  operators  prepare  the  cavity  for  dehydration  with  heated  air  by 
first  wiping  it  out  with  absolute  alcohol,  as  this  has  a  strong  affinity  for  water. 

In  severe  cases  of  hypersensitiveness  which  the  employment  of  heated 
air  does  not  relieve,  and  such  cases  are  not  infrequently  met  with,  the 
crystals  of  carbolic  acid  may  be  applied  to  the  cavity  and  followed  by  the 
heated  air  blast,  at  short  intervals,  for  two  or  three  minutes.  This  treat- 
ment will,  in  many  cases,  give  complete  relief,  and  yet  it  cannot  always 
be  relied  upon  to  do  this. 

Carbolic  Acid. — This  remedy  when  used  alone  has  but  very  little  im- 
mediate effect  in  obtunding  hypersensitive  dentin,  but  when  used  as  above 
suggested,  or  when  combined  with  oil  of  cloves  in  the  proportion  of  two 
parts  of  carbolic  acid  to  one  of  oil  of  cloves,  its  efficiency  is  increased. 
Both  carbolic  acid  and  oil  of  cloves  have  slightly  local  anaesthetic  proper- 
ties, but  when  combined,  this  property  seems  to  be  greatly  increased. 
Carbolic  acid  also  coagulates  albumin,  and  this  property  may  effect  the 
conducting  power  of  the  fibrils  with  which  it  comes  in  contact. 

The  best  results,  however,  are  obtained  with  this  combination  by  seal 


HYPERSEIsSITIVE    DENTIX.  191 

ing  it  into  the  cavity  with  zinc  oxyphosphate  cement  for  three  or  four 
days. 

Carbolic  acid  combined  with  tannic  acid  to  form  a  thin  j^aste  is  many 
times  of  service  in  treating  these  cases,  if  allowed  to  remain  in  the  cavity 
for  a  few  days.  In  apj)lying  this  combination  the  cavity  should  be  lined 
with  the  paste  and  sealed  in  with  zinc  oxyphosphate  cement. 

Zinc  Chloride. — This  is  one  of  the  oldest  and  possibly  the  most  effi- 
cient local  remedy  for  obtunding  hypersensitive  dentin  in  the  whole  arma- 
mentarium of  the  dentist.  It  must,  however,  be  used  with  the  greatest 
caution  and  good  judgment,  on  account  of  its  escharotic  action  and  its 
irritating  effect  u]3on  the  dental  pulp.  It  should,  therefore,  be  interdicted 
in  all  deep  cavities,  and  under  no  circumstances  placed  in  close  proximity 
to  a  living  pulp,  if  it  is  desirable  to  conserve  its  vitality. 

The  therapeutic  action  of  zinc  chloride  is  due  to  its  affinity  for  water 
and  its  coagulating  properties  upon  albumin,  both  of  which  have  an  ob- 
tunding effect  upon  the  dentinal  fibrillie. 

When  using  zinc  chloride  the  rubber  dam  is  indispensable,  and  it 
should  be  so  adjusted  that  there  will  be  no  possibility  of  leakage  of  fluids 
from  the  mouth  into  the  cavity,  or  of  the  zinc  chloride  coming  in  contact 
with  the  soft  tissues  of  the  mouth.  After  drying  tlie  cavity  in  the  ordi- 
nary manner,  the  zinc  chloride  is  applied  upon  a  pledget  of  cotton  to  the 
walls  of  the  cavity,  and  allowed  to  remain  in  position  for  five  or  ten 
minutes,  or  until  pain  ceases.  As  soon  as  this  stage  has  arrived  the  opera- 
tion of  excavation  may  be  entered  upon.  It  is  best,  however,  to  remove 
the  excess  of  the  zinc  chloride  first  by  drying  with  bibulous  paper,  and 
then  to  irrigate  the  cavity  to  terminate  the  action  of  the  agent,  as  its 
strong  affinity  for  water  quickly  deprives  the  tissue  of  any  remaining 
portion.  Its  coagulating  effect  upon  albumin  prevents  it  from  penetrating 
to  any  considerable  depth,  and  therefore  makes  it  a  comparatively  safe 
remedy  to  employ  in  all  but  deep-seated  cavities,  or  when  the  pulp  is  nearly 
exposed. 

The  pain  is  often  intense  for  a  few  moments  after  the  introduction  of 
this  remedy  into  the  hypersensitive  cavity,  but  this  gradually  subsides, 
and  usually  in  a  few  minutes  entirely  passes  away.  If,  however,  the  pain 
continues,  it  maj  sometimes  be  controlled  by  the  application  of  heated  air, 
or  of  carbolic  acid,  or  of  both  combined.  Its  greatest  sphere  of  usefulness 
is  in  the  superficial  cavities  at  the  labio-  and  bucco- cervical  margins  of  the 
incisors,  cuspids,  and  bicuspids.  When  employing  it  in  the  approximal 
cavities  of  the  incisors,  especially  in  children  whose  age  would  indicate 
that  the  process  of  calcification  was  not  fully  completed,  caution  should 
be  exercised  not  to  cause  irritation  of  the  pulp,  as  the  cornua  in  these 
cases  often  lie  quite  near  to  the  surface. 

Occasionally  cases  will  be  found  in  which  this  agent  does  not  seem  to 
act  with  any  immediate  effect ;  but  if  the  excess  of  the  agent  be  removed 
with  bibulous  paper,  and  the  cavity  dried  as  thoroughly  as  may  be  by  this 
means,  and  then  closed  with  gutta-percha  or  zinc  oxyphosphate,  it  will  be 
found  that  in  two  or  three  days  the  carious  dentin  can  be  removed  without 
pain,  or  only  such  slight  sensations  as  are  readily  tolerated  by  the  patient.. 


192  OPERATIVE    DENTISTRY, 

Zinc  chloride,  to  be  most  efficient,  should  be  chemically  pure.  The 
fused  form  is  the  best,  and  this  should  be  liquefied  b}^  the  addition  of  just 
sufficient  distilled  water  to  produce  this  effect.  It  should  be  kept  in  a 
tightly  stoppered  bottle,  as  the  drug  has  such  an  affinity  for  water  that  it 
will  abstract  it  from  the  atmosi^here. 

Some  operators  prefer  to  obtain  the  obtunding  effect  of  the  zinc  chloride 
by  filling  the  cavities  with  zinc  oxychloride,  and  allowing  it  to  remain  for 
a  few  weeks,  when  the  hypersensitive  condition  will  have  been  greatly 
lessened  or  have  entirely  disappeared.  In  this  cement  there  is  usually  an 
excess  of  the  zinc  chloride  which  has  not  combined  with  the  oxide,  and 
as  a  consequence  it  is  free  to  act  upon  the  organic  matter  in  the  dentin. 
This  method  is,  however,  inadmissible  in  all  deep  cavities  in  vital  teeth, 
for  the  reasons  already  mentioned. 

Caustic  Potassa. — Caustic  potassa  combined  with  carbolic  acid  in 
equal  parts  (Robinson's  remedy)  often  serves  a  good  purpose  in  obtunding 
hypersensitive  dentin.  The  rubber  dam  should  be  applied  to  protect  the 
soft  tissues,  and  the  remedy  introduced  upon  a  pledget  of  cotton.  This 
often  causes  sharp,  stinging  pain,  which  usually  subsides  in  a  few  moments. 
Its  obtunding  action  is  increased  by  the  application  of  a  blast  of  heated  air. 

Chromic  acid  and  nitric  acid  have  both  been  recommended  as  obtundents 
of  hypersensitive  dentin.  Their  escharotic  action  is  so  great,  however,  as 
to  make  them  dangerous  agents  to  use,  while  their  decalcifying  effect  upon 
tooth  structure  is  so  strong  that  great  care  must  be  exercised  to  counteract 
this  effect  by  the  use  of  alkaline  solutions  immediately  afterwards.  The 
soft  tissues  should  be  protected  from  injury  by  the  rubber  dam,  and  the 
agents  introduced  into  the  cavity  by  means  of  a  platinum-  or  gold-pointed 
instrument.  These  agents  are  only  admissible  in  very  shallow  cavities, 
for  the  reasons  just  stated.  Chromic  acid  acts  by  coagulating  the  organic 
elements  of  the  dentin,  while  nitric  acid  decomposes  the  tissue. 

Silver  nitrate  is  used  for  obtunding  hypersensitiveness  of  the  dentin  in 
superficial  cavities  and  cervical  hypersensitiveness  resulting  from  recession 
of  the  gums,  but  it  is  not  admissible  except  in  the  posterior  portion  of  the 
mouth,  where  the  black  discoloration  produced  by  it  would  not  be  objec- 
tionable. Two,  and  sometimes  three,  applications  are  necessary  to  en- 
tirely obtund  the  sensation.  Moisture  should  be  excluded,  and  the  soft 
tissues  protected  during  its  application.  A  fifty  f)er  cent,  solution  of  the 
drug  is  applied  to  the  cavity  or  the  sensitive  part  of  the  tooth  upon  a 
pledget  of  cotton,  and  allowed  to  remain  in  contact  for  a  few  moments, 
after  which  the  excess  may  be  removed  with  bibulous  paper  and  the  parts 
irrigated  with  water. 

Local  anaesthesia  of  the  dentin  may  be  produced  by  ether  or  rigolene 
sprayed  upon  the  tooth,  but,  as  a  rule,  the  pain  produced  in  the  early 
stages  of  the  process  by  the  intense  cold  is  often  greater  than  the  pain  ex- 
perienced in  operating  uj)on  the  hypersensitive  dentin  in  its  original  state. 
The  danger  also  exists  in  treating  these  cases  by  this  means,  of  producing 
inflammation,  and  finally  devitalization  of  the  pulp  through  the  irritation 
of  such  severe  thermal  shock. 


CHAP  TEE   XIV. 

CATAPHORESIS. 

Cataphoresis,  electric  osmosis,  aud  electric  transfusion  are  terms 
which  have  been  applied  in  electrophysics  to  certain  phenomena,  by 
which  the  direct  or  galvanic  current  of  electricity  seems  to  convey  fluids 
and  chemical  substances  in  solution  through  animal  membranes  and  tissues, 
and  deposits  them  at  the  poles. 

The  physical  phenomena  of  natural  osmosis,  whereby  fluids  of  unequal 
density  pass  through  animal  membranes  and  tissues  in  a  direction  from 
the  lighter  to  the  denser  fluid,  illustrates  the  process  of  catai)horic  action. 
If  two  fluids  of  unequal  specific  gravity  be  separated  by  an  animal  mem- 
brane, and  the  positive  pole  or  anode  of  the  galvanic  current  conveying 
ten  to  fifteen  milliamperes  be  placed  in  one,  and  the  negative  pole  or 
cathode  in  the  other,  it  will  be  found  that  the  fluid  in  contact  with  the 
anode  will  rapidly  decrease  in  quantity,  while  that  in  contact  with  the 
cathode  will  be  increased  in  volume.  This  is,  however,  seemingly  some- 
thing more  than  simply  the  natural  x^hysical  phenomena  of  osmosis,  accel- 
erated by  the  action  of  the  electric  current,  for  the  direction  of  the  move- 
ment of  the  fluid  is  controlled  by  the  positive  current, — viz.,  it  flows  from 
the  positive  to  the  negative  pole.  But  if  the  current  be  reversed  the 
volume  of  the  fluid  is  changed  at  once  by  the  denser  fluid  being  carried 
into  the  partition  containing  the  lighter  fluid,  thus  reversing  the  estab- 
lished order  of  the  movement  of  fluids  in  natural  osmosis,  and  this  phe- 
nomenon may  be  produced  again  and  again  at  the  will  of  the  experi- 
menter. 

This  power  of  conveyance  of  chemic  elements  possessed  by  the  direct 
current  is  not  confined  to  substances  of  elementary  form,  but  may  in  many 
instances  be  applied  to  substances  of  very  complex  chemic  structure,  as, 
for  instance,  cocaine  (Cj^HjiI^Oj,  or  methyl-blue  (CigHigX.SCl) , which  may 
be  conveyed  as  molecules.  On  the  other  hand,  certain  chemic  substances 
may  be  conveyed  through  animal  membranes  and  tissues,  but  on  coming  in 
contact  with  the  opposite  pole  are  decomposed  by  the  electrolytic  action 
of  the  current  and  the  radicles  or  individual  elements  set  free. 

For  instance,  if  a  pellet  of  absorbent  cotton  saturated  with  a  neutral 
solution  of  ])otassium  iodide  (KI)  be  placed  upon  the  cathode,  another 
piece  of  cotton  soaked  in  distilled  water  be  placed  upon  the  anode,  a 
piece  of  animal  membrane,  like  chicken- skin,  be  placed  between  them  in 
contact  with  the  cotton  upon  each  electrode,  and  a  current  of  from  ten  to 
fifteen  milliamperes  be  made  to  pass  for  about  fifteen  minutes,  no  change 
will  be  noticed  at  the  cathodal  electrode,  but  the  cotton  at  the  anode  and 
the  surface  of  the  membrane  lying  in  contact  with  this  pole  will  be  found  to 
be  slightly  colored  with  iodine. 

13  193 


194  OPERATIVE    DENTISTRY. 

This  seems  to  prove,  Jirsf,  that  the  potassium  iodide  travels  under  the 
influence  of  the  direct  current  from  the  negative  to  the  positive  pole,  and 
secondly,  that  in  all  probability  this  chemic  compound  is  conveyed  through 
the  membrane  in  a  molecular  form  as  potassium  iodide,  and  upon  reaching 
the  anodal  electrode  is  decomposed  by  the  electrolytic  action  of  the  current, 
and  the  iodine  is  set  free.  On  the  other  hand,  if  the  potassium  iodide 
solution  be  placed  at  the  anodal  electrode,  the  cotton  at  the  cathode  be 
soaked  with  distilled  water  only,  and  a  current  be  turned  on  of  the  same 
strength  and  for  the  same  length  of  time,  no  change  will  be  observable  in 
the  color  of  the  cotton  at  the  cathode,  nor  of  the  cathodal  sui-face  of  the 
membrane,  while  at  the  anode  the  cotton  will  be  deeply  stained  with 
iodine. 

In  illustration  of  the  conveying  j)Ower  of  the  direct  current  applied  to 
the  more  complex  chemic  compounds,  cocaine  (Cj^H.^ioSTOJ  may  be  taken 
as  a  fair  sample  of  these  compounds. 

If  Si  four  per  cent,  solution  of  cocaine  hydrochlorate  be  placed  in  contact 
with  the  surface  of  the  skin  by  means  of  absorbent  cotton,  disks  of 
blotting-paper,  sponge,  or  other  absorbent  material,  it  will  have  little  or 
no  effect  in  obtunding  sensation,  although  it  may  be  kept  in  contact  for  an 
hour  or  more.  Let  this  same  solution,  however,  be  applied  in  the  same 
manner,  and  then  pass  a  direct  current  of  from  fifteen  to  twenty  milli- 
amperes  through  the  tissues,  the  anode  being  placed  in  contact  with  the 
substance  containing  the  cocaine  solution  and  the  cathode  at  some  other 
point,  the  cuticle  in  the  region  of  the  anode  will  in  a  very  short  time  be 
found  to  be  thoroughly  anaesthetic,  and  will  remain  in  this  condition  for 
from  several  minutes  to  as  many  hours,  the  period  of  anaesthesia  depending 
upon  the  strength  and  density  of  the  galvanic  current  employed,  the  dura- 
tion of  its  application,  and  the  per  cent,  of  the  cocaine  solution  which  had 
been  applied. 

Another  simple  experiment  illustrating  the  conveying  power  of  the 
direct  current  is  made  with  methyl-blue.  Take  two  open-mouthed  jars 
having  the  capacity  of  one  or  two  quarts.  Half  fill  each  of  these  jars  with 
distilled  water,  adding  a  small  quantity  of  methyl-blue,  sufficient  to  slightly 
tint  the  water.  Then  place  the  anode  in  one  jar  and  the  cathode  in  the 
other.  If  the  right  hand  be  now  immersed  in  one  jar  and  the  left  in 
the  other,  thus  completing  the  current,  and  be  permitted  to  remain  for 
twenty  ndnutes,  while  a  current  of  ten  to  fifteen  milliamperes  is  allowed 
to  pass  through  the  circuit,  it  will  be  found  at  the  expiration  of  this  period 
that  the  hand  which  had  been  placed  in  the  jar  with  the  anode  will  be 
deeply  stained  with  the  methyl-blue,  the  pigment  having  penetrated  the 
hair-follicles,  sweat-glands,  and  cutaneous  crevices,  producing  a  discolora- 
tion which  cannot  be  washed  away,  and  will  remain  for  several  days  ;  while 
the  hand  which  was  immersed  in  the  jar  containing  the  cathode  can  be 
readily  cleaned  by  a  simple  washing. 

When  this  peculiar  power  or  expression  of  electric  force  possessed  by 
the  direct  current  is  applied  to  therapeutics,  it  is  used  to  convey  medicinal 
substances  in  solution  which  have  been  placed  in  contact  with  the  positive 
electrode, — anode, — or  with  the  negative   electrode,— cathode,— into  the 


CATAPHOEESIS.  195 

tissues  of  the  body  or  through  them,  with  the  object  of  securing  the  local 
effect  of  such  remedial  agents. 

In  dental  surgery  this  may  be  applied  to  decolorizing  or  bleaching 
devitalized  teeth,  in  sterilizing  the  dentin,  or  producing  local  anaesthesia 
in  sensitive  dentin. 

The  power  of  the  galvanic  current,  however,  is  not  limited  to  the  con- 
veying of  medicinal  substances  in  solution,  but  it  may  be  employed  to 
transfer  substances  already  in  the  tissues,  whether  of  normal  or  abnormal 
comj)Osition,  from  one  part  of  the  body  to  another,  or  from  the  deeper 
tissues  within  any  part  of  the  body  to  the  surface,  with  the  object  of  en- 
tirely removing  such  substances. 

The  fluids  of  the  body  and  many  medicinal  substances,  when  subjected 
to  the  electrolytic  action  of  the  direct  current,  flow  in  a  constant  direction 
from  the  positive  to  the  negative  pole,  but  certain  other  chemical  sub- 
stances, which  may  be  dissolved  or  held  in  suspension  in  the  fluids  of  the 
body,  applied  to  the  surface,  have  been  found  to  travel  in  an  opposite 
direction, — viz.,  from  the  negative  to  the  positive  pole. 

At  the  present  time  the  subject  of  cataphoresis  is  still  more  or  less  in 
the  experimental  stage,  and  the  electric  affinity  or  direction  in  which  the 
various  medicinal  agents  will  travel  when  subjected  to  the  galvanic  current 
has  only  been  determined  for  a  few  of  them,  so  that  it  becomes  necessary 
to  establish  this  fact  by  experiment  for  each  new  remedy  used  before 
attempting  to  apply  it  cataphorically. 

The  phenomena  which  are  included  under  the  term  cataphoresis,  or 
electric  osmosis,  ' '  must  be  regarded  as  the  result  of  several  causes  oper- 
ating at  the  same  time  and  more  or  less  interdependent,  since  certain  of 
these  phenomena  are  electrolytic,  some  mechanical,  and  others  chemical."  * 

Most  physicists  explain  or  base  their  explanation  of  the  phenomena  of 
cataphoresis  upon  the  law  first  discovered  by  Thales  about  600  B.C., — 
viz.,  that  amber  when  briskly  rubbed  attracted  light  bodies  like  chaff 
and  bits  of  paper.  This  law  is  now  expressed  as  follows  :  ' '  When  a  dif- 
ference of  potential  is  established  by  a  direct  current  of  electricity  sent 
through  a  collection  of  molecules,  each  atom  or  molecule  of  any  substance 
that  is  free  to  move  deports  itself  according  as  the  electric  charge  which  it 
receives  is  j)ositive  or  negative.  Those  ions,  atoms,  or  molecules  with  a 
negative  charge  will  move  towards  the  anode,  and  those  with  a  positive 
charge  towards  the  cathode."  f 

The  direction,  therefore,  according  to  this  law,  in  which  a  remedy  in 
solution  will  be  conveyed  by  the  application  of  the  galvanic  current, 
whether  from  the  positive  to  the  negative  pole  or  the  reverse,  will  depend 
upon  the  electric  affinity  of  the  disassociated  ions,  or,  in  other  words,  upon 
the  initial  charge  which  they  have  received. 

There  is  a  question,  however,  in  the  minds  of  some  physicists  as  to 
whether  this  is  not  the  real  explanation  of  cataphoric  action,  rather  than 
that  the  current  by  its  electromotive  force  or  driving  power  forces  the 

*  Lectures,  National  School  of  Electricity, 
t  Ibid. 


196  operativp:  dentistry. 

remedy  in  solution  into  the  tissues,  as  was  generally  supposed  a  short 
time  ago. 

Among  the  chemical  substances  which  have  been  proved  upon  good 
authority  to  be  conveyed  into  the  tissues  when  applied  by  the  anodal 
electrode  of  the  galvanic  current  are  cocaine  hydrochlorate,  aconitine, 
tincture  of  aconite,  helleborine,  mercuric  chloride,  mercuric  succimide, 
lithium  chloride,  strychnia  nitrate,  strychnia  sulphate,  menthol,  and  thy- 
mol, while  sulphur,  eosine,  potassium  iodide,  and  the  bromide  salts  are 
conveyed  from  the  cathodal  electrode. 

Electrolysis. — Many  chemic  substances  and  comj)ouuds  are  decom- 
posed by  the  action  of  an  electric  current,  while  the  liberated  elements 
show  different  attractions,  some  of  them  travelling  to  the  positive  pole, 
others  to  the  negative. 

This  phenomenon  of  dissolution  is  denominated  electrolysis,  the  com- 
pound decomposed  or  acted  upon  an  electrolyte,  and  the  products  of  elec- 
trolysis are  termed  ions.  The  elements  thus  liberated  are  attracted  to  one  or 
the  other  of  the  poles  -,  those  which  are  attracted  to  the  positive  pole  are 
called  anions  ;  those  attracted  to  the  negative  pole  are  designated  cations. 

As  an  illustration  of  the  electrolytic  decomposition  of  chemic  substances 
the  familiar  experiment  of  decomposing  water  by  the  action  of  an  electric 
current  may  be  cited.  In  this  case  the  elements  composing  the  water  are  dis- 
associated, and  the  ions  immediately  seek  their  electric  attraction,  the  hydro- 
gen— which  is  a  cation  or  electropositive  element — collecting  in  the  form 
of  bubbles  at  the  negative  or  cathodal  electrode,  and  the  oxygen — an  anion 
or  electronegative  element — gathering  at  the  positive  or  anodal  electrode. 

In  carrying  this  phenomenon  a  step  farther  to  more  complex  chemic 
substances,  it  is  found  that  '■ '  by  passing  a  galvanic  current  from  a  primary 
battery  or  from  a  dynamo,  through  a  liquid  containing  a  metallic  salt  in 
solution,  such  as  nitrate  of  silver,  the  metallic  salt  is  decomposed,  the 
metal  being  deposited  upon  the  cathodal  electrode,  while  the  nitrogen 
enters  into  other  compounds,  as  with  oxygen,  forming  nitric  acid,  which 
accumulates  at  the  anodal  electrode."  * 

Decompositions  of  the  same  general  character  take  place  in  all  com- 
pound solutions,  regardless  of  their  degree  of  density,  whenever  they  are 
made  a  part  of  the  circuit  of  a  galvanic  current.  The  chemic  constitution 
of  such  solution  immediately  begins  to  undergo  electrolytic  dissolution ; 
the  acids,  oxygen,  chlorine,  and  the  electronegative  elements  collect 
about  the  positive  electrode,  while  the  alkalies,  hydrogen,  and  the  electro- 
positive elements  collect  about  the  negative  electrode. 

'•If  these  terminals  or  poles  in  contact  with  the  solution  are  suitably 
devised  electrodes,  and  the  solution  is  some  one  of  the  tissues  of  the  human 
body, — for  such  tissues,  though  differing  in  density,  are  bathed  in  liquids 
and  permeated  by  them, — physical  effects  similar  to  those  just  described 
follow  the  passage  of  the  current,  the  result  depending  upon  the  nature 
and  composition  of  the  tissues  involved,  the  strength  of  the  current,  and 
the  length  of  time  it  is  permitted  to  flow."  f 

*  Lectures,  National  School  of  Electricity.  f  Ibid. 


CATAPHORESIS.  197 

The  character  of  the  changes  which  take  place  in  the  electrolytes- 
fluids  or  animal  tissues — at  distant  points  from  the  electrodes  in  the  track 
of  the  current  is  not  known,  while  ''it  is  difficult  to  account  for  the  phe- 
nomena of  decomposition  which  takes  place  at  the  electrodes  without  as- 
suming that  some  kind  of  rearrangement  of  the  molecules  composing  the 
electrolytes  occurs  along  the  entire  track  of  the  current."  -'^ 

Anodal  Electrolysis. — This  term  is  used  to  designate  those  phenom- 
ena which  take  place  at  the  positive  pole,  or  anode,  as  a  result  of  the  appli- 
cation of  a  galvanic  current  to  or  its  passage  through  the  tissues  of  the 
living  human  body. 

Its  action  may  be  experimentally  shown  by  taking  a  piece  of  fresh,  lean 
meat  and  passing  a  needle  into  it  which  is  connected  with  the  positive 
pole  or  anode  of  a  galvanic  current  having  a  strength  of  from  five  to  ten 
milliamperes,  the  cathode  being  placed  upon  the  opposite  side.  After  the 
current  has  been  allowed  to  pass  for  a  few  minutes,  it  will  be  noticed  that 
at  the  point  of  insertion  of  the  needle  the  meat  has  become  dry,  white, 
and  shrunken.  The  extent  and  depth  to  which  this  effect  may  be  carried 
into  the  tissue  will  depend  upon  the  strength  of  the  current,  the  length  of  time 
it  is  employed,  and  its  density,  the  latter  being  determined  by  the  size  of 
the  needle  or  anodal  electrode.  This  effect  in  a  measure  is  the  result  of 
the  coagnlation  of  the  albuminoid  substances  contained  in  the  tissues  from 
the  action  of  the  acids  collected  at  the  anode,  and  partly  to  cataphoresis, 
or  the  electric  affinity  of  ions  possessing  an  electropositive  charge,  which 
directs  them  to  the  cathodal  electrode. 

If  the  needle  or  anode  is  made  of  a  material  that  is  not  readily  oxidized 
— like  gold  or  platinum— and  is  not  materially  acted  upon  by  acids  or 
chlorine,  no  change  other  than  that  just  mentioned  is  observable  in  the 
tissues ;  but  if  the  needle  employed  is  of  iron,  steel,  or  copper,  salts  are 
formed,  and  the  tissues  in  its  immediate  vicinity  are  stained  by  a  deposit 
of  the  oxide  or  oxychloride  of  the  metal  used. 

The  drying  of  the  tissues  in  the  vicinity  of  the  anode  is  due  to 
the  cataphoric  effect  of  the  current  which  carries  the  fluids  towards 
the  cathode,  or  to  the  migration  of  electropositive  ions  which  seek  their 
affinity  at  the  negative  pole.  This  phenomenon  may  be  illustrated  by 
passing  a  galvanic  current  through  a  piece  of  wet  clay.  In  a  few 
minutes  the  surface  of  the  clay  in  the  vicinity  of  the  anode  will  begin 
to  show  signs  of  drying  and  hardening,  while  at  the  cathode  the  mois- 
ture will  collect  in  increasing  quantity  and  softening  of  the  surface  take 
place. 

It  may  be  stated  briefly,  therefore,  that  the  effect  of  anodal  electrolysis 
upon  animal  tissue  is  destructive,  but  that  this  destructive  action  may 
be  employed  to  advantage  in  the  treatment  of  various  pathologic  con- 
ditions where  this  destructive  effect,  if  judiciously  used,  would  retard  or 
entirely  arrest  the  progress  of  the  diseased  condition. 

The  phenomena  of  anodal  electrolysis  which  takes  place  in  animal 
tissues  are  : 


*  Lectures,  National  School  of  Electricity. 


198  OPERATIVE    DENTISTRY. 

1.  The  accumulation  of  oxygen,  chlorine,  and  acids  in  the  vicinity  of  the 
electrode. 

2.  The  tissues  in  contact  with  and  immediately  surrounding  the  elec- 
trode, as  the  result  of  the  accumulation  of  the  above  destructive  anions, 
suffer  more  or  less  disintegration  by  the  disturbance  of  their  molecular 
composition,  which  later  causes  structural  changes  and  arrest  of  function. 

3.  The  acids  formed  at  the  anode,  reacting  upon  the  albuminoid  sub- 
stances and  other  organic  elements  contained  in  the  tissues,  produce  astrin- 
gent, styptic,  Meaching,  and  coagulating  effects  upon  those  parts  with  which 
they  come  in  contact. 

4.  When  the  electrode  is  made  of  some  material  which  is  readily 
oxidized,  or  has  a  strong  affinity  for  the  acids  which  collect  about  it, 
secondary  chemical  compounds  are  formed,  like  oxide  or  chloride  of  iron,  of 
copper,  or  of  zinc,  as  the  case  may  be,  which  may  possess  therapeutic 
value  or  may  produce  indelible  staining  of  the  tissues. 

The  therapeutic  employment  of  the  secondary  products  formed  at  the 
anode  or  cathode  is  termed  metallic  electrolysis,  but  this  function  is  almost 
exclusively  confined  to  the  anode. 

Anodal  electrolysis  has  a  wide  range  of  theraj)eutic  application  in  both 
general  and  special  surgery.  In  dental  surgery  and  stomatology  it  may  be 
applied  to  the  removal  of  cysts  and  new  growths  upon  the  tongue  or  oral 
mucous  membrane ;  to  hemorrhagic  conditions  of  this  membrane,  and  in 
hemorrhage  after  extraction  ;  to  phagedenic  ulcers,  follicular  diseases,  and 
inflammatory  conditions  due  to  low  forms  of  bacterial  life ;  to  the  local 
treatment  of  pyorrhoea  alveolaris ;  to  the  production  of  aseptic  conditions 
in  devitalized  and  suppurating  teeth,  and  to  decolorizing  or  bleaching  de- 
vitalized teeth. 

Cathodal  Electrolysis. — This  term  is  used  to  designate  those  phe- 
nomena which  take  place  at  the  negative  ])ole  or  cathode  as  a  result  of  the 
application  of  a  galvanic  current  to  the  tissues  of  the  body.  When  such 
a  current  is  x>assed  through  the  compound  solutions  which  compose  a 
larger  part  of  every  animal  tissue,  the  constituents  -of  the  tissues  in  the 
immediate*  vicinity  of  the  cathode  are  decomposed,  the  hydrogen  and  the 
alkali  ions  gathering  about  the  cathodal  electrode.  The  alkalies  which  are 
thus  collected  are  principally  soda  and  potassa. 

Inasmuch  as  these  substances  do  not  jDOSsess  chemic  affinity  for  the  metals 
generally  used  for  electrodes,  with  perhaps  the  exception  of  aluminum, 
which  is  corroded  by  the  alkali  ions,  forming  aluminates  of  soda  and 
potassa,  but  which  do  not  seem  to  possess  any  therapeutic  value  when 
locally  applied,  it  only  becomes  necessary  to  consider  the  action  and  dis- 
l^osition  of  the  hydrogen  and  the  alkalies.  If  a  piece  of  fresh  meat  or  egg 
albumin  be  subjected  to  the  action  of  a  galvanic  current,  it  will  be  ob- 
served that  the  hydrogen  gas  which  collects  at  the  cathode  will  bubble  up 
and  escape,  or  be  detained  in  the  meshes  of  the  tissues,  while  the  soda  and 
potassa  will  unite  with  the  albuminoids  of  the  tissues  immediately  sur- 
rounding the  cathodal  electrode,  causing  softening  of  these  tissues,  and  if 
continued  for  a  sufficient  period  of  time  in  the  living  body,  disintegration, 
loss  of  vitality,  structural  changes,  and  liquefaction  will  take  place. 


CATAPHORESIS.  199 

The  phenomena  j)resented  by  cathodal  electrolysis,  therefore,  are  : 

1.  The  accumulation  of  hydrogen  and  alkalies  in  the  vicinity  of  the 
electrode. 

2.  The  presence  of  hydrogen  gas  in  the  meshes  of  the  tissues  or  its  escape, 
and  the  union  of  the  alkalies  with  the  albuminoids  of  the  tissues. 

3.  The  softening  of  the  tissues  in  the  neighborhood  of  the  electrode  and 
their  final  liquefaction. 

From  the  foregoing-  statements  it  will  be  observed  that  the  phenomena 
of  cathodal  electrolysis  are  also  destructive  in  their  nature  to  the  living 
tissues  when  much  prolonged,  and  yet  these  phenomena  when  skilfully 
applied  to  certain  pathologic  conditions  are  capable  of  being  rendered 
most  beneficial. 

Cathodal  electrolysis  has  its  greatest  usefulness  in  the  softening  and  re- 
laxation of  cicatricial  tissue,  in  the  reduction  of  hyperplasias  and  other 
inflammatory  growths,  in  the  removal  of  fungous  growths,  and  in  the 
treatment  of  bony  and  cartilaginous  enlargements,  especially  of  the  nasal 
passages,  the  alveolar  processes,  and  the  palate. 

Ordinarily  the  electromotive  force  required  for  electrolytic  work  will 
not  exceed  twenty  volts,  but  the  resistance  of  the  tissues  is  so  variable 
that  a  current  of  the  strength  of  ten  to  fifteen  milliamperes  is  not  infre- 
quently employed,  making  a  greater  electromotive  force  necessary  for  the 
most  efficient  work. 

THE    GENERAL   PRINCIPLES   OR    LAWS    WHICH    GOVERN    THE    GENERATION 
AND   TRANSMISSION   OF   ELECTRICITY, 

Generation. — Electricity  may  be  generated,  first,  by  friction,  when  it 
is  termed  frictional  or  static  electricity  ;  secondly,  by  chemic  action,  when  it  is 
termed  chemic  electricity  ;  thirdly,  by  induction,  when  it  is  known  as  induced 
electricity. 

ThQ  first  is  a  form  of  electricity  used  largely  in  medicinal  practice,  and 
is  generated  by  a  machine  in  which  a  glass  disk  is  made  to  revolve  rapidly 
while  in  contact  with  specially  prepared  rubbers,  the  electricity  being  col- 
lected and  stored  by  apparatus  adapted  to  the  purpose. 

The  second  or  chemic  electricity  is  generated  by  primary  or  galvanic 
batteries. 

Primary  batteries,  of  which  there  are  a  number  of  different  forms,  are 
composed  of  two  plates  of  different  metals, —^/ie  elements, — as  copj)er  and 
zinc,  or  of  one  metal  and  a  non-metallic  substance,  as  carbon,  which  are 
placed  in  ajar  containing  a  liquid — the  electrolyte — composed  of  a  solution 
of  sulphuric  acid  or  of  ammonium  chloride,  zinc  chloride,  or  other  suitable 
solution,  the  two  plates  being  connected  together  outside  of  the  liquid, 
when,  by  the  chemic  action  taking  j)lace  between  the  elements  and  the 
electrolyte,  a  current  of  electricity  is  generated.  This  constitutes  a  cell 
of  a  primary  or  galvanic  battery.  A  battery  may  be  composed  of  a  single 
cell  or  any  number  of  cells  joined  together  in  series  by  connecting  with 
copper  wire  the  negative  pole  of  one  cell  to  the  positive  pole  of  the  next, 
and  so  on  until  the  series  is  completed.  The  wire  or  cord  attached  to  the 
copper  element  of  the  first  cell  would  be  the  xmsitive  pole,   while  that 


200  OPERATIVE    DENTISTRY. 

attached  to  the  zinc  element  of  the  last  cell  would  be  the  negative  pole. 
The  current  travels  in  the  outside  circuit  from  the  jjositive  to  the  negative 
pole.  The  poles  are  determined  by  the  direction  in  which  the  current 
flows ;  the  plate  from  which  the  electric  current  flows  outside  the  liquid  is 
termed  the  positive  pole,  while  the  plate  to  which  the  current  returns  out- 
side the  liquid  is  denominated  the  negative  pole.  In  a  cell  composed  of 
copper  and  zinc  elements,  with  dilute  sulphuric  acid  as  the  electrolyte,  the 
zinc  is  most  violently  acted  upon,  and  the  electric  current  generated  flows 
from  the  zinc  or  positive  element  through  the  liquid  to  the  copper  or  negative 
element,  and  from  that  through  the  external  conductors  or  wires  back  to  the 
zinc  element,  thus  completing  a  circuit.  That  portion  of  the  zinc  plate  which 
is  immersed  in  the  electrolyte  is  positive  to  that  part  of  the  copper  plate 
which  is  likewise  immersed,  but  the  portion  of  the  copper  plate  above  the 
liquid  is  positive,  while  the  same  portion  of  the  zinc  plate  is  negative. 
To  indicate  these  conditions  the  signs  plus  (+)  and  minus  ( — )  are  used. 

Primary  batteries  are  divided  into  two  classes, — viz.,  open  circuit  and 
closed  circuit  batteries.  The  open  circuit  battery  is  one  which  works  best 
when  not  in  constant  use,  and  is  usually  employed  for  call-bells  and  signal 
circuits  generally.  The  ^ '  Leclanche' '  is  the  best  of  this  class  of  batteries. 
In  this  the  elements  used  are  zinc  and  carbon ;  the  electrolyte  is  a  solution 
of  ammonium  chloride  ;  the  carbon,  being  placed  in  a  porous  jar  and  sur- 
rounded by  powdered  manganese  dioxide,  is  suspended  in  the  liquid  in 
the  centre  of  the  battery  jar,  and  the  zinc  element  is  suspended  at  one  side. 
This  form  of  battery,  if  made  to  work  continuously,  soon  runs  down,  and 
must  be  given  a  period  of  rest  before  it  can  be  used  again.  When  only 
brought  into  action  for  brief  x)eriods  at  a  time  it  works  most  satisfactorily. 
The  electromotive  force  of  such  a  cell  is  about  1.47  volts. 

The  class  of  batteries  known  as  closed  circuit  batteries  comprise  those 
varieties  which  work  best  when  in  constant  service.  The  "gravity" 
battery,  which  is  a  modification  of  the  "Daniell,"  is  the  best  of  this  class. 

The  gravity  battery  is  formed  by  placing  the  copper  element  in  the 
bottom  of  the  battery  jar  and  suspending  the  zinc  element  from  the  top  ; 
these  are  cast  in  the  form  of  a  wheel  or  "  crowfoot."  A  cupric  sulphate 
solution  is  then  poured  over  the  copper  element,  and  a  quantity  of  cupric 
sulphate  crystals  added.  Upon  this  solution  is  carefully  poured  a  solution 
of  zinc  sulphate.  The  specific  gravity  of  the  two  solutions  is  so  different 
that  they  do  not  readily  mix  ;  the  cupric  sulphate  solution,  being  the 
heavier,  remains  at  the  bottom  of  the  jar.  The  zinc  sulphate  solution  takes 
the  place  of  the  sulphuric  acid  in  the  Dauiell'  s  cell,  and  although  it  does 
not  give  quite  so  high  a  voltage,  the  action  of  the  cell  is  more  even 
and  constant.     The  potential  of  such  a  cell  is  from  1  to  1.14  volts. 

The  dry  cell  battery  is  made  either  upon  the  principle  of  Zamboni'  s  dry 
voltaic  pile,  or  some  such  substance  as  sand,  sawdust,  or  paper,  moistened 
with  acidulated  water,  separates  the  elements  in  each  cell. 

Secondary  or  storage  batteries  are  composed  of  two  or  more  plates  of  the 
same  metal, — generally  lead, — which  are  placed  in  a  solution  which,  under 
ordinary  circumstances,  does  not  attack  the  metal, — usually  dilute  sulphuric 
acid, — and  consequently  no  electricity  is  generated.     But  if  a  current  of 


CATAPHORESIS.  201 

electricity,  generated  from  some  outside  source,  like  a  dynamo  furnishing 
a  one-hundred-and-ten-volt  electric  lighting  current,  is  allowed  to  pass 
through  the  battery,  a  chemic  action  is  set  up  in  the  solution  termed 
charging^  which  decomposes  it  and  causes  plumbic  dioxide  (PbO,)  to  be  de- 
posited upon  one  plate  and  metallic  plumbum  (Pb)  in  a  spongy  form  upon 
the  other.  This  forms  a  battery  of  two  different  elements, — viz.,  PbO^ 
and  Pb  immersed  in  an  electrolyte,  hydric  sulphate  (H.SOJ — sulphuric 
acid — of  full  strength  and  specific  gravity,  which  is  capable  of  acting 
upon  them. 

The  lead  plates  which  form  the  element  must  be  so  constructed  as  to 
present  a  large  surface  upon  which  the  chemic  action  may  take  place,  as 
the  amount  of  energy  which  can  be  stored  in  a  cell  depends  upon  the 
capability  of  the  plates  to  appropriate  the  results  of  the  chemic  action. 

If  the  poles  of  the  battery  are  now  brought  together  and  the  circuit 
closed,  a  current  of  electricity  will  be  immediately  generated.  In  the 
chemic  action  which  takes  place  during  the  discharge  of  the  battery,  one 
atom  of  oxygen  (O)  contained  in  each  molecule  of  the  PbO^  will  pass  to 
the  opposite  plate,  joining  with  the  Pb  and  forming  plimibie  oxide  (PbO). 
This  process  continues  as  long  as  any  molecule  of  PbO^  remains  upon  the 
surface  of  the  plate  to  give  up  its  oxygen.  When  no  more  oxygen  is 
liberated  both  plates  become  alike  (PbO)  over  the  entire  surface. 

The  sulphur  radical  in  the  electrolyte  (H^SOJ  enters  into  combination 
with  the  active  material  on  both  plates,  forming  plumbic  sulphate  (Pb^SOJ, 
the  specific  gravity  of  the  electrolyte  being  correspondingly  reduced. 
When  all  of  the  active  material  has  been  changed  in  this  manner  the  cell 
is  said  to  be  discharged,  for  an  equilibrium  has  been  created  between  the 
two  plates  and  the  electromotive  force  is  reduced  to  zero,  and  so  remains 
until  it  is  again  charged  by  an  electric  current  from  the  outside.  Secondary 
batteries  discharge  their  electric  current  in  an  opposite  direction  from  that 
in  which  they  were  charged.  Like  primary  batteries,  the  potential  or 
electromotive  force  does  not  depend  so  much  upon  the  size  of  the  elements 
as  upon  the  materials  composing  them  and  the  nature  of  the  electrolyte  ; 
but  the  amount  of  the  electric  energy  furnished  by  any  cell  will  depend 
upon  the  area  of  the  surfaces  of  the  elements  exposed  to  the  action  of  the 
electrolyte. 

The  electromotive  force  of  the  charging  current  should  be  about  twice 
as  high  as  that  of  the  cells  to  be  charged.  On  the  other  hand,  the  amount 
of  current  charged  per  hour  should  not  exceed  what  is  called  the  normal 
charging  rate,  and  which  differs  according  to  the  size  of  the  cells.  The 
normal  rate  of  charge  for  small  storage  batteries  is  about  ten  hours,  and 
if  a  cell  has  a  capacity  of  fifty  ampere  hours,  not  more  than  five  amjDeres 
should  be  charged,  and  for  a  cell  of  one  hundred  ampere  hours,  not  more 
than  ten  amperes  should  be  charged. 

The  rate  of  charge  should  be  preferably  kept  at  normal  or  under,  as 
continuous  charging  at  a  higher  rate  than  normal  would  injure  the 
plates. 

Storage  batteries,  however,  have  never  come  into  general  use  for  medi- 
cal or  dental  purposes,  and  although  they  have  been  used  to  some  extent 


202  OPERATIVE    DENTISTRY. 

for  heating  cauteries  and  lighting  exploring  lamps,  they  are  by  no  means 
a  convenient  or  economical  method  of  obtaining  an  electric  current. 

Induced  Electricity. — This  form  of  electric  current  is  produced  by 
dynamo-electric  machines,  and  is  the  common  current  now  used  so  exten- 
sively for  illuminating  and  power  purposes.  There  are  two  general  classes 
of  dynamo -electric  machines ;  one  class  produces  an  alternating  current^ 
and  the  other  a  continuous  current. 

The  modern  Edison  dynamo-electric  machine  so  generally  used  all  over 
the  world  for  lighting  houses  and  shops  and  running  small  motors 
delivers  a  continuous  current.  This  current  is  often  used  for  thera- 
peutic purposes  by  the  physician,  surgeon,  and  dentist.  The  current 
delivered  by  such  a  dynamo  differs  from  that  delivered  from  the  primary 
battery  in  that  it  has  a  slight  but  uniform  variation  in  strength.  The 
strength  of  the  current  coming  from  a  primary  battery  may  be  represented 
by  a  straight  line,  while  that  from  the  dynamo  would  be  by  comparison 
represented  by  a  line  waving  slightly  but  uniformly.  It  has  not  been 
definitely  determined  whether  this  difference  in  the  current  has  any  effect 
upon  the  constituents  of  the  body,  but  so  far  as  known  they  seem  to  act 
alike. 

The  most  convenient  dynamo  current  for  therapeutic  uses  is  the  Edison 
direct  current  of  one  hundred  and  ten  volts.  The  pressure  of  this  current 
varies  from  one  hundred  to  one  hundred  and  twenty-five  volts,  according 
to  the  position  on  the  mains.  The  electromotive  force  can  be  reduced  to 
any  degree  necessary  to  conform  with  the  requirements  of  the  physician, 
the  surgeon,  or  the  dentist  by  lami3S  or  other  resistances  and  shunts.  By 
employing  this  form  of  current  much  of  the  annoyance  attending  the 
operation  of  primary  batteries  is  obviated,  and  with  the  now  quite  com- 
mon practice  of  placing  the  mains  in  underground  conduits,  the  dangers 
from  lightning  or  crossing  with  wires  of  dangerous  potential  is  reduced 
almost  to  nil. 

Transmission. — Electric  currents  are  transmitted,  conveyed,  or  con- 
ducted by  various  substances,  like  metals,  charcoal,  graphite,  fluids,  ani- 
mal tissues,  etc.  Any  substance  which  is  capable  of  conveying  electricity 
is  termed  a  conductor,  and  those  substances  which  do  not  convey  it  are 
termed  non-conductors  ;  dry  air,  glass,  vulcanized  rubber,  porcelain,  etc., 
belong  to  the  latter  classification. 

In  substances  which  are  i^erfect  conductors,  like  silver  and  copper, 
electricity  moves  with  absolute  freedom  under  any  electromotive  force,  no 
matter  how  small.  Copper  wire  is  generally  used  as  a  means  of  conduct- 
ing electric  currents. 

The  conducting  power  of  pure  silver  is  100,  that  of  copper  97.  In 
substances  which  are  perfect  non-conductors,  electricity  will  not  move 
under  any  electromotive  force,  no  matter  how  great.  In  substances  which 
are  imperfect  or  partial  conductors,  electricity  moves  only  upon  the  exhi- 
bition of  great  electromotive  force,  the  amount  of  electromotive  force 
required  varying  according  to  the  ability  of  the  substance  to  convey  an 
electric  current. 

The  transmission  of  electric  currents  is  through  metallic  conductors, 


CATAPHORESIS.  203 

copper  wire  being  choseu  for  econoDiic  reasons.  The  resistance  of  these 
conductors  is  varied  by  the  character  of  the  metal,  the  cross-section  (size), 
and  the  distance  to  which  the  current  is  conveyed. 

The  percentage  of  conducting  power  possessed  by  the  various  metals 
and  alloys  employed  in  electric  work  is  as  follows  :  Silver,  100  ;  cojDper, 
97  ;  gold,  75  ;  aluminum,  54  ;  zinc,  28 ;  platinum,  17  ;  wrought  iron,  16  ; 
nickel,  12  -,  tin,  12  ;  lead,  8  ;  mercury,  1.6  ;  cast  iron,  3  ;  platinum  silver 
made  of  two  parts  platinum  and  one  part  silver,  6.4  ;  German  silver  made 
of  five  and  one-half  parts  copper,  two  parts  zinc,  and  two  and  one-half 
parts  nickel,  3.5 ;  German  silver  made  of  six  parts  copper,  two  and  one- 
half  parts  zinc,  and  one  and  one-half  parts  nickel,  5  ;  German  silver  made 
of  five  parts  copper,  three  and  one-half  parts  zinc,  and  one  and  one- 
quarter  parts  nickel,  7. 5. 

Units  of  Measurement. — The  electromotive  force,  or  electric  pressure 
furnished  by  the  cell  or  the  dynamo,  is  the  force  which  moves  the  current 
against  the  resistance  of  imperfectly  conducting  substances,  and  is  termed 
voltage. 

The  active  eney^gy  of  electricity  lies  in  a  property  designated  as  its  ciir- 
rent  strength,  and  is  termed  its  amperage. 

The  unit  of  quantity  is  the  coulomb. 

The  unit  of  pressure  is  the  volt. 

The  unit  of  strength  is  the  ampere. 

The  unit  of  resistance  is  the  ohm. 

The  unit  of  poioer  is  the  ivott. 

A  coulomh  represents  the  quantity  of  electricity  that  passes  during  one 
second  through  a  conductor  having  a  resistance  of  one  ohm,  with  one  volt 
of  electromotive  force. 

A  volt  re  J)  resents  the  electromotive  force  (E.  M.  F.)  which  is  required 
to  move  one  amj)ere  of  current  through  one  ohm  of  resistance.  This  force 
may  be  represented,  for  example,  by  the  pressure  necessary  to  move  a  cer- 
tain number  of  gallons  of  water  per  minute  through  a  pipe  of  given  size  ; 
reduce  the  size  of  the  pipe  and  the  resistance  becomes  greater,  thus  call- 
ing for  a  greater  degree  of  pressure  to  accomplish  the  task. 

An  ampere  represents  the  volume  of  an  electric  current  carrying  one 
coulomb  per  second ;  hence  it  is  the  measure  of  the  rate  of  floiv  of  an 
electric  current,  and,  in  connection  with  the  voltage,  measures  the  energy  of 
the  current. 

The  measurement  of  the  ampere  of  current  is  based  upon  the  electro- 
chemical effects  of  currents,  and  is  defined  as  that  much  current  which 
will  deposit  silver  at  the  rate  of  0.0001118  grammes  per  second  from  a 
standard  solution  of  silver  nitrate  in  water,  or  which  will  decompose 
0.00326  milligramme  of  water  in  one  second. 

An  ohm  of  resistance  is  defined  as  equal  to  the  resistance  of  a  column 
of  pure  mercury  which  is  106.3  centimetres  long,  and  has  a  uniform  cross- 
section  which  contains  14.4521  grammes  of  mercury,  the  temperature  being 
that  of  melting  ice.  This  gives  the  column  the  uniform  cross-section  of 
one  square  millimetre.  The  ohm  is  that  degree  of  resistance  which  will 
allow  one  ampere  of  current  to  pass  under  a  pressure  of  one  volt. 


204  OPERATIVE    DENTISTRY. 

According  to  Ohtii's  law,  when  a  current  of  electricity  flows  through  a 

wire,  under  the  pressure  from  a  battery  or  other  sources  of  electricity, 

the  effective  strength  of  current  ivMch  flows  in  the  circuit  is  equal  to  the  pressure 

E 
divided  by  the  resistance  of  the  circuit.    It  is  often  written  thus  :  C  =  ^5^,  when 

Jtv 

C,  E,  and  R  stand  for  current  pressure  (electromotive  force)  and  resistance, 
and  may  be  read  C  equals  E  divided  by  E.  It  is  evident,  also,  from  the 
relation  as  written  above,  that  E  equal  C  times  E,  and  E.  equals  E  divided 
by  C.  By  this  law  if  any  two  out  of  the  three  fundamental  electric  quan- 
tities which  exist  in  a  circuit  are  known,  the  third  can  at  once  be  calcu- 
lated. Thus,  if  a  sixteen-candle-power  incandescent  lamp  is  known  to 
take  one-half  an  ampere  when  attached  to  a  circuit  which  furnishes  a 
current  at  a  pressure  of  one  hundred  and  ten  volts,  the  resistance  of  the 
lamp  when  in  operation  may  be  calculated  at  once  to  be  one  hundred  and 
ten  divided  by  one-half,  which  gives  the  resistance  of  two  hundred  and 
twenty  ohms.  Or  if  two  cells  of  a  battery,  each  furnishing  a  iDressure  of 
1.1  volts,  and  each  having  an  internal  resistance  of  three  ohms,  be  con- 
nected with  an  external  circuit  of  2.8  ohms'  resistance,  then  the  total  resist- 
ance in  the  circuit  is  8.8  ohms,  and  the  pressure  which  acts  to  pass  the 
current  through  the  circuit  is  2.2  volts.  The  current  flowing  under  these 
circumstances  is  therefore  one-quarter  ampere  (C  ^  E  E  or  \  =  2.2/8.8). 

A  watt  is  the  amount  of  power  developed  by  a  current  of  one  ampere, 
having  an  electromotive  force  of  one  volt.  It  is  the  unit  of  electric  worTc, 
and  represents  the  poiver  exerted  by  one  ampere  of  current  at  one  volt  of 
pressure- 

These  propositions  may  be  written  thus  : 


Amperes  =  volts  -^  ohms. 
Ohms  ^  volts  -H  amperes. 
Volts  =  amperes  X  ohms. 
Watts  =  volts  X  amperes. 


RHEOSTATS  ;    CURRENT  SELECTORS  ;    CURRENT  CONTROLLERS. 

Rheostats. — Electric  currents  furnished  by  the  various  means  already 
mentioned — viz., primary  batteries,  secondary  batteries,  and  dynamos— need 
to  be  modified  in  strength  in  order  to  adapt  them  to  the  requirements  of 
therapeutics.  This  may  be  accomplished  by  adding  resistance  to  the  ex- 
ternal current,  or  by  diverting  a  portion  only  of  the  available  current  into 
the  circuit  with  the  patient. 

The  substances  which  are  introduced  for  the  purpose  of  reducing  the 
energy  of  the  current  by  the  interposition  of  increased  resistance  are 
selected  because  of  their  great  resistance  to  the  passage  of  electric  cur- 
rents. These  substances  are  water,  carbon,  graphite,  and  coils  of  German 
silver  wire. 

Eheostats  when  constructed  for  therapeutic  work  have  a  mechanical 
device  for  increasing  and  decreasing,  at  the  will  of  the  operator,  the 
amount  of  resisting  substance  in  the  circuit. 

Water  Rheostats. — Water  rheostats  vary  in  resisting  capacity  accord- 
ing to  the  quantity  and  purity  of  the  fluid  admitted  into  the  circuit.    Dis- 


CATAPHORESIS. 


205 


tilled  water  only  should  be  used  for  such  purpose.  The  current  in  passing 
through  this  resistance  heats  the  water  and  decomposes  or  electrolyzes  it. 
If  the  water  is  impure,  deposits  occur  or  the  metal  i)lates  may  be  corroded, 
thus  impairing  the  usefulness  of  the  instrument.  The  chief  objection  to 
this  form  of  rheostat  is  the  fact  that  there  is  no  simple  or  elementary 
means  of  measuring  with  accuracy  such  form  of  resistance. 

In  the  water  rheostat  one  pole  is  attached  to  two  metal  plates  separated 
by  about  three-fourths  of  an  inch  and  placed  in  the  bottom  of  the  glass 
receptacle  containing  the  w^ater.  The  other  pole  is  attached  to  a  sliding 
rod  worked  with  a  ratchet,  the  rod  having  attached  to  its  lower  end  an 
angular  plate  of  metal  with  the  apex  iDointing  downward, — both  poles 
should  be  made  of  platinum, — which,  as  it  is  lowered  into  the  water, 
increases  the  surface  of  this  pole  in  contact  with  the  water,  and  thus  de- 
creases the  resistance.  The  current  passes  from  the  battery — or  a  suitable 
lamp  resistance  or  shunt  when  the  street  main  is  used — through  the  water 
and  the  patient  in  series.  The  current  is  controlled  by  raising  or  lower- 
ing the  pole  having  the  angular  plate  of  metal  attached  to  its  lower  end. 

Carbon  and  Graphite  Rheostats. — This  form  of  rheostat  is  usually 
constructed  in  the  shape  of  a  broken  ring,  one  pole  being  attached  to  one 
end  of  the  ring,  and  the  other  pole  to  the  index  which  travels  over  the 
circular  disk  (Fig.  316).     These  serve  fairly  well  for  modifying  the  cur- 

FiG.  316. 


Jewell  graphite  rheostat. 

rents  from  portable  and  stationary  batteries,  and  also  from  dynamos  when 
the  amount  of  current  used  is  small.  They  have  the  advantage  of  fur- 
nishing a  high  resistance  in  a  very  small  compass,  but  they  also  have  a 
disadvantage  in  that  they  cannot  be  graduated,  since  their  resistance  is 
variable  even  in  instruments  of  the  same  size  and  shape. 

German  Silver  "Wire  Rheostats. — German  silver  wire  rheostats 
when  well  made  are  the  most  reliable  and  constant,  and  have  this  advan- 
tage over  all  other  forms,  that  the  resistance  which  they  offer  can  be  accu- 
rately measured.  In  this  form  of  rheostat  the  degree  of  resistance  is 
regulated  by  the  length  and  the  diameter  of  the  wire,  the  cross-section 
being  reduced  to  the  smallest  size  which  will  conduct  the  current  without 
overheating  ;  it  is  therefore  graded  with  especial  reference  to  the  amper- 


20G  OPERATIVE    DENTISTRY. 

age  of  the  current  it  is  expected  to  convey.  In  the  construction  of  this 
form  of  rheostat  two  general  methods  are  followed  :  one  is  to  arrange  the 
wire  in  unbroken  coils  between  a  certain  number  of  contact  points,  dis- 
posed at  equal  distances  from  each  other  around  a  broken  ring,  one  pole 
attached  to  one  end  of  the  broken  ring,  as  in  the  graphite  rheostat,  and  the 
other  pole  to  the  index  which  travels  over  the  contact  point.  The  other 
method  is  to  wind  the  wire  upon  spools  of  fibre,  one  arranged  as  a  per- 
manent resistance,  the  other  as  a  shunt  i-esistance.  The  coil  of  the  shunt 
resistance  is  wound  in  notches  of  a  small  fraction  of  an  inch,  and  a  con- 
tact-shoe is  made  to  move  from  one  end  of  the  coil  to  the  other,  and  in 
doing  so  touches  several  hundred  turns  of  the  wire,  thus  giving  as  many 
different  gradations  of  current  flow. 

In  the  use  of  high  voltage  currents,  such  as  the  one-hundred-aud-ten- 
volt  circuit,  it  may  be  switched  through  the  coils  of  such  a  rheostat  and 
reduced  to  any  degree  required. 

A  cuiTent  selector  is  a  mechanical  device  for  throwing  a  greater  or  less 
number  of  cells  of  a  primary  or  secondary  battery  into  the  circuit.  The 
amount  of  current  can  thus  be  made  to  vary  as  the  exigencies  of  the  case 
demand,  while  the  electromotive  force  is  gradually  increased  and  decreased 
at  the  will  of  the  operator. 

A  current  selector  or  switch  of  this  character  does  not,  however,  do 
away  with  the  necessity  of  a  rheostat,  especially  if  it  is  constructed  to  in- 
crease the  number  of  cells  thrown  into  the  circuit  by  groups  rather  than 
singly. 

Dynamo  Current  Controllers. — These  are  resistances  especially 
adapted  to  the  dynamo  current,  either  to  be  put  in  series  with  the  patient 
or  so  constructed  as  to  form  a  shunt  circuit  with  the  j)atient's  circuit.  In 
the  former  case  the  current  is  modified  by  a  rheostat  capable  of  increasing 
and  decreasing  the  resistances,  while  in  the  latter  the  device  is  such  as  to 
admit  a  greater  or  less  flow  of  current  into  the  shunt  circuit.  The  princi- 
pal difference  between  these  methods  of  controlling  the  dynamo  current 
is  that  in  the  former  the  electromotive  force  remains  the  same  regardless 
of  the  amount  of  current  the  patient  is  receiving,  while  in  the  latter  this 
electromotive  force  varies  with  the  current  received. 

These  instruments  can  be  so  controlled  that  the  graduation  will  be  exact. 

Milliamperemeters. — Exact  work  in  electrotherapeutics  cannot  be 
accomplished  when  using  the  direct  current  without  the  means  of  accu- 
rately measuring  that  current. 

The  milliamperemeter  offers  the  means  of  measuring  ~  the  strength 
of  the  carreut  being  used,  and  this  is  of  first  importance  in  cataphoric 
work,  as  it  enables  the  operator  to  measure  the  i-esistance  of  the  tissues  in- 
volved in  the  circuit,  and  offers  a  sure  means  of  detecting  any  leakage  of 
the  current,  which  is  also  important,  for  if  it  is  not  discovered,  it  prolongs 
the  time  necessary  to  produce  the  desired  result  or  cause  it  to  end  in  com- 
plete failure.  Currents  used  upon  the  body  for  therapeutic  purposes  never 
exceed  one-half  an  ampere,  or  five  hundred  milliamperes,  and  for  nearly 
all  cataphoric  work  much  less  than  this,  from  five  to  twenty  milliamperes 
being  about  the  limits  of  the  customary  range. 


CATAPHOEESIS. 


207 


Fig.  317. 


Weston's  dead-beat  milliam- 
peremeter. 


Five  milliamperes  of  current  for  dental  cataplioresis  is  often  more  than 
can  be  used.  A  current  strength  of  from  two-tenths  to  two  milliamperes 
is  usually  all  that  can  be  borne  without  pro- 
ducing pain. 

There  are  two  forms  of  milliamperemeters  in 
use  by  physicians  and  dentists.  In  one  the  needle 
is  magnetic  and  arranged  to  freely  turn  upon  a 
pivot,  and  is  easily  influenced  by  outside  magnetic 
forces.  The  needle  is  deflected  away  from  the 
earth's  magnetic  meridian  by  the  electric  current 
which  traverses  a  coil  of  wire  which  is  parallel 
with  the  magnet  before  the  current  passes.  In 
the  other  the  construction  is  such  that  the  indi- 
cator comes  instantly  at  rest,  and  has  no  period 
of  oscillation  before  the  measurement  can  be  read, 
— in  other  words,  it  is  what  is  termed  "dead-beat."  (Fig.  317  shows  such 
an  instrument.)  These  instruments  are  made  with  a  double  scale,  one  for 
strong  and  the  other  for  weak  currents,  the  scale  for  the  weaker  current 
being  divided  into  twentieths  of  a  milliampere. 

Conducting  Cords  and  Tips. — The  conducting  cords  are  made  of 
bunches  of  fine  copper  wire  covered  with  cotton  or  silk,  and  should  be 
pliable  as  well  as  strong  and  durable.  If  the  cords  are  not  made  of  good 
material,  the  strands  or  threads  are  liable  to  be  broken  with  use,  and  the 
current  thus  be  rendered  fitful  or  interrupted  by  such  defects. 

The  tips  or  terminals  are  metal  devices  placed  at  either  end  of  the  con- 
ducting cords  for  attaching  them  to  the  binding  posts  and  the  electrodes. 

Electrodes. — These  of  necessity  are  made  of  various  materials  and 
of  many  sizes  and  shapes  to  meet  the  demands  of  special  forms  of  treat- 
ment. The  practical  medical  and  surgical  electrotherapeutist  will  need 
an  entirely  different  line  of  electrodes  from  those  required  by  the  dental 
surgeon.  Fig.  318  shows  a  selection  of  electrodes  employed  by  the  dental 
surgeon. 


ELECTEOCOOAINE   ANAESTHESIA. 

As  a  means  of  obtunding  hypersensitive  dentin,  ansesthetizing  the  den- 
tal pulp,  and  producing  local  anaesthesia  for  tooth  extraction,  the  cata- 
phoric or  electrolytic  action  of  the  direct  electric  current  in  carrying 
cocaine  into  the  dental  tissues  and  thus  paralyzing  the  function  of  sensa- 
tion bids  fair  to  become  the  most  important  means  which  has  ever  been 
placed  in  the  hands  of  the  dentist  for  relieving  the  pain  of  dental  opera- 
tions. Many  successes  and  also  many  failures  have  been  reported  in  the^ 
use  of  cataphoresis.  The  failures  have  been  the  result,  no  doubt,  of  those 
conditions  which  always  surround  any  new  method  of  treatment,  espe- 
cially if  it  introduces  remedies  or  forces  the  action  of  which  are  more  or 
less  imperfectly  understood,  as  was  the  case  with  nitrous  oxide,  ether,  and 
chloroform.  But  in  time  these  difficulties  will  be  eliminated  by  research 
and  experimentation,  and  the  methods  of  treatment  so  perfected  that  fail- 
ures will  become  either  a  matter  of  an  individual  idiosyncrasy  of  th& 


208 


OPEEATIVE    DENTISTRY. 


patient  or  of  a  lack  of  ability  upon  the  part  of  the  operator  to  manipu- 
late the  apparatus. 

The  solutions  of  cocaine  which  are  used  in  cataphoresis  vary  in  strength 
from  ten  to  forty  per  cent.     These  solutions  may  be  made  from  either  the 


Fig.  318. 


'^      / 


Cataphoric  electrodes. 


hydrochlorate  or  the  citrate,  dissolved  in  distilled  water,  glycerol,  guaiacol, 
or  guaiacol  and  ether.  Morton  recommends  making  fresh  solutions  for 
each  case,  because  of  the  fact  that  cocaine  solutions  deteriorate  and  lose 
their  anaesthetic  property  in  a  large  measure  in  a  few  days. 


CATAPHORESIS. 


209 


Fig.  319. 


Apparatus. — The  apparatus  necessary  for  j^roducing  electrococaine 
anaesthesia  are  a  suitable  primary  galvanic  battery  ;  preferably  a  dry-cell 
chloride  of  silver,  or  a  dry-cell  Leclanche  battery,  having  an  electro- 
motive force  of  from  ten  to  thirty-five  volts ;  a  reliable  rheostat  or  con- 
troller so  arranged  that  the  current 
may  be  increased  or  diminished  by 
slow  gradations  at  the  will  of  the  oper- 
ator ;  a  milliamperemeter  graduated 
to  register  the  twentieth  part  of  a 
milliampere ;  conducting  cords  and 
electrodes. 

The  secondary  or  storage  battery 
is  sometimes  employed  for  producing 
cataphoresis.  When  this  form  of  bat- 
tery is  used  the  plates  should  be 
small, — three  by  three  inches.  The 
potential  of  a  cell  of  this  size  will 
be  about  two  volts,  and  the  normal 
strength  of  current  at  eight  hours' 
discharge  is  five- eighths  of  an  ampere. 

The  Edison  one-hundred-and-ten- 
volt  street  current  may  also  be  em- 
ployed by  suitably  reducing  the 
strength  of  the  current.  The  objec- 
tions which  have  been  raised  to  the 
use  of  this   current  are  the   dangers 

from  severe  shock,  if  by  chance  the  apparatus  should  be  defective,  or 
lightning  should  strike  the  supply  wire,  or  it  should  become  crossed  with 
one  carrying  a  current  of  much  higher  potential.  These  dangers  may  be 
guarded  against  by  placing  the  mains  underground,  as  is  now  being  done 
in  all  of  our  large  cities,  and  by  inserting  a  suitable /tm&?e  wire  connection 
in  the  apparatus  that  will  not  carry  a  current  of  greater  strength  than 
one-half  an  ampere. 

In  the  arrangement  of  the  apparatus  for  cataphoric  work,  the  battery, 
or  other  source  of  current,  the  rheostat,  the  milliamperemeter  and  the 
patient  are  in  series  (Fig.  320).  The  direction  of  the  current  being  from 
the  battery  to  the  rheostat,  from  the  rheostat  to  the  milliamperemeter, 
from  the  milliamperemeter  to  the  patient,  from  the  patient  back  through 
the  rheostat  to  the  battery,  thus  making  the  circuit  complete. 

The  resistance  encountered  in  the  flow  of  the  current  are  found  in  the 
conducting  wires,  the  rheostat,  and  the  tissues  of  the  patient ;  the  skin 
and  the  dentin  being  more  highly  resistant  than  the  other  tissues  through 
which  the  current  must  pass  in  treating  hypersensitive  dentin.  The  result 
of  resistance  to  the  flow  of  an  electric  current  is  the  x^i'oduction  of  heat, 
the  amount  of  heat  produced  being  governed  by  the  degree  of  the  resist- 
tance,  and  the  size  and  character  of  the  conductor. 

Dentin  is  exceedingly  resistant  to  the  passage  of  a  current  of  electricity, 
consequently  heat  is  liable  to  be  produced  if  the  pressure  of  the  current  is 

14 


Cataphoric  outfit  Avithout  miliiamperemeter. 


210 


OPERATIVE    DENTISTRY. 


too  great,  aud  pain  would  be  the  result.  The  teeth  are  very  sensitive  to 
an  electric  current,  and  respond  vigorously  to  any  sudden  change  in  the 
pressure  or  strength  of  current- flow  or  amperage.  There  is,  however,  a 
considerable  variation  between  individuals  and  between  different  teeth  in 
the  same  individual  as  to  the  amount  of  current  that  can  be  used  upon 
the  teeth  without  causing  pain.      With  some   individuals  the  limit  is 


Fig.  320. 


^ 


"/ 

TttXve  M.5 

/ 

\ 

n 

CCrcwvt 

/ 

\ 

1^ 

-►vrvif" 

r' 

^>nrvrf^ 

'^T^tT 

r 

i 

J)»y 

B,, 

T,, 

J,y 

Dry 

CclL 

c.vi 

CcW 

CtVU 

avL 

reached  with  a  pressure  of  four  or  five  volts  and  one- tenth  of  a  milli- 
ampere  of  current.  Under  such  circumstances  it  becomes  necessary  to 
increase  the  pressure  very  slowly  until  the  cocaine  paralyzes  somewhat  the 
function  of  sensation  in  the  dentin.  While  in  others  the  pain  limit  may 
nnt,  be  attained  until  the  pressure  reaches  fifteen  to  twenty  volts,  with  an 


CATAPHORESIS.  211 

amperage  of  from  three-tenths  to  four-teaths  of  a  milliampere.  The 
anterior  teeth  seem  to  be  the  most  susceptible  to  the  galvanic  current. 
Teeth  having  acutely  inflamed  pulps  are  also  exceedingly  sensitive  to  the 
current,  even  at  very  low  initial  voltage. 

Another  factor  in  this  connection  which  must  be  taken  into  considera- 
tion is  the  nervous  irritability  of  the  patient,  which  when  highly  exalted 
may  render  them  peculiarly  susceptible  to  the  irritation  of  an  electric 
current. 

Resistance  of  Tissues. — According  to  Dr.  W.  A.  Price,*  the  average 
resistance  of  a  patient  is  about  twenty-five  thousand  ohms  from  the  cavity 
to  the  hand  holding  the  negative  electrode  or  cathode.  This  was  com- 
puted from  twenty-five  cases,  varying  all  the  way  from  ten  thousand  to 
seventy-eight  thousand  ohms  and  higher.  The  difference  of  resistance  from 
the  hand  to  the  tooth  and  from  the  cheek  to  the  tooth  he  found  to  be  from 
three  thousand  to  five  thousand  ohms.  In  one  case,  in  which  the  resistance 
was  measured  with  the  cavity  barely  moist,  it  gave  a  resistance  of  forty- 
seven  thousand  seven  hundred  ohms.  On  applying  a  forty  per  cent,  solu- 
tion of  cocaine  in  water  to  the  cavity,  the  resistance  was  reduced  to 
twenty-eight  thousand  five  hundred  ohms,  and  upon  transferring  the 
cathode  to  the  cheek  it  was  further  reduced  to  twenty-three  thousand  eight 
hundred  ohms. 

The  greater  portion  of  the  resistance  is,  therefore,  according  to  the 
above  statements,  in  the  tooth. 

Dr.  Price  further  states  that  the  average  resistance  from  the  hand  to 
the  tongue  with  small  electrodes  is  about  nine  thousand  ohms,  varying 
from  seven  thousand  to  twelve  thousand  ;  and  from  the  cheek  to  the  tongue 
about  five  thousand  ohms,  varying  from  three  thousand  to  seven  thousand. 
This  places  the  greater  part  of  the  resistance  of  the  tissues  of  the  patient 
in  the  dentin  of  the  tooth,  which  varies  all  the  way  from  ten  thousand  to 
seventy  thousand  ohms,  with  an  average  of  about  twenty  thousand. 

Sections  of  dentin  in  the  fresh  state  tested  out  of  the  mouth  in  an 
almost  dry  condition,  and  also  when  saturated  with  various  solutions,  gave 
a  wide  range  of  resistance.  As  an  illustration,  a  longitudinal  section  of 
fresh  dentin,  five  millimetres  thick  and  almost  dry  upon  the  surface,  had 
a  resistance  of  thirty  thousand  ohms  ;  after  drying  and  then  saturating  with 
a  forty  per  cent,  solution  of  cocaine  the  resistance  was  reduced  to  four 
thousand  five  hundred  ohms,  and  after  drying  and  saturating  with  a  solu- 
tion of  sodium  chloride  the  resistance  was  reduced  to  three  thousand  and 
seventy  ohms. 

From  the  statement  of  the  foregoing  facts,  and  the  principles  involved 
in  applying  the  galvanic  current  to  the  human  body  for  its  cataphoric 
effects  upon  hypersensitive  dentin,  it  becomes  patent  that  the  greatest  care 
must  be  exercised  in  the  selection  of  the  initial  degree  of  voltage ;  in 
employing  a  relatively  low  amperage  and  carefully  measuring  the  strength 
of  current  used  ;  in  so  controlling  the  current  that  it  may  be  increased  or 
diminished  by  imperceptible  gradations  ;   in  avoiding  a  breaking  of  the 

*  Dental  Cosmos,  vol.  xxxix.  p.  90. 


212  OPERATIVE    DENTISTRY. 

current,  or  too  rapidly  advancing  the  strength  of  the  current,  and  in  main  ^ 
taining  a  moist  condition  of  the  cavity  during  the  flow  of  the  current. 

METHOD   OF   ADMINISTRATION. 

The  first  step  in  the  application  of  the  galvanic  current  for  electro- 
cocaine  ansesthesia  by  hypersensitive  dentin  is  the  isolation  of  the  tooth 
to  be  operated  upon  by  means  of  a  rubber  dam,  which  must  be  securely 
ligated  at  the  cervix  to  prevent  leakage  of  moisture  or  of  the  current. 
As  an  added  precaution  against  leakage,  the  cervix  of  the  tooth  should  be 
coated  with  some  quick-drying  varnish.  If  metallic  fillings  are  present 
in  the  tooth  to  be  operated  upon,  or  in  the  ai^proximal  surfaces  of  the 
adjoining  teeth  included  in  the  rubber  dam,  these  should  likewise  be 
covered  with  varnish,  or  an  extra  rubber  dam  may  be  placed  on  the  tooth 
to  be  treated  for  the  purpose  of  insulating  them,  or  otherwise  the  current 
would  be  dissipated  from  the  cavity  by  being  switched  off  or  shunted  by 
these  conductors. 

The  cavity  of  decay  should  be  carefully  irrigated  with  tepid  water 
before  adjusting  the  rubber  dam,  with  the  object  of  removing  all  the  food 
debris  and  detached  portions  of  disorganized  tissue. 

It  is  not  necessary  to  attempt  to  remove  the  carious  dentin  before  the 
application  of  the  cocaine,  and  the  surface  of  the  cavity  need  not  be  more 
than  partially  dehydrated. 

A  pledget  of  cotton  large  enough  to  loosely  fill  the  cavity  is  then  satu- 
rated with  the  cocaine  solution  and  placed  in  the  cavity.  The  cathode  is 
next  placed  in  the  hand  of  the  patient  or  applied  to  the  cheek,  neck,  or 
other  suitable  location.  If  the  cathodal  electrode  is  covered  with  sponge, 
this  should  be  moistened  with  water,  or,  better,  with  a  solution  of  sodium 
chloride.  The  anode  is  now  applied  to  the  cotton  in  the  cavity  and 
the  current  turned  on,  care  being  taken  to  start  with  the  lowest  voltage 
and  weakest  amperage.  To  obtain  the  best  results  from  the  cataphoric 
effect  of  the  current  the  point  of  the  anode  (which  should  be  made  of 
platinum)  should  have  a  diameter  as  nearly  the  size  of  the  cavity  as  possi- 
ble, but  as  this  would  necessitate  purchasing  a  very  large  number  and 
variety  of  platinum  anodal  tips,  the  writer  uses  instead  platinum  disks 
cut  from  ISTo.  30  gauge  plate,  and  perforated  with  numerous  holes  for  the 
ready  passage  of  a  reserve  supply  of  the  cocaine  solution.  These  disks 
may  be  kept  on  hand  in  a  variety  of  sizes  and  shapes  at  a  very  trifling 
expense. 

One  of  these  disks  is  placed  over  the  cotton,  care  being  taken  that  it 
does  not  touch  the  dentin,  and  the  anode  applied  to  this.  As  a  result  of 
using  electrodes  with  points  whose  cross- section  nearly  equals  the  diameter 
of  the  cavity,  greater  diffusion  of  current  is  secured  than  is  possible  with 
small  points,  unless  metal  disks  are  used  in  conjunction  with  them,  as  just 
suggested. 

Many  operators  have  complained  of  their  inability  to  secure  complete 
anaesthesia  over  the  whole  surface  of  the  cavity  when  employing  catapho- 
resis,  except  by  prolonged  application.  This  is  explained  upon  the  sup- 
position that  the  surface  contact  area  of  the  anode  was  too  small  to  cover 


CATAPHORESIS.  213 

the  area  of  dentin  upon  which  it  was  desired  to  produce  anaesthesia.  It 
is  a  law  of  electricity  that  the  current  travels  by  the  path  of  the  least 
resistance.  This  in  the  vital  tooth  ls  by  the  organic  matter  in  the  tubuli 
and  the  contents  of  the  pulp-chamber.  Primary  ansesthesia  will  therefore 
occur  only  over  the  radius  covered  by  the  positive  pole,  because  the  current 
passes  directly  from  the  anode  to  those  tubuli  which  are  in  the  direct  path 
of  the  current.  Secondary  anaesthesia  of  the  dentin  may  be  secured  by 
producing  anaesthesia  of  the  pulp,  as  no  doubt  occurred  in  some  of  those 
cases  reported  in  which  the  anaesthetic  effect  of  the  treatment  was  secured 
only  after  a  very  long  application  of  the  current  through  a  small  pointed 
anode,  while  in  others  it  was  due  to  leakage  of  current  or  great  density  of 
the  tooth. 

The  anode  should  be  constructed  with  a  reservoir  for  holding  a  reserve 
supply  of  the  solution,  like  Morton's  tubular  cataphoric  applicator,  or, 
better  still,  the  syringe  electrode  of  the  S.  S.  White  Company  (Fig.  321). 

Fig.  321. 


Syringe  electrode. 

Teeth  which  are  termed  soft,  or  imperfectly  calcified,  especially  chil- 
dren's teeth,  respond  more  readily  to  electrococaine  anaesthesia  than  do 
that  class  of  teeth  which  are  termed  dense,  or  highly  calcified,  as  the  greater 
amount  of  organic  matter  in  the  former  renders  them  better  conductors 
of  the  electric  current. 

When  the  current  is  first  turned  on  to  the  tooth  a  slight,  uneasy  sensa- 
tion is  experienced,  but  this  immediately  passes  away,  and  the  strength 
of  the  current  may  then  be  gradually  increased  a  fraction  of  a  milliampere 
at  a  time,  or  until  the  j^atient  again  becomes  conscious  of  the  current- 
pressure,  but  under  no  circumstances  should  it  be  advanced  to  such  a  de- 
gree as  to  be  painful.  The  best  results  are  obtained  with  low  amperage 
— from  one  to  three  milliamperes  as  the  maximum — and  increasing  the  cur- 
rent very  slowly.  As  anaesthesia  advances  the  strength  of  the  current  may 
be  more  rapidly  increased,  but  a  current  strength  above  five  milliamperes 
is  rarely  required,  and,  finally,  when  this  can  be  done  without  producing 
unpleasant  sensations,  anaesthesia  may  be  considered  as  complete,  the 
switch  slowly  carried  back  to  the  zero  point,  and  the  operation  of  cavity 
preparation  commenced. 

With  a  current  above  five  milliamperes  there  is  danger  of  decomposing 
the  chemic  structure  of  the  cocaine,  or  of  producing  coagulation  of  the 
albuminoid  elements  of  the  dentin  by  electrolysis. 

The  period  of  application  of  the  current  may  be  stated  to  be  from  eight 


214  OPERATIVE    DENTISTRY. 

to  fifteen  minutes  in  ordinary  cases,  but  in  teeth  wliicli  are  very  dense  a 
much  longer  period  is  sometimes  required. 

The  milliamperemeter  should  be  carefully  watched  during  the  whole 
period  of  administration.  Any  rapid  movement  of  the  indicator,  or  a 
registration  of  a  greater  amperage  than  the  dentin  would  admit,  even  at 
a  higher  voltage  than  that  being  used  at  the  time,  would  be  a  sure  sign 
that  the  current  had  found  a  path  offering  less  resistance  than  the  dentin, 
and  if  this  is  not  corrected  the  administration  will  prove  a  failure. 

It  is  wise  to  always  test  the  polarity  of  the  terminals  before  applying 
the  current.  This  may  be  done  by  bringing  the  ends  of  the  terminals 
together,  when  the  switch  of  the  rheostat  is  on  the  first  or  second  point, 
or  they  may  be  tested  with  wet  litmus-paj)er,  or  paper  moistened  with 
solution  of  potassium  iodide,  when  the  j)Ositive  pole  will  give  the  charac- 
teristic reaction. 

It  has  already  been  stated  that  the  positive  pole  produces  coagulation 
of  the  albuminoid  substances  contained  in  the  tissues,  and  this  may  result 
in  the  dentin  if  too  strong  a  current  is  used.  This  no  doubt  has  been 
another  source  of  failure  in  electrococaine  anaesthesia.  The  use  of  coagu- 
lating remedies  like  carbolic  acid  should  never  be  allowed  in  a  cavity 
when  catai)horesis  is  to  be  employed,  as  coagulated  albumin  is  not  a  good 
conductor  of  electricity,  and  hence  the  diffusion  of  the  cocaine  by  the 
current  would  be  greatly  retarded. 

GENERAL   ANESTHESIA. 

The  employment  of  general  ansBSthetics  sometimes  becomes  necessary 
in  the  treatment  of  hypersensitive  dentin,  but  they  should  be  resorted  to 
only  in  extreme  cases,  when  all  local  means  have  failed,  or  when  for  some 
reason  they  cannot  be  employed. 

The  general  anaesthetics  which  have  been  used  for  this  purpose  are 
nitrous  oxide,  sulphuric  ether,  and  chloroform.  In  the  employment  of  these 
remedies  for  obtunding  the  hypersensitiveness  of  the  dentin,  the  confidence 
and  intelligent  co-operation  of  the  patient  is  a  sine  qua  non,  for  the  reason 
that  a  profound  anaesthesia,  or  even  loss  of  consciousness,  is  not  necessary 
or  even  desirable  if  the  best  results  are  to  be  obtained  from  their  employ- 
ment. During  t\iQ  first  stage  of  anaesthesia,  or  just  before  the  second,  or 
stage  of  excitement,  appears,  sensation  in  the  peripheral  extremities  of  the 
nerves  is  greatly  diminished  or  entirely  obliterated,  so  that  it  becomes 
possible  to  make  slight  incisions  in  the  skin  or  mucous  membrane,  or  cut 
the  most  sensitive  dentin  without  the  slightest  sensation  of  pain. 

During  the  first  stage  of  anaesthesia  the  patient  is  drowsy  and  the  mus- 
cles are  relaxed,  but  conscious  cerebration  is  not  impaired.  This  is  an  im- 
portant consideration,  for  upon  this  fact  rests  the  co-operation  of  the  patient, 
and  this  is  absolutely  necessary  if  the  operation  is  to  be  successfully  per- 
formed. If  the  administration  of  the  drug  is  continued  to  the  develop- 
ment of  the  stage  of  excitement,  the  patient  becomes  unmanageable,  and 
all  delicate  operative  procedure  is  at  an  end  ;  while  if  profound  anaesthesia 
is  induced,  the  insensible  condition  of  the  patient  renders  that  co-operation 
which  is  so  desirable  to  the  performance  of  such  operations  entirely  out 


CATAPHOKESIS. 


215 


of  the  question.  Furtliermore,  the  upright  position  of  the  patient  is 
necessary  to  the  performance  of  these  operations,  which  adds  greatly  to  the 
dangers  surrounding  general  anaesthesia,  especially  when  chloroform  is 
used. 

If,  upon  the  other  hand,  it  becomes  necessary  to  remove  a  vital  pulp, 
nothing  short  of  a  profound  state  of  anaesthesia  will  suffice  for  a  painless 
operation. 

Nitrous  Oxide. — The  use  of  nitrous  oxide  as  a  means  of  producing 
partial  ansesthesia  for  the  relief  of  pain  in  operating  upon  hypersensitive 
dentin  has  often  been  advocated  and  successfully  employed. 

In  the  use  of  this  agent  the  assistant  should  stand  by  the  side  of  the 
chair  ready  to  turn  the  gas  on  or  off  as  the  needs  of  the  case  may  require. 
It  should  then  be  explained  to  the  patient  that  five  or  six  deep  inspira- 
tions will  usually  be  sufficient  to  render  the  cutting  of  the  dentin  an 
entirely  painless  operation,  but  that  this  insensibility  to  pain  will  last  only 
for  two  or  three  minutes,  consequently  it  becomes  necessary  to  operate 
very  rapidly,  and  to  this  end  the  assistance  and  co-operation  of  the  patient 
is  earnestly  solicited.  Assurance  should  also  be  given  that  upon  the 
slightest  indication  of  a  return  of  painful  sensations  the  gas  shall  be 
again  administered  and  this  process  repeated  until  the  cavity  has  been 
prepared.  AVith  these  explanations  and  assurances  the  confidence  of  the 
most  timid  patient  will  be  secured  and  intelligent  co-operation  obtained. 

The  inhaler  (Fig.  322)  should  then  be  placed  in  the  hands  of  the  patient 
and  instruction  given  in  the  method  of  applying  it  and  of  breathing.  The 
gas  is  now  turned  on,  and  after  five  or 
six  full  inspirations  have  been  taken, 
the  inhaler  may  be  removed  and  the 
sensitiveness  of  the  dentin  tested, 
and  if  it  has  disappeared,  the  exca- 
vation of  the  cavity  may  be  proceded 
with,  but  if  not,  then  three  or  four 
inspirations  more  may  be  taken, 
when  the  sensitivity  of  the  dentin 
will  be  found  to  have  been  entirely 
overcome.  As  soon  as  the  anaesthetic 
effect  begins  to  pass  off  the  inhala- 
tions should  be  renewed. 

Sulphuric  ether  is  perhaps  the  most 
reliable  general  anaesthetic  that  can 
be  employed  for  this  purpose,  as  the 
obtunding  effect  upon  peripheral 
sensation  is  more  lasting  than  nitrous 
oxide,  and  far  less  dangerous  than 
chloroform  to  the  life  of  the  patient. 

In  administering  ether  care  should 
be  exercised  in  the  selection  of  an  inhaler  to  obtain  one  that  will  permit 
an  abundant  admixture  of  atmospheric  air  with  the  ether  vapor,  as  by 
this  precaution  the  irritation  to  the  air-passages  which  is  so  common  in 


Fig.  322. 


Flexible  face-piece  for  inhalers. 


216 


OPERATIVE    DENTISTRY. 


Fig.  32.3. 


Allis's  ether  inhaler, 
rubber  covered. 


the  early  part  of  ether  anaesthesia  is  entirely  obviated.  The  Allis  inhaler 
(Fig.  323)  is  constructed  with  this  object  in  view,  and  is  the  best  invention 
of  its  kind  that  is  manufactured. 

The  time  required  to  produce  peripheral  anaesthe- 
sia is  about  two  minutes,  and  it  lasts  fronl  two  to  five 
minutes. 

When  ether  is  to  be  employed  for  its  anaesthetic 
effect,  the  patient  should  be  cautioned  against  eating 
just  before  the  operation,  as  under  such  circumstances 
nausea  and  vomiting  might  occur.  It  is  safest  to 
take  only  a  light  meal  three  or  four  hours  before  the 
operation  and  no  stimulants.  With  these  jjrecau- 
tions  there  need  not  be  the  slightest  fear  of  any 
unpleasant  symptoms  attending  or  following  the 
employment  of  ether  for  this  purpose. 

Chloroform  has  been  employed  by  some  operators, 
while  others  have  used  the  A.  C.  E.  mixture, — alcohol 
one  part,  chloroform  two  parts,  ether  three  parts. 

Chloroform  and  the  A.  C.  E.  mixture  are  not  safe  remedies  to  use 
for  producing  anaesthesia  when  the  patient  must  be  seated  in  an  upright 
position,  on  account  of  the  depressing  effect  of  chloroform  upon  the  action 
of  the  heart.  Chloroform  and  its  combinations  are  therefore  contraindi- 
cated  in  all  operations  requiring  the  erect  position  as  an  essential  feature 
of  the  procedure. 

Bon  will  Method  of  Rapid  Breathing. — The  late  Dr.  Bonwill  advo- 
cated several  years  ago  a  system  of  rapid  breathing  as  a  means  of  pro- 
ducing peripheral  anaesthesia.  The  system  consists  of  making  very 
rapid  and  full  inspirations  and  expirations — as  though  one  were  running 
— and  keeping  this  up  until  the  head  becomes  dizzy,  when  it  is  found  that 
peripheral  sensation  has  been  greatly  obtunded,  and  in  some  cases  as  com- 
pletely obliterated  for  a  brief  period  as  though  some  anaesthetic  drug  had 
been  administered.  The  writer  has  occasionally  employed  this  method 
with  very  great  satisfaction  in  the  treatment  of  hypersensitive  dentin,  and 
in  a  few  instances  has  also  extracted  teeth  which  the  patients  have  de- 
clared was  done  without  producing  the  slightest  painful  sensations. 


CHAPTER    XV. 


THE    CLASSIFICATION   OF   CAVITIES. 


Carious  cavities  in  the  human  teeth  are  usually  divided  into  two  gen- 
eral classes, — viz.,  simple  and  compound.  These  have  been  again  divided 
into  three  general  classes, — viz.,  1,  simple  cavities  upon  exposed  surfaces ;  2, 
simple  approximal  cavities;  3,  compound  cavities. 

The  Jirst  division  includes  all  of  those  cavities  which  are  found  upon  the 
morsal,  buccal,  labial,  and  lingual  surfaces  of  the  teeth,  which  afford  easy 
and  direct  approach  to  all  parts  of  the  cavity,  and  which  are  bounded  by 
a  continuous  and  unbroken  wall  of  regular  or  irregular  outline. 

The  second  division  comprises  all  of  those  cavities  which  are  located 
ui3on  the  approximal  surfaces  of  the  teeth,  and  are  likewise  bounded  by  a 
continuous  and  unbroken  wall,  but  which  do  not,  on  account  of  their 
location,  give  ready  and  direct  approach  to  all  parts  of  the  cavity,  except, 
first,  by  separating  the  teeth,  and  secondly,  by  using  instruments  for  their 
preparation  which  have  been  curved  or  bent  at  suitable  angles. 

The  third  division  is  made  up  of  all  those  cavities  which  are  produced 
by  a  union  of  two  or  more  cavities  of  the  previous  divisions,  no  matter 
whether  they  have  been  united  by  the  extension  of  the  process  of  caries 
or  by  surgical  means. 

Weeks,  in  his  '^  Manual  of  Operative  Technics,"  offers  the  following 
classification  of  cavities  : 

A. — Cavities  arising  from  structural  imper- 
■   fections  in  pits  and  fissures. 

B. — Cavities  on  labial,  buccal,  or  lingual 
surfaces,  caused  by  contact  with 
secretions  from  diseased  tissues,  or 
the  products  of  fermentation. 


Class  1. 


All   cavities  on  any  surface 
other  than  proximate. 


(All  cavities  on  the  proximate 
surfaces  of  incisors  and 
cuspids. 


A. — Cavities  which  do    not    involve    the 
mesial  or  distal  angle. 

B. — Cavities  which  involve  the  restoration 
of  the  mesial  or  distal  angle. 


Class  3. 


All  cavities  on  the  proximate 
surfaces  of  bicuspids  and  ■ 
molars. 


f  A. — Cavities  which  include  the  marginal 
ridge,  but  do  not  involve  any  sulci 
or  grooves  upon  the  occlusal  surface. 

B. — Cavities  which  involve  not  only  the 
marginal  ridge,  but  also  the  sulci 
or  grooves  upon  the  occlusal  surface. 


For  the  purposes  of  more  accurately  locating  and  describing  each  indi- 
vidual cavity,  the  following  admirable  division  and  classification  has  been 
taken  from  the  "American  Text-Book  of  Operative  Dentistry,"  and  slight 
changes  made  in  it  to  give  it  a  more  comprehensive  application.     This 

217 


218 


OPERATIVE    DENTISTRY. 


classification  is  arranged  progressively  from  the  simplest  form,  A,  to  the 
most  complex,  W. 

The  writer,  however,  takes  the  liberty  of  changing  the  terms  occlusal 
and  incisal,  to  morsal,  as  the  latter  term  is  equally  applicable  to  both,  and, 
as  a  multijDlication  of  terms  is  to  be  avoided,  there  can  be  no  valid  objec- 
tion to  the  change. 

I.     Simple  Cavities  upon  Exposed  Surfaces. 
Incisors  and  Cuspids.  Bicuspids  and  Molars. 

A.  Labial  D.  Morsal. 

B.  Lingual.  E.  Buccal. 

C.  Morsal.  F.  Lingual. 

II.     Simple  Appeoximal  Cavities. 


Incisors  and  Cuspids. 

G.  Mesial. 

H.  Distal. 

III.     Compound 
Incisors  and  Cuspids. 
K.  Mesio-labial. 
L.  Disto-labial. 
M.  Mesio-lingual. 
N.  Disto-lingual. 
O.  Mesio-morsal. 
P.  Disto-morsal. 
Q.  Mesio-disto-morsal. 


Bicuspids  and  Molars. 
I.  Mesial. 
J.  Distal. 
Cavities. 

Bicuspids  and  Molars. 
K.  Mesio-morsal. 
S.  Disto-morsal. 
T.  Morso-buccal. 
U.  Morso-lingual. 
V.  Mesio-disto-morsal. 
W.  Bucco-linguo-morsal. 


Adopting  this  arrangement  and  classification  as  the  best,  the  writer  will 
adhere  to  it  in  all  future  descriptions  of  the  location  of  carious  cavities  and 
of  fillings. 

I.    SIMPLE   CAVITIES   UPON   EXPOSED   SURFACES. 

Incisors  and  Cuspids. 

A  Class. — Cavities  upon  the  lahial  surface  of  the  incisors  and  cuspids  are 
usually  found  in  two  locations, — viz.,  at  the  cervix  and  near  the  morsal  edge. 

Cavities  at  the  cervix  in  the  early  stage  of  the  carious  process  are 
generally  in  full  view,  and  may  consist  of  a  softened  condition  of  the 
enamel  without  visible  loss  of  structure,  or  they  may  present  any  of  the 
characteristics  of  the  more  advanced  stages  of  the  carious  process.  Fig. 
324,  A,  A,  shows  the  form  and  location  of  this  class  of  cavities. 


Fig.  324. 


Fig.  325. 


Fig.  326 


The  preparation  of  those  cavities  which  occur  at  the  cervix  offer  no 
serious  difficulties,  unless  they  extend  beneath  the  gum.  Under  such  cir- 
cumstances it  becomes  necessary,  in  order  to  gain  a  good  view  of  the 


THE    CLASSIFICATION    OF    CAVITIES.  219 

cavity  and  to  properly  prepare  the  cervical  margin,  to  evert  the  overhang- 
ing gum.  In  the  simpler  cases  this  may  be  accomplished  by  pressing  the 
gum  away  with  a  suitable  instrument  held  in  the  left  hand  during  the 
preparation  of  the  cavity,  care  being  exercised  not  to  wound  the  gum,  as 
the  hemorrhage  would  obstruct  the  view.  In  the  more  complicated  cases, 
where  the  edge  of  the  gum  has  become  inverted,  it  is  necessary  either  to 
excise  the  inverted  gum  tissues  or  to  evert  them  by  packing  the  cavity 
over-full  with  gutta-percha  and  allowing  it  to  remain  for  a  few  days.  This 
procedure  gives  a  clear  field  for  the  preparation  of  the  cavity  and  the 
subsequent  operation  of  filling.  The  adjustment  of  the  rubber  dam  is 
sometimes  a  difficult  procedure  in  these  cases,  but  it  can  usually  be  ac- 
complished by  exercising  a  due  amount  of  patience.  Absolute  dryness  of 
the  cavity  is  imperatively  demanded  in  a  proper  preparation,  as  well  as 
for  the  subsequent  operation  of  filling.  Spoon  excavators  and  round  burs 
will  be  found  to  be  the  most  useful  instruments  in  the  preparation  of  these 
cavities.  Eetention  may  be  obtained  by  slight  uuder-cuts  at  the  bottom 
of  the  cavity,  at  the  cervical  and  morsal  margins,  and  following  its  outline 
from  one  extremity  to  the  other.  Too  much  care  cannot  be  expended  in 
the  preparation  of  the  margins  and  terminal  points  of  these  cavities.  They 
should  be  nicely  bevelled,  as  shown  in  Fig.  325,  and  finished  as  smoothly 
as  possible,  so  that  the  margin  of  the  filling  when  finished  will  present  a 
perfect  outline. 

Cavities  which  occur  upon  the  labial  surface  near  the  morsal  edge  are 
the  result  of  developmental  defects  in  the  enamel  in  the  form  of  pits  and 
grooves,  which  cross  the  surface  in  nearly  a  straight  line  or  surround  or 
girdle  the  entire  tooth  at  an  equal  distance  from  the  morsal  edge.  This 
condition  is  shown  in  Fig.  326,  A. 

These  imperfections  when  quite  shallow  may  be  removed  by  corundum 
wheels  and  the  surface  polished.  If,  however,  they  are  deep,  it  is  better 
in  the  case  of  small  pits  to  treat  each  one  as  a  separate  cavity,  as  illus- 
trated in  Fig.  326,  B,  but  when  they  are  large,  leaving  but  little  tooth  sub- 
stance between  them,  or  in  the  case  of  deep  grooves,  it  is  better  to  convert 
them  into  a  single  cavity  and  fill  it  with  gold,  or  set  a  porcelain  inlay  ; 
but  when  the  groove  girdles  the  tooth  and  is  deep,  the  better  plan  for  the 
sake  of  the  cosmetic  eifect  would  be  to  cut  off  the  tip  and  replace  it  with 
porcelain. 

B  Class. — The  vulnerable  ppint  on  the  lingual  surface  of  incisors  and 
cuspids  is  the  fossa  formed  by  the  union  of  the  marginal  and  basilar  ridges. 
This  fossa  is  often  deep  and  not  infrequently  presents  a  i3it  or  fissure  in  its 
deepest  portion,  which  sometimes  becomes  the  seat  of  caries,  as  shown  in 
Fig.  327,  A. 

As  a  rule,  in  the  early  stage  of  the  disease  these  cavities  are  much 
deeper  than  they  are  broad.  They  are  usually  marked  at  the  orifice  by  a 
dark  spot,  which  often  extends  to  a  considerable  depth,  but  rarely  in- 
volves the  pulp -chamber. 

In  the  preparation  of  these  cavities  in  the  incipient  stage  of  the  dis- 
ease the  round  bur  is  usually  found  to  be  the  best  instrument  for  the  pur- 
pose.    Retentive  shaping  is  rarely  necessary,  as  the  depth  of  the  cavity 


220 


OPERATIVE    DENTISTRY. 


generally  is  greater  than  its  diameter.  The  margins  of  the  orifice,  however, 
should  be  bevelled  or  countersunk,  as  in  Fig.  327,  B,  by  the  use  of  a  larger 
round  bur,  in  order  to  insure  perfect  adaptation  of  the  filling  and  to  pre- 
vent bruising  or  fracturing  of  the  enamel  edge  during  the  process  of 
introducing  the  gold. 

In  cavities  presenting  the  later  stages  of  the  carious  process,  and  which 
involve  the  greater  i)ortion  of  the  lingual  surface  of  the  tooth  and  com- 
plicated with  an  inflamed  or  devitalized  pulp,  anchorage  may  be  secured 
by  enlarging  the  pulp-canal,  as  shown  in  Fig.  328  ;  the  preparation  should 

Fig.  328. 


Fig.  329. 


Fig.  330. 


After  Dr.  Marshall  Webb. 

be  conducted  upon  the  same  general  principles  as  those  adopted  in  the 
treatment  of  simple  morsal  cavities  in  the  bicuspids  and  molars. 

C  Glass. — Cavities  occurring  upon  the  morsal  edge  of  the  incisors  and 
cuspids  are  very  rare,  except  as  the  result  of  fractures  of  the  enamel  or 
from  mechanical  abrasion  or  attrition.  Fig.  329  shows  such  cavities  in  the 
superior  incisors.  These  cavities  are  usually  quite  shallow,  and  being 
easy  of  access,  no  difficulty  is  experienced  in  their  preparation. 

Care,  however,  must  be  exercised  in  the  preparation  of  the  enamel  mar- 
gins to  extend  the  bevel  to  the  marginal  edge,  so  as  to  prevent  future 
fracturing  of  the  enamel.  Failure  in  this  direction  often  ruins  an  other- 
wise substantial  and  beautiful  operation.  Retentive  shaping  is  also  an 
important  feature  in  this  class  of  cavities.  The  strain  is  often  very  great 
upon  such  fillings,  particularly  in  those  cases  where  the  teeth  have  been 
shortened  by  excessive  mechanical  abrasion  and  the  normal 
length  is  to  be  restored ;  consequently  every  efibrt  should  be 
made  to  give  the  filling  the  greatest  security  by  proper  reten- 
tive shaping.  The  drilling  of  retaining-pits  is  not  to  be  recom- 
mended when  the  location  and  the  extent  of  the  cavity  will 
permit  it  to  be  slightly  enlarged  at  the  bottom.  This  enlarge- 
ment should  extend  in  all  directions,  giving  a  dovetail  or, 
more  correctly,  an  inverted-cone  form  to  the  cavity  (Fig.  330). 
Caries  sometimes  occurs  as  a  result  of  developmental  defects 
in  the  enamel ;  such  cavities  are  to  be  prepared  and  filled  like  other  cavi- 
ties of  the  same  size  and  form. 

Bicuspids  and  Molars. 

D  Class. — This  class  comprises  all  of  those  cavities  which  occur  in  the 
pits  and  fissures  upon  the  morsal  surface  of  the  bicuspids  and  molars. 
Their  location  is  such  that  an  unobstructed  view  can  be  obtained  of  all 
parts  of  the  cavity,  and  they  are  easily  accessible  to  direct  instrumentation. 
The  difficulties  in  operating  are  somewhat  increased  in  the  posterior  part 


THE    CLASSIFICATION    OF    CAVITIES.  221 

of  the  mouth,  especially  in  the  superior  third  molars,  but  with  properly 
curved  excavators,  the  right-angle  hand-piece  and  reflected  light,  the 
preparation  of  such  cavities  becomes  a  comparatively  simple  matter. 

The  loicer  first  bicuspid  usually  presents  the  simplest  form  of  cavity  upon 
the  morsal  surface  of  the  teeth.  The  triangular  ridge  connecting  the 
buccal  with  the  lingual  cusp  is  usually  very  large  and  prominent,  and 
under"  such  circumstances  the  mesio-distal  sulcus  is  not  strongly  marked 
or  is  wanting  altogether.  The  triangular  ridge  forms  with  the  mesial  and 
distal  marginal  ridges  the  mesial  and  distal  pits.  These  pits  are  usually 
the  first  part  of  the  tooth  to  be  attacked  by  caries.  Caries  attacking  the 
pits  form  simple  roundish,  penetrating  cavities,  which  may  be  opened  and 
prepared  separately  with  round  burs. 

On  the  morsal  surface  of  the  upper  first  and  second  Mcuspids,   caries 
usually  begins  in  the  fissure  between  the  cusps  (Fig.  331).     It  sometimes 
presents  as  a  simple  dark  line,  into  which  the  sharp  point  of  an  explorer  will 
hardly  enter,  while  at  a  later  period  the 
cavity  will  have  been  increased  in  size     t^-  ^  >,      ,        ^^'    '   '     ^^   ■  -^ 

•^  Disto-buccal  >**^^        ,  Mesio-buccal 

by  the  undermining  of  the  enamel  and  fissure.  \/^     A/^  fissure. 

the  disintegration  of  its  margins,  so  that  jr^"^^i     sulcus^ 

an  excavator  will  readily  pass  through  ^^'*°"''&t  /-^^_^^  Me^o-iinguai 
the  entire  length  of  the  fissure. 

These  cavities  in  their  earlier  stages  may  be  opened  with  the  tapering 
fissure-burs ;  in  the  later  stage  enamel- chisels  will  be  found  most  useful. 
After  the  cavity  has  been  opened,  the  decay  should  be  thoroughly  removed 
and  a  proper  retentive  shape  given  to  it.  Especial  care  should  be  given 
to  the  terminal  pits  and  to  the  triangular  grooves  or  fissures.  The  latter 
should  be  cut  out  to  their  fullest  extent,  or  until  all  suspicious  tissue  has 
been  removed. 

The  margins  should  then  be  carefully  bevelled  and  the  cavity  is  ready 
for  the  filling  (Fig.  332).  The  student  should  be  cautioned  against  sacri- 
ficing more  of  the  sound  tissiie  than  is  really  necessary  to  gain  the  object  in 
view.  Whenever  possible  the  mesial  and  distal  marginal  ridges  should 
be  maintained  intact,  as  these  bind  the  buccal  and  lingual  cusps  together, 
and  if  they  are  destroyed,  the  crown  is  greatly  weakened  and  the  cusps- 
are  liable  to  be  fractured  and  broken  away.  Sharp  angles  are  to  be 
avoided,  especially  in  the  outline  of  the  cavity  margins.  All  angles 
should  be  rounded  out,  and  the  outline  of  the  cavity  should  present,  when 
finished,  a  series  of  graceful  curves. 

The  morsal  surface  of  the  loicer  second  bicuspid  usually  presents  three 
cusps,  which  are  divided  by  the  triangular  groove,  the  termination  of  each 
arm  of  the  groove  ending  in  a  pit.  The  most  vulnerable  points  in  this  groove 
are  at  its  centre,  where  the  arms  of  the  groove  meet,  and  at  the  terminal 
pits.  Caries  occurring  in  any  part  of  the  groove  will  make  it  necessary 
to  cut  it  out  in  all  directions  as  the  only  way  to  insure  the  tooth  against 
a  recurrence  of  the  disease  in  this  location. 

Upon  the  morsal  surface  of  the  upper  first  and  second  molars  there  are 
two  points  at  which  caries  is  liable  to  occur,  one  known  as  the  mesial 
fossa,  the  other  as  the  distal  fossa,  and  situated  respectively  upon  the  mesial 


222  OPERATIVE    DENTISTRY. 

and  distal  sides  of  the  oblique  ridge  (Fig.  333).  These  fossae  are  sometimes 
traversed  by  a  broad  sulcus  or  a  deep  fissure.  The  fissure  of  the  mesial 
fossa  often  assumes  a  triangular  form.  To  insure  success  it  is  necessary  to 
cut  out  the  fissures  to  their  utmost  limits.  The  instruments  used  for  pre- 
paring these  cavities  should  depend  upon  the  progress  which  has  been 
made  by  the  disease ;  when  limited  in  extent,  small-pointed  fissure-burs 
are  the  best  for  opening  the  cavity  ;  in  the  later  stages  the  enamel-ehisels 
will  be  found  most  useful.  The  margins  should  be  so  prepared  as  to  leave 
smooth,  strong  bevelled  edges  (Fig.  334). 

Occasionally  the  mesial  and  distal  cavities  will  be  found  united  beneath 
the  oblique  ridge.  Under  such  circumstances  the  bridge  between  the 
orifices  of  the  cavities  should  be  cut  away  and  the  two  cavities  converted 
into  one.     Fig.  335   represents  the  prepared   cavity.      The  mistake   of 

Fig.  332.  Fig.  333.  Fig.  334.  Fig  335. 


leaving  the  bridge  of  enamel  and  dentin  between  them  is  often  made,  even 
by  good  practitioners,  but  such  oj)erations  sooner  or  later  come  to  grief, 
either  from  fracture  during  the  operation  of  filling,  or  later  from  the  stress 
of  mastication. 

The  morsal  surface  of  the  upper  third  molar  is  usually  surmounted  by 
only  three  cusps,  and  has,  like  the  lower  second  bicuspid,  a  single  central 
fossa  and  a  triangular  fissure  radiating  from  the  centre  of  the  fossa  and 
passing  between  the  cusps.  This  cavity  should  be  so  prepared  that  when 
finished  it  will  be  triangular  in  form,  with  the  points  of  the  angles  rounded 
out  so  that  the  filling- material  may  be  perfectly  adapted  to  the  walls  and 
margins.  Fig.  336  represents  the  prepared  cavity.  Failure  more  often 
occurs  in  these  cases  than  in  any  other  of  their  class,  for  the  reason  that  the 
fissures  are  not  always  cut  out  to  their  utmost  limit  and  perfectly  sound 
enamel  and  dentin  reached  in  every  part  before  the  filling  is  introduced. 
There  is  also  more  difficulty  experienced  by  the  patient  in  keeping  these 
teeth  perfectly  clean  after  the  operation  ;  especial  care  should  therefore  be 
exercised  to  make  the  operation  as  nearly  perfect  as  possible,  so  that  no 
open  point  of  attack  may  be  teft  for  the  entrance  of  the  micro-organisms 
of  decay. 

The  morsal  surface  of  the  lower  first  and  third  molars  each  present  five 
cusps,— three  buccal  and  two  lingual, — with  sulci  running  between  them. 
A  cavity,  therefore,  occurring  upon  this  surface  and  following  the  sulci 
w.ould  present  a  five-pointed  or  pentagonal  outline  (Fig.  337). 

As  a  rule,  chisels  are  the  most  serviceable  in  opening  these  cavities, 
the  extremities  of  the  fissures  being  followed  with  the  pointed  fissure-bur, 
and  finished  with  larger  round  ones. 

In  following  the  fissure  it  is  better  to  go  a  little  too  far  into  the  sound 
tissue  than  to  fail  to  remove  every  particle  of  the  decayed  or  softened 
dentin  or  enamel.     Thoroughness  in  the  preparation  of  a  cavity  never 


THE    CLASSIFICATION    OF    CAVITIES. 


223 


gives  a  greater  reward  than  in  these  teeth.  Fig.  338  shows  the  finished 
cavity. 

The  morsal  surface  of  the  lower  second  molar  presents  four  cusps  with 
cruciform  sulci  separating  them. 

Caries  is  most  often  found  at  the  point  of  meeting  of  the  sulci  (Fig. 
339,  A). 

In  preparing  a  cavity  of  this  character  the  sulci  should  be  cut  out  to 
their  extreme  limits,  the  sharp  angles  at  the   intersection  of  the  sulci 


Fig.  33;; 


Fig.  336. 


Disto-buccal 
fissure. 


Distal 
fissure. 


Mesio-buccal 
fissure. 


Mesial 
fissure. 


Fig.  338. 


Lingual  fissure. 

rounded  out,  and  the  margins  bevelled.  Sharp  angles,  if  left  at  the  inter- 
section of  sulci,  are  liable  to  be  bruised  and  fractured  during  the  introduc- 
tion of  a  gold  filling  ;  these  angles  should  therefore  be  properly  rounded 
out,  as  shown  in  Fig.  339,  B.  Occasionally  the  morsal  surface  of  the  bicus- 
pids and  molars  will  be  so  extensively  decayed  as  to  involve  the  cusps, 
making  a  large  open  cavity  extending  over  the  whole  morsal  surface  of 
the  tooth.  In  preparing  such  cavities  the  morsal  edge  of  the  cavity  should 
be  first  ground  down  with  corundum  wheels  until  strong  walls  are  reached. 
The  decayed  tooth -structure  should  then  be  removed,  the  cavity  given  a 
shape  as  shown  in  the  illustration  of  the  longitudinal  section  of  a  tooth 


Fig.  340. 


Fig.  341. 


Fig.  339. 

A  B 


Longitudinal  section. 


(Fig.  340),  and  the  edges  of  the  cavity  nicely  bevelled  towards  the  cavity. 
Fig.  341  shows  such  a  cavity  prepared  for  the  filling  in  a  bicuspid  tooth. 

When  the  pulp  is  involved,  this  should  first  be  removed  and  the  canals 
filled,  as  described  in  Chapter  XXVII.  The  pulp-chamber  in  these  cases 
may  be  utilized  for  additional  anchorage. 

E  Class. — This  class  includes  all  of  those  cavities  which  occur  upon  the 
buccal  surface  of  the  bicuspids  and  molars.  Caries  is  rarely  found  upon  the 
buccal  surface  of  the  bicuspids,  except  at  the  cervix.  These  cavities  are 
usually  long  and  narrow,  and  follow  the  line  formed  by  the  free  margin  of 
the  gum,  and  often  extend  beneath  it.    They  are  usually  half-moon  shaped 


224  OPERATIVE    DENTISTRY. 

or  elliptical  in  form,  as  shown  in  Fig.  342,  A,  and  not  infrequently  in- 
volve the  approximal  surfaces  by  their  lateral  extension. 

The  upper  molars  have  nearly  the  same  exemption  from  caries  upon 
the  buccal  surface,  cavities  appearing  most  often  at  the  cervix ;  the  third 
molar  being  more  often  affected  than  the  others.  The  outlines  of  the  cavi- 
ties formed  at  this  point  are  similar  to  those  occurring  in  the  bicuspids. 
Cavities  occurring  upon  the  buccal  surface  which  do  not  involve  the  cervix 
are  usually  long,  narrow,  and  ellii)tical  in  form,  the  long  axis  having  a 
mesio-distal  direction,  as  shown  in  Fig.  343,  A.  Occasionally,  however, 
cavities  wall  be  found  in  the  buccal  groove,  located  well  towards  the  cervix. 
In  the  lower  molars  this  condition  is  much  more  frequently  found,  and  the 
cavities  are  sometimes  quite  large,  extending  to  and  involving  the  morsal 
surface,  forming  a  compound  cavity. 

As  the  disease  extends  it  frequently  passes  beneath  the  free  margin  of 
the  gum,  thus  increasing  the  difficulties  in  preparing  the  cavity  for  the 
reception  of  the  filling.  These  difficulties  may  be  overcome  by  adopting 
those  measures  already  described  in  the  preparation  of  labial  cavities  in 

Fig.  342.  Fig.  343. 

A  B  'a  B 


the  incisors  and  cuspids.  Round  engine  burs  and  spoon  excavators  are 
the  most  suitable  instruments  for  preparing  this  class  of  cavities.  The 
right-angle  hand-piece  will  also  be  found  very  useful  in  preparing  the 
cavities  in  the  molars,  particularly  those  located  in  the  second  and  third 
molars.  The  retentive  form  given  to  them  should  be  that  of  slight  under- 
cuts at  the  base  of  the  cavity,  in  a  line  parallel  with  its  long  axis ;  but 
sometimes  it  is  well  to  make  slight  retention  pits  in  the  mesial  and  distal 
extremities  of  the  cavity.  The  angles  should  be  rounded  out  and  the  mar- 
gins slightly  bevelled,  as  shown  in  Fig.  342,  B,  and  Fig.  343,  B,  in  order 
that  perfect  adaptation  of  the  filling- material  may  be  secured. 

Simx)le  cavities  occurring  in  the  buccal  groove  of  the  upper  and  lower 
molars  should  be  prepared  with  a  slightly  under-cut  form.  The  prepara- 
tion of  those  cavities  which  are  compound  in  their  nature  will  be  described 
under  T  Class. 

F  Class. — Caries  rarely  occurs  upon  the  lingual  surface  of  the  bicuspids. 
The  molars,  however,  present  a  slightly  increased  liability.  Cavities  upon 
the  lingual  surface  of  the  ujyper  and  loiver  molars  occur  in  the  lingual  groove, 
at  the  cervix,  and  in  the  upper  first  molars  in  the  fissure  which  exists  be- 
tween the  mesio-lingual  cingule  or  fifth  cusp,  when  this  is  present,  and 
the  crown. 

The  degree  of  exemption  from  caries  possessed  by  the  lingual  surface 
of  the  bicuspids  and  molars  is  doubtless  due  to  their  smooth  and  rounded 


THE    CLASSIFICATIOX    OF    CAVITIES.  225 

surfaces,  tlie  friction  of  the  tongue  in  speech  and  mastication,  and  the 
more  abundant  presence  of  the  oral  secretions,  which  have  a  tendency  to 
keep  them  clean. 

The  most  common  location  of  caries  upon  .these  surfaces  is  the  Ungual 
groove  of  the  upper  first  molar,  which  often  presents  a  deep  tissure  termina- 
tion in  a  pit  about  midway  between  the  linguo-morsal  margin  and  the 
cervix.  Caries  usually  appears  first  in  the  pit,  and  sooner  or  later  extends 
through  the  entire  length  of  the  fissure,  joassing  over  onto  the  morsal  sur- 
face and  forming  a  compound  cavity.  When  the  groove  is  shallow  and 
not  traversed  by  a  fissure,  the  cavity  is  often  confined  to  the  terminal 
pit. 

Caries  occurring  at  the  cervical  margins  of  the  lingual  surface  of  the 
bicuspids  and  molars  are,  from  the  difficulties  presented  by  their  location, 
often  troublesome  to  properly  prepare  and  fill.  They  should  be  prepared 
and  filled  after  the  same  manner  as  those  cavities  occurring  upon  the 
buccal  surfaces  of  the  same  teeth. 

Cavities  occurring  in  the  fissure  between  the  mesio-lingual  cingule  and 
the  crown  should  be  opened  through  the  entire  length  of  the  fissure  as 
the  only  means  of  preventing  extension  or  a  recurrence  of  the  disease. 
No  especial  description  of  the  preparation  is  necessary  in  this  class  of 
cavities.    They  should  be  treated  and  filled  according  to  general  principles. 

II,    SIMPLE    APPROXIMATE   CAVITIES. 

Incisors  and  Cuspids. 

G  and  S  Classes. — The  location  at  which  caries  most  frequently  occurs 
upon  the  approximal  surfaces  is  not  at  the  actual  point  of  contact  of  these 
surfaces,  but  in  a  location  a  little  nearer  to  the  cervix,  just  beyond  the 
point  of  the  F  formed  by  the  intcrapproximal  space, — in  other  words,  just 
where  fluid  and  semifluid  debris  would  be  held  by  capillary  attraction. 
Another  location  of  caries  of  the  approximal  surfaces  is  just  at  the  margin 
of  the  gum  where  the  festoon  forms  the  base  of  the  interapproximal  space. 
Occasionally  two  such  decayed  spots  will  be  found  upon  a  mesial  or  distal 
proximate  surface  ;  and  it  is  a  very  common  circumstance  to  find  the  ap- 
proximating surfaces  of  the  teeth  decayed  in  exactly  the  same  locations. 

In  the  incisors  and  cuspids  the  carious  spot  is  at  first  round  in  form,  in 

the  bicuspids  oval,  and  in  the  molars  it  is  oblong.    (Jack.)    In  the  later  stages 

of  the  disease  the  cavities  assume  shapes  more  in  accordance 

Fig.  344.   ^^^j^  ^^^^  ^.^^^^^  ^^  ^^^  proximate  surfaces  of  the  tooth, — as,  for 

instance,  in  the  incisors  and  cuspids  the  cavities  will  be  trian- 
gular in  outline,  the  base  of  the  triangle  being  towards  the  cervix, 
as  shown  in  Fig.  344,  while  in  the  bicuspids  and  molars  the  form 
will  be  more  nearly  that  of  a  rectangle. 

The  mechanical  difficulties  presented  in  the  treatment  of 
simple  proximate  cavities  of  the  anterior  teeth  are  only  those  arising  from 
their  inaccessibility.  In  order  to  obtain  an  unobstructed  view  of  the 
cavities,  temporary  separation  of  the  teeth  is  a  necessity.  But  sometimes, 
even  after  thorough  separation,  a  good  view  of  some  parts  of  the  cavity 

15 


226 


OPERATIVE    DENTISTRY. 


cannot  be  secured  without  cutting  away  a  portion  of  either  the  lingual  or 
the  labial  wall.  The  lingual  wall,  for  the  sake  of  the  cosmetic  effect,  should 
be  sacrificed  in  preference  to  the  labial,  as  gold  fillings  upon  the  labial  sur- 
faces are  at  the  best  blemishes  which  seriously  mar  the  beauty  of  the 
natural  tooth.  On  the  other  hand,  if  the  cavity  is  large  and  the  labial 
wall  is  much  weakened,  the  success  of  the  filling,  and  perhaps  the  salva- 
tion of  the  tooth,  will  depend  upon  the  thoroughness  with  which  this 
weakened  wall  is  removed  ;  but,  nevertheless,  care  should  be  exercised  not 
to  remove  more  than  is  necessary  to  obtain  strong  margins. 

Large  cavities  often  come  dangerously  near  to  the  pulp  ;  great  careful- 
ness should  therefore  characterize  the  work  of  their  preparation,  that  this 
organ  may  not  be  exposed  by  an  unneccessary  sacrifice  of  sound  dentin. 

Small  chisels  will  be  found  most  useful  in  opening  all  simple  proximal 
cavities,  while  small  hatchet  excavators  having  bayonet-shaped  shanks,  and 
cow-horn  spoons,  as  shown  in  Figs.  345  and  346,  will,  as  a  rule,  gain  access 

Fig.  345. 


to  all  parts  of  the  cavity  and  permit  the  ready  removal  of  the  decayed 
dentin. 

Bound  burs  of  suitable  sizes  will  be  best  adapted  for  trimming  and 
shaping  the  cervical  margin  of  the  cavity,  which  should  be  so  prepared  as 
to  leave  a  strong  and  but  slightly  under-cut  or  perfectly  flat  wall,  care 
being  taken,  if  the  cavity  reaches  the  cervix,  not  to  leave  a  narrow  rim 
of  enamel  which  would  be  likely  to  be  fractured  in  condensing  the  gold 
against  it.  The  enamel  margins  should  always  be  carefully  bevelled  with 
small  chisels  and  polished  with  file-cut  burs  and  Arkansas  stones.     All 


THE   CLASSIFICATION   OF   CAVITIES, 


227 


Fig.    347. 


angles  should  be  rounded  with  chisels,  burs,  or  stones.     Fig.  347  represents 
the  prepared  cavity. 

Eetentive  shaping  of  these  triangular-formed  cavities  requires  that  three 
points  of  anchorage  be  obtained,  two  at  the  base  of  the  triangle  in  the  angles 
and  one  at  the  apex.     These  may  be  formed  by  deepening  the 
angles  at  the  bottom  of  the  cavity  at  the  cervix  with  a  small, 
round  bur,  and  that  in  the  apex  at  the  morsal  edge  with  a  small 
hatchet  excavator. 

Shallow  undercuts  may  also  be  used  as  a  means  of  retention 
in  the  smaller  cavities.  Retention  grooves,  however,  should 
never  be  cut  in  the  labial  and  lingual  walls,  as  these  weaken  the 
walls  to  a  serious  extent. 

Cavities  which  extend  beneath  the  gum  should  be  treated  beforehand 
by  the  removal  of  the  overhanging  gum  tissue,  so  that  a  clear  aad  unob- 
structed view  of  the  cervical  margin  may  be  obtained. 

Occasionally,  either  from  the  size  or  location  of  the  cavity,  it  approaches 
very  near  to  the  morsal  edge  (Fig.  348,  A),  rendering  the  unsupported 
enamel  very  liable  to  fracture.  Under  such  circumstances  it  is  better  to 
remove  the  weaktiorner  and  convert  the  cavity  into  a  compound  one,  as 
illustrated  in  Fig.  348,  B,  rather  than  to  attempt  its  conservation  and  have 
it  break  away  at  some  future  time  under  the  stress  of  mastication. 


Fig.  348, 
A  B 


Fig.  349. 


Black  has  suggested  as  a  means  of  anchorage  in  these  cases  the  exten- 
sion of  the  cavity  upon  the  lingual  surface  in  the  form  of  a  dove-tail,  as 
shown  in  Fig,  349,  A,  rather  than  by  forming  a  retaining  pit  or  groove  at 
the  morsal  edge  of  the  tooth. 

Such  an  extension  need  not  necessarily  weaken  the  tooth  to  any 
appreciable  degree  if  it  is  not  formed  too  near  the  morsal  edge  or  cut 
too  deeply  into  the  dentin,  while  it  adds  greatly  to  the  retentive  i)ower  of 
the  cavity  at  the  point  where  the  greatest  strain  comes  in  biting  or  during 
mastication. 

Bicuspids  and  Molars. 

I  and  J  Glasses. — Small  cavities  upon  the  mesial  and  distal  surfaces  of 
the  bicuspids  and  molars  present  considerable  mechanical  difficulty  in  their 
preparation.  Figs.  350  and  351  illustrate  cavities  of  this  character.  These 
difficulties,  which  are  mainly  those  of  inaccessibility,  are  greatest  when 
the  teeth  maintain  their  normal  approximation.  They  can,  however, 
usually  be  overcome  by  making  temporary  separation,  the  space  being 
made  as  wide  as  the  circumstances  of  the  case  will  permit.    The  wider  the 


228  OPERATIVE   DENTISTRY, 

space  obtained  the  greater  will  be  the  ease  with  which  these  cavities  can 
be  approached.     Figs.  352  and  353  represent  the  prepared  cavities. 

When  ready  access  cannot  be  attained  in  this  way,  one  of  two  other 
methods  must  be  adopted, — either  to  convert  them  into  compound  cavities 
by  cutting  through  the  morsal  surface  until  the  cavity  is  reached,  or  by  ex- 
tending the  cavity  to  the  buccal  surface.  The  former  of  these  two  methods 
should  receive  the  preference  as  being  the  least  difficult  to  accomplish, 
and  makes  the  strongest  operation  from  the  mechanical  stand-point ; 
whereas  in  the  latter  method  the  difficulties  are  increased  by  reason  of  the 
limited  amount  of  space  in  which  to  operate,  while  the  overlying  enamel  at 
the  morsal  surface  of  the  api)roximo-buccal  angle  will  always  remain  an 
element  of  weakness  as  a  result  of  its  being  undermined  in  extending  the 
cavity  to  the  buccal  surface.  Sometimes,  however,  this  is  the  only  method 
by  which  the  cavity  can  be  reached.  Simple  cavities  upon  the  approximal 
surfaces  of  the  bicuspids  and  molars  more  often  fail  after  being  filled  than 
any  other  class  of  cavities.  This  is  no  doubt  largely  due  to  the  fact  that 
operations  in  these  locations  do  not  permit  of  ready  access  to  all  parts  of 
the  cavity,  and  cannot  therefore  be  so  thoroughly  and  perfectly  prepared 
as  those  in  which  these  difficulties  do  not  have  to  be  ov^come. 

Fig.  350.  Fig.  351.  Fig.  352.  Fig.  353. 


In  the  opening  of  these  cavities  small,  straight,  and  acute-angle  chisels 
will  be  found  very  useful,  while  the  removal  of  the  decay  and  the  prepara- 
tion of  the  margins  can  best  be  accomplished  with  round  burs  in  the 
straight  or  right-angle  hand-piece,  according  to  the  mesial  or  distal  loca- 
tion of  the  cavity. 

Distal  cavities  are  the  most  difficult  to  reach  with  instruments,  and  the 
only  view  that  can  be  obtained  of  them  is  by  reflection  in  the  mouth 
mirror.     This  naturally  adds  to  the  difficulty  in  preparation  and  filling. 

Eetentive  form  may  be  given  to  the  cavity  by  slightly  enlarging  it  at 
its  base,  or  undercutting  at  two  opposite  points.  This  may  be  accom- 
plished with  small  hoe  excavators  of  obtuse  and  acute  angles  and  small 
hatchets. 

In  preparing  and  finishing  the  enamel  margins,  advantage  can  be  taken 
of  the  natural  outward  i^adiation  of  the  enamel- prisms  to  give  the  proper 
bevel  to  the  orifice  of  the  cavity. 

In  large  cavities  upon  the  approximal  surfaces  which  approach  the 
morsal  surface  it  is  best  to  cut  through  this  surface  and  convert  it  into 
a  compound  cavity,  rather  than  to  run  the  risk  of  fracture  of  the  enamel 
at  a  later  period  and  consequent  loss  of  the  filling. 


THE  CLASSIFICATION   OF   CAVITIES.  229 

III.       COMPOUND   CAVITIES. 

Incisors  and  Cuspids. 

K  and  L  Glasses. — Compound  cavities  are  formed  by  the  union  of  two  or 
more  simple  cavities  located  upon  diiferent  surfaces  of  a  tooth.  The  simpler 
class  of  compound  cavities  are  those  located  upon  the  mesio-labial  and  disto- 
labial  surfaces.  Fig.  354  shows  such  cavities  in  the  superior  incisors. 
Teeth  thus  affected  are  generally  of  faulty  organization  and  are  markedly 
predisposed  to  caries.  Such  cavities  are  usually  formed  by  the  joining  of 
an  approximal  cavity  with  one  at  the  cervical  margin  of  the  labial  sur- 
face. Sometimes  the  cavities  will  be  separated  by  a  narrow  isthmus  of 
more  or  less  infected  enamel  or  perhaps  of  sound  tissue.  In  either  case 
the  cavities  should  be  connected,  the  isthmus  cut  away,  and  the  enamel 
edges  straightened  before  the  margins  are  finally  finished  for  the  filling. 
Acute  angles,  uneven  marginal  lines  or  peculiarities  in  form,  are  to  be 
avoided  in  all  operations  that  occupy  a  consi3icuous  position  in  the  ante- 
rior part  of  the  mouth,  for  the  reason  that  things  peculiar  attract  the 
attention  much  more  quickly  than  those  which  follow  the  general  order. 

Temporary  separations  are  commonly  necessary  in  order  to  gain  access 
to  that  portion  of  the  cavity  which  is  located  upon  the  proximal  surface. 

Fig.  354.  Fig.  355.  Fig.  356.  Fig.  357. 


In  the  preparation  of  these  cavities  especial  pains  should  be  taken  with 
the  enamel  margins,  particularly  at  the  cervical  border  and  at  the  angle 
formed  by  the  union  of  the  cavities,  as  these  are  the  points  at  which  fail- 
ures most  frequently  occur  in  this  class  of  fillings. 

Eetention  may  be  secured  by  grooves  cut  in  the  walls  at  the  base  of 
the  cavity,  and  by  a  single  shallow  retaining  pit  at  each  extremity  of  the 
cavity  to  assist  in  starting  the  filling.  Fig.  355  shows  such  cavities  pre- 
pared. 

Separate  descriptions  for  the  preparation  of  these  two  classes  of  cavities 
are  not  necessary,  as  one  does  not  possess  a  peculiarity  which  is  not  com- 
mon to  the  other,  except  that  of  location,  and  this  does  not  materially 
affect  the  method  or  the  difficulties  of  the  operation. 

MandN  Glasses. — Compound  cavities  of  these  classes  are  located  upon 
the  mesio-lingual  and  disto-Ungual  surfaces  of  the  incisors  and  cuspids.  These 
cavities  are  usually  formed  by  the  union  of  a  proximate  cavity  with  one 
occurring  in  the  basilar  pit  or  sulcus  connected  with  it,  as  illustrated  in 
Fig.  356.  Such  cavities  are  most  often  found  in  the  central  and  lateral 
incisors,  and  from  their  location  and  the  relative  inaccessibility  offer  con- 
siderable more  difficulty  in  their  preparation  and  filling  than  those  involv- 
ing the  mesio-labial  or  disto-labial  surfaces.  Fig.  357  represents  the  pre- 
pared cavity.  When  two  simple  cavities  exist  upon  the  proximate  and 
lingual  surfaces  of  these  teeth  which  nearly  approach  each  other,  it  is  better 


230  OPERATIVE   DENTISTRY. 

to  join  them  as  in  the  manner  described  in  K  and  L  Classes,  rather  than 
to  fill  them  as  separate  cavities  with  only  a  narrow  isthmus  of  healthy  den- 
tal tissue  between  them,  for  sooner  or  later  this  tissue  will  be  attacked  by 
caries  and  the  whole  oj)eration  prove  a  disastrous  failure. 

Eetention  is  best  gained  by  undercutting  the  lingual  cavity  and  slightly 
grooving  the  cervical  wall.  Grooves  in  the  labial  or  lingual  walls  of  the 
cavity  are  not  admissible,  as  they  weaken  these  walls  and  increase  the 
dangers  from  fracture.  Occasionally  it  becomes  necessary  to  connect  a 
mesial  and  distal  cavity  with  one  upon  the  lingual  surface.  This  is  to  be 
avoided  whenever  possible,  for  the  reason  that  when  both  of  the  marginal 
ridges  have  been  destroyed  the  crown  of  the  tooth  has  lost  its  strongest 
support,  and  is  very  liable  to  be  fractured  whenever  a  severe  strain  comes 
upon  the  lingual  surface  near  the  morsal  edge. 

O  and  P  Glasses. — Cavities  of  these  classes  are  generally  confined  to  the 
incisor-  teeth,  and  are  formed  by  a  union  of  a  mesial  or  distal  cavity  with 
one  upon  the  morsal  edge.  They  do  not,  as  a  rule,  appear  until  after 
middle  life,  the  morsal  cavity  being  produced  by  attrition  and  gradually 
deepening  until  it  becomes  connected  with  a  proximate  cavity  produced 
by  decay.  Occasionally  through  accident  a  mesio- morsal  or  disto-morsal 
angle  of  a  tooth  is  lost  (Fig.  358),  necessitating  the  formation  of  a  cavity 

Fig.  358.  Fig.  359.  Fig.  360. 


involving  both  the  proximate  surface  and  the  morsal  edge  before  restora- 
tion of  the  lost  part  with  gold  can  be  undertaken. 

The  preparation  of  these  cavities  involves  no  principle  which  has  not 
already  been  emphasized.  Each  cavity  may  be  prepared  separately,  after 
the  manner  already  described,  but  especial  care  should  be  exercised  in  the 
preparation  of  the  angle  formed  by  the  junction  of  the  two  cavities.  The 
labial  portion  should  be  cut  away  just  as  little  as  is  compatible  with 
strength  and  the  removal  of  unsound  tissue.  The  lingual  wall,  which  is 
more  liable  to  be  fractured  by  stress  of  mastication,  may  be  removed  more 
freely  and  its  contour  restored  by  the  filling. 

The  enamel  margins  of  the  morsal  portion  of  the  cavity  should  be  so 
bevelled  that  when  the  filling  is  inserted  they  will  be  protected  by  the 
gold  from  the  dangers  of  fracture.  When  the  enamel  plates  are  very  thin, 
they  should  be  shortened  and  the  normal  length  of  the  tooth  restored  with 
gold.  The-  necessary  retentive  shaping  may  be  obtained  by  slightly  under- 
cutting the  morsal  cavity  and  grooving  the  cervical  wall  of  the  proximate 
cavity.  Additional  retention  may  be  secured  by  forming  shallow  retain- 
ing pits  at  the  opposite  ends  of  the  groove  at  the  cervical  wall. 

In  certain  cases  it  may  become  necessary,  in  order  to  obtain  firm  anchor- 
age for  such  fillings,  to  form  an  extension-arm,  as  shown  in  Fig.  359,  A^ 
or  by  giving  the  extension  a  curved  or  hooked  form.     These  are  ingenious 


THE   CLASSIFICATION   OF   CAVITIES.  231 

methods  of  retention,  and  afford  a  means  of  anchorage,  which  in  many- 
cases,  on  account  of  the  thinness  of  the  tooth,  could  not  be  secured  so 
well  in  any  other  way. 

Q  Class. — Cavities  belonging  to  this  class  are  formed  by  the  union  of 
mesial,  distal,  and  morsal  cavities  in  the  incisors  and  cuspids,  as  shown  in 
Fig.  360.  They  differ  from  O  and  P  Classes  principally  in  extent,  but 
the  peculiarity  of  the  form  of  the  combined  cavities  makes  their  prepara- 
tion and  subsequent  filling  an  operation  requiring  the  greatest  care  and 
skill. 

The  methods  of  preparation  and  the  securing  of  anchorage  are  in 
nowise  different  from  those  employed  in  the  preceding  class  of  cavities, 
but  the  exercise  of  a  trained  judgment  is  nowhere  of  greater  value  or  more 
severely  taxed  than  in  the  proper  preparation  and  filling  of  these  cavities. 
A  thin  or  checked  enamel  wall,  a  deep  undercut,  an  acute  angle,  or  a 
rough  or  improperly  bevelled  margin  are  sufficient  to  cause  the  failure  of 
a-n  otherwise  perfect  operation. 

Bicuspids  and  Molars. 

B  and  S  Glasses. — These  classes  comprise  all  of  those  cavities  in  the  bi- 
cuspids and  molars  which  are  formed  by  a  union  of  mesial  or  distal  with 
morsal  cavities  of  decay,  and  represent  classes  which  are  the  most  common 
and  in  many  ways  the  most  difficult  to  successfully  fill.  Fig.  361  illus- 
trates this  class  of  cavities.  Failures  are  common,  after  a  few  years,  in 
this  class  of  operations,  even  in  the  hands  of  the  very  best  operators ; 
therefore  it  cannot  be  entirely  the  result  of  faulty  manipulation,  as  some 
writers  would  have  the  profession  believe.  The  vulnerable  points  in  fill- 
ings of  this  class  are  the  cervical  margin,  and  "that  margin  which  is 
nearest  to  the  operator  during  the  process  of  the  introduction  of  the  gold." 
(Johnson.)  These  are  the  points  also  which  clinical  experience  teaches 
are  most  often  the  seat  of  secondary  caries,  and  they  are  no  doubt  in  many 
instances  caused  by  imijerfect  preparation  of  the  cavity,  faulty  adaptation 
of  the  gold  to  ihe  cavity  walls,  or  lack  of  proper  restoration  of  the  inter- 
proximal space  by  adequate  contouring. 


Fig.  361.  Fig.  362.  Fig.  363. 


There  are,  however,  other  factors  entering  into  the  causation  of  sec- 
ondary caries  as  impoi'tant  as  those  just  mentioned, — viz.,  the  character  of 
the  tooth-structure,  the  natural  shape  of  the  approximal  surfaces,  the 
hygienic  condition  of  the  mouth,  the  state  of  the  general  health,  the  char- 
acter of  the  secretions,  and  the  activity  of  the  zymogenic  organisms  of 
decay. 

While  these  conditions  are  operative  in  all  parts  of  the  mouth,  the 
latter  are,   nevertheless,  more  active  in  some  locations  than  in  others. 


232  OPERATIVE    DENTISTRY. 

Therefore,  on  account  of  the  greater  difficulties  presented  in  keeping  the 
approximal  surfaces  of  the  bicuspids  and  molars  free  from  food  debris, 
recurrence  of  caries  is  by  that  much  more  liable  to  occur  in  these  loca- 
tions. 

Ordinary  cavities  in  these  locations  present  no  serious  difficulties  either 
in  their  preparation  or  filling. 

Such  fillings,  however,  are  subjected  to  great  mechanical  strain  during 
mastication,  and  therefore  require  to  be  very  firmly  anchored.  Retention 
may  be  secured  by  a  shallow  groove  at  the  cervical  margin  with  shallow 
pits  at  each  extremity  of  the  groove,  and  giving  a  dove-tail  form  to  the 
morsal  portion  of  the  cavity,  as  shown  in  Figs.  361  and  362.  In  molars 
having  mesio-morsal  or  disto-morsal  cavities  firm  anchorage  may  be  secured 
by  extending  the  buccal  or  lingual  fissures,  as  shown  in  Fig.  363. 

Large  cavities,  however,  which  extend  beneath  the  margin  of  the  gum, 
and  have  involved  portions  of  the  buccal,  lingual,  or  morsal  surfaces,  often 
present  difficulties  which  require  a  very  high  order  of  mechanical  knowl- 
edge and  of  manipulative  skill  to  successfully  overcome. 

In  the  preparation  of  all  approximal  cavities  temporary  separations 
are  imperatively  demanded,  and  these  should  be  as  wide  as  the  surround- 
ing conditions  will  permit. 

The  gum,  if  it  overhangs  the  cervical  margin,  should  be  previously 
forced  out  of  the  way  with  gutta-percha  or  cotton.  After  the  cavity 
has  been  roughly  prepared,  the  rubber  dam  should  be  adjusted  and  the 
final  preparation  completed.  The  greatest  care  should  be  exercised  to 
obtain  strong  walls,  rounded  angles,  nicely  finished  margins,  and  firm 
anchorage. 

T  Class. — This  class  of  cavities  is  formed  by  a  union  of  morsal  with 
huceal  cavities  of  decay,  as  shown  in  Fig.  364,  and  are  more  frequently 
found  in  the  lower  molars  than  in  the  upper.  They  have  their  origin  in 
the  x)it  and  developmental  groove  of  the  buccal  surface  and 
Fig.  364.  in  the  fissures  of  the  morsal  surface.  These  cavities  are  often 
found  united  at  their  bases  while  still  separate  at  their  orifices. 
To  insure  a  satisfactory  result  in  filling  such  cavities  it  be- 
comes necessary  to  unite  them  by  cutting  away  the  bridge  of 
tissue  which  connects  their  orifices.  To  attempt  to  conserve 
this  bridge  of  tissue,  which  would  be  more  or  less  infected, 
and  the  enamel  without  the  proper  support  of  sound  dentin, 
would  only  invite  failure  of  the  operation  by  the  danger  from  fracture 
during  the  introduction  of  the  filling,  or  later  under  the  stress  of  force 
applied  in  mastication.  In  those  cases  in  which  the  bases  of  the  cavities 
have  not  been  united  by  the  carious  process,  but  in  which  union  has  taken 
place  at  their  orifices  by  extension  of  the  disease  along  the  buccal  groove, 
care  should  be  exercised  not  to  cut  away  more  of  the  sound  tissue  than  is 
necessary  to  give  proper  retentive  shape  to  the  cavity,  in  order  that  the 
tooth  may  not  be  unnecessarily  weakened.  Strong  walls  and  well  bevelled 
margins  are  nowhere  more  imperatively  demanded  than  in  this  class  of 
cavities,  as  the  strain  upon  these  teeth  during  mastication  is  often  very 
great. 


THE    CLASSIFICATION    OF    CAVITIES. 


233 


TJ  Glass. — Cavities  of  this  class  are  formed  by  a  union  of  a  morsal  with 
a  lingual  cavity  of  decay.  They  are  very  rare  except  in  the  first  and 
second  upper  molars.  They  have  their  origin  in  the  pit  and 
lingual  groove  which  separates  the  mesio-lingual  and  disto- 
lingual  lobes,  and  a  cavity  in  a  fissure  of  the  morsal  surface 
(Fig.  365).  As  a  rule,  these  cavities  do  not  involve  the  lingual 
surface  of  the  crown  to  the  same  extent  that  the  buccal  sur- 
face is  involved  in  the  preceding  class.  Sometimes  the  cavity 
upon  the  morsal  surface  extends  but  very  slightly  upon  the 
lingual  surface,  while  at  others  it  extends  deeply  towards  the 
cervix.  When  the  cavity  upon  the  lingual  surface  is  large,  the  disto- 
lingual  cusp  is  liable  to  be  much  weakened  by  being  undermined.  Under 
such  circumstances  the  cusp  had  better  be  cut  away  and  the  occlusion 
restored  by  contouring.  The  same  general  princij)les  govern  the  prepara- 
tion of  these  cavities  as  in  the  preceding  class. 

V  Class. — Cavities  which  belong  to  this  class  are  formed  by  the  union 
of  mesial,  distal,  and  morsal  cavities  in  bicuspids  and  molars,  as  illustrated 
in  Fig.  366.  The  size  of  the  combined  cavities  is  often  very  large,  and  in 
those  cases  in  which  either  or  both  the  buccal  and  lingual  walls  are  weak, 
it  is  better  practice  to  restore  the  usefulness  of  the 
tooth  by  inserting  a  suitable  artificial  crown  than  by 
the  introduction  of  a  filling  which  in  a  few  years 
would,  in  all  probability,  be  lost  from  fracture  of 
one  of  the  two  remaining  walls  of  the  tooth.  Under 
favorable  conditions,  in  cases  where  the  walls  are 

strong,  a  properly  inserted  filling  would  be  the  best  means  of  restoring  the 
usefulness  of  the  tooth.  I^o  especial  difficulties  surround  the  preparation 
of  this  class  of  cavities  other  than  those  which  arise  from  their  size.  The 
method  of  preparation  is  the  same  substantially  as  that  described  for  E 
and  S  Classes. 

W  Class. — Cavities  of  this  class  are  somewhat  rare  and  are  formed  by  a 
union  of  buccal,  lingmd,  and  morsal  cavities,  usually  in  the  lower  molars. 
These  cavities  do  not  present  as  great  difficulties  in  their  preparation  and 
filling  as  many  of  those  which  have  been  already  considered.  The  same 
general  principle  should  govern  their  j)reparation  and  filling  as  are  indi- 
cated for  T  Class. 


Fig.  366. 


CHAPTEE    XYL 

PEEPARATION   OF   CAVITIES. 

THE^rs^  important  element  in  the  treatment  of  carious  teeth  by  filling 
is  the  proper  preparation  of  the  cavity  for  the  reception  of  the  material 
which  has  been  selected  for  the  purpose  ;  the  second  is  the  introduction  of 
the  filling-material  in  such  a  manner  as  to  hermetically  seal  the  cavity  ; 
and  the  third,  to  so  finish  the  filling  as  to  leave  perfect  margins  and  a  highly 
finished  surface. 

If  these  three  conditions  are  successfully  obtained,  the  operator  has 
fulfilled  his  obligation  to  his  client,  and  if  failure  follows,  it  will  be  due  to 
conditions  of  health  and  local  environments  over  which  he  has  no  direct 
control. 

Guilford  says,  "As  many  fillings  fail  from  lack  of  thoroughness  in  the 
preparation  of  the  cavity  as  from  any  other  cause." 

Ottolengui  asserts,  '^When  a  cavity  is  filled  scientifically  the  tooth  is 
safer  than  ever,  because  the  vulnerable  point  is  now  occupied  by  a  ma- 
terial which  will  resist  destruction  by  caries.  If  decay  occurs  along  mar- 
gins, it  is  because  those  margins  were  improperly  made,  either  as  to 
shape  or  position,  or  else  because  the  filling  was  unskilfully  inserted  or 
finished." 

Black  also  lays  great  stress  upon  the  proper  preparation  of  the  cavity, 
and  enunciated  the  broad  principle  of  extension  for  prevention. 

He  says,  ''A  large  proportion  of  decays  occur  in  the  proximate  sur- 
faces of  the  teeth,  and  for  many  years  it  has  been  noted  that  recurrence 
of  decay  after  filling  is  especially  liable  to  occur  in  these  surfaces.  A 
reason  for  this  has  generally  been  sought  in  some  fault  in  the  management 
of  the  enamel  margins.  The  enamel  margins  about  a  filling  should  always 
be  regarded  as  a  weak  point,  and  should  be  guarded  in  every  possible  way 
against  the  danger  of  a  recurrence  of  decay.  One  great  difficulty  has 
been  that  the  same  rule  of  extension  for  prevention  has  not  been  applied  to 
the  proximate  surfaces  as  has  obtained  in  the  grinding  surfaces.  Exten- 
sion for  prevention  is  extension  of  the  enamel  margin  from  a  line  of  greater 
liability  to  caries  to  a  line  of  lesser  liahility.  Or,  to  change  the  phrase,  it  is 
to  cut  the  enamel  margins  from  lines  that  are  not  self-cleansing  to  lines 
that  are  self- cleansing." 

Parreidt  says,  ' '  One  step  is  as  important  as  the  other.  The  slightest 
defect  in  either  makes  the  result  entirely  questionable.  Thoroughness  and 
especially  care  are  most  important  essentials  expected  of  an  operator  who 
undertakes  filling  of  teeth." 

Tomes,  in  speaking  of  the  importance  of  a  proper  preparation  of  the 
cavity,  says,  "Upon  the  proper  performance  of  this  the  ultimate  success 
of  the  operation  will,  in  great  measure,  depend." 
234 


PREPARATION    OF    CAVITIES.  235 

Statements  of  this  character,  which  are  based  upon  practical  expe- 
rience, might  be  multiplied  almost  indefinitely,  but  a  sufficient  number 
have  been  cited  to  indicate  that  there  is  but  one  opinion  held  upon  the 
subject  by  the  best  authorities. 

The  student,  therefore,  will  be  wise  if  at  the  very  ontset  of  his  profes- 
sional career  he  determines  to  profit  by  the  exijerience  of  those  who  have 
learned — perhaps  by  a  long  series  of  failures — that  the  proper  preparation 
of  the  cavity  is  as  essential  in  the  filling  of  a  tooth  as  are  proper  founda- 
tions in  the  building  of  a  house.  "With  solid  foundations  to  build  upon, 
the  superstructure  may  be  reared  with  the  certainty  that  when  the  stress 
comes  it  will  stand  the  test. 

In  the  preparation  of  a  carious  cavity  for  the  reception  of  a  filling 
each  step  in  the  operation  should  be  thoroughly  and  conscientiously  per- 
formed, so  that  when  it  is  completed  all  infected  tissue  will  have  been 
removed  and  the  cavity  be  in  the  best  possible  condition  for  the  reception 
and  retention  of  the  filling. 

The  general  principles  involved  in  the  preparation  of  cavities  are 
naturally  divided  into  four  progressive  stages  : 

1.  Opening  the  cavity. 

2.  Removing  the  decay 

3.  Retentive  shaping. 

4.  Forming  cavity  margins. 

Opening  the  Cavity. — The  first  step  in  the  preparation  of  all  cavities 
is  to  freely  ox:)en  the  orifice  by  cutting  away  all  overhanging  edges  of 
enamel,  so  that  wherever  possible  the  walls  may  be  readily  approached 
from  all  points. 

Perhaps  the  most  important  step  in  the  preparation  of  carious  cavities 
is  to  cut  away  all  overhanging  enamel  margins  which  are  not  supported  by  sound 
dentin,  for  they  are  always  a  source  of  failure.  The  only  exceptions  to  this 
rule  are  perhaps  a  certain  few  cases  where  the  enamel  is  not  subjected  to 
severe  or  direct  strain  ;  as,  for  instance,  in  proximal  cavities  in  front  teeth 
in  which,  for  cosmetic  reasons,  it  seems  advisable  to  conserve  the  enamel 
of  a  thin  labial  wall.  The  brittle  character  of  the  enamel,  however,  ren- 
ders it  liable  to  be  fractured  whenever  direct  strain  comes  upon  it,  unless 
it  is  supported  by  something  to  counteract  the  strain.  Its  most  natural 
sui^port  is  the  dentin,  but  occasionally  in  such  instances  as  those  just 
mentioned  artificial  support  in  the  form  of  oxyphosphate  cement  may  be 
given  to  it  before  the  introduction  of  a  gold  filling.  The  student  is  warned, 
however,  against  attempting  to  apply  this  method  of  support  in  any  other 
class  of  cases,  as  failure  is  more  than  likely  to  follow  all  such  attempts 
from  the  severe  strain  brought  upon  the  teeth  during  mastication. 

Dr.  Black,  in  his  "Investigation  of  the  Physical  Character  of  the 
Human  Teeth,  etc.,"  demonstrated  in  the  most  positive  manner,  by  elabo- 
rate and  painstaking  experiments,  that  many  of  the  popular  theories 
among  dental  practitioners  in  reference  to  the  density  of  tooth-structure 
in  early  adult  and  advanced  life,  and  their  relative  strength  at  these 
periods,  were  in  many  respects  fallacious.  The  following  table  gives  a 
general  summary  of  the  result  of  his  investigations  upon  these  points : 


236 


OPERATIVE    DENTISTRY. 

General  Summary  op  Results. 


No.  of 

Cases. 

Average 
Age. 

No.  of 
Teeth. 

Specific 
Gravity. 

Per 
cent,  of 
Water. 

Per 

cent,  of 
Lime 
Salts. 

Per 
cent,  of 
Organic 
Matter. 

Average    for   total   number   of 

teeth 

The  highest  percentage 

The  lowest  percentage 

Greatest  variation 

Ill 

32.33 

268 

2.092 
2.133 
2.036 
0.097 

11.06 

13.56 

9..32 

4.24 

63.54 
65.75 
61.08 
4.67 

25.36 
27.59 
23.26 
4.33 

Average  for  persons   under   15 
years  old 

Average  for  persons  15  years  old 

11 
8 
20 
15 
26 
12 
10 
10 

11.00 
17.00 
21.55 
25.93 
33.00 
42.66 
53.00 
63.60 

13 
9 

48 
43 
72 
38 
19 
27 

2.066 
2.080 
2.081 
2.086 
2.092 
2.094 
2.105 
2.019 

11.89 
11.46 
11.47 
11.27 
10.84 
10.91 
10.85 
10.66 

62.26 
63.18 
63.43 
63.44 
63.42 
63.73 
63.83 
64.56 

25.92 
25.33 

Average  for  persons  20  years  old 

25.23 

Average  for  persons  25  years  old 

25.28 

Average  for  persons  30  years  old 

25.66 

Average  for  persons  40  years  old 

25.34 

25.29 

Average  for  persons  60  years  old 

24.81 

Average  for  males  20  years  old 

12 
26 
12 
14 
6 
6 

24 
67 
18 
54 
19 
19 

2.082 
2.0S3 
2.090 
2.094 
2.093 
2.094 

63.30 
63.51 
63.35 
63.48 
63.54 
63.92 

Average  for  females  20  years  old 

Average  for  males  30  years  old 

and  under  40 

Average  for  females  30  years  old 

Average  for  males  40  years  old 

Average  for  females  40  years  old 

0.043 

'  1.29 

2.30 

1.12 

Average  for  persons   who   lost 
their  teeth  from  diseases  of  the 
peridental  membranes 

15 

50.00 

51 

2.101 

10.88 

62.90 

25.19 

Average  for  cases  in  which  the 
teeth  are  classed  as  bad. 

Average  for  cases  in  which  the 
teeth  are  classed  as  good 

Average  for  cases  in  which  the 
teeth  are  classed  as  fair 

Average  for  perfect  teeth 

Average  for  carious  teetli 

32 

63 

16 
42 
91 

28.00 

33.53 

36.19 
36.26 
31.50 

121 

105 

42 
103 
165 

2.087 

2.090 

2.090 
2.095 
2.091 

11.25 

11.16 

10.95 
11.03 
11.06 

63.33 

63.53 

63.56 
63.59 
62.50 

25.49 

25.31 

25.48 
25.36 
25.36 

It  has  been  generally  believed  that  the  teeth  were  very  soft  in  child- 
hood and  increased  in  density  to  old  age  ;  that  the  teeth  increased  in 
strength  from  childhood  to  middle  life  ;  that  the  strength  of  the  teeth  de- 
pended upon  their  density,  and  that  the  density  of  the  teeth,  or  the  per- 
centage of  lime-salts  which  the  tissues  contained,  was  a  controlling  factor 
in  the  liability  to  caries. 

From  the  facts  developed  in  this  investigation  the  following  conclu- 
sions are  drawn  by  Dr.  Black  : 

(1)  "The  teeth  are  strongest  in  youth  and  early  adult  age,  diminishing 
somewhat  in  strength  with  advancing  age." 

This  was  ascertained  first  for  the  dentin  by  applying  the  stress  to  cubes 
eight-hundredths  of  an  inch  square  cut  from  the  dentin  of  permanent 


PEEPAEATION   OF   CAVITIES. 


237 


Exhibit  of  Elasticity  and  Crushing  Stresses  of  Blocks  of  Dentin  Eight-Hundredths 
OF  AN  Inch  Square.     Arranged  according  to  the  Age  of  Persons. 


Case. 

Age. 

Tooth. 

Carious 

or 
Perfect. 

Pulp 

Living 

or 
Dead. 

Specific 
Gravity. 

Per 
cent,  of 
Lime- 
Salts. 

TO  1^ 

IS 

be 

0    . 

bCtn 

246 

9 

/F 

c 

1 

2.069 

62.83 

1.5 

3 

285 

212 

10 

F/ 

c 

1 

2.064 

61.77 

3 

5 

235 

211 

11 

IF 

c 

d 

2.061 

2 

4 

247 

207 

12 

IF 

c 

1 

2.073 

62.40' 

2 

3 

240 

245 

12 

IF 

c 

1 

2.068 

62.4'2 

1.5 

3 

235 

248 

188 

16 

F/ 

c 

1 

2.067 

61.71 

2 

4 

275 

218 

16 

6/ 

c 

d 

2.078 

62.83 

2 

3.5 

225 

244 

16 

IF 

c 

d 

2.080 

63.59 

2 

5 

210 

208 

18 

-     /F 

c 

1 

2.080 

63.65 

3 

5 

210 

230 

210 

22 

H/ 

c 

1 

2.054 

1.5 

3.5 

302.5 

222 

22 

/4 

c 

1 

2.098 

63.80 

2.5 

4.5 

235 

229 

22 

/5 

c 

1 

2.105 

3 

4.5 

245 

221 

23 

/F 

c 

1 

1.100 

64.39 

2 

3 

270 

223 

23 

6/ 

c 

1 

2.085 

63.32 

3 

5 

220 

/6 

c 

d 

2.067 

63.27 

2 

4 

235 

/4 

c 

1 

2.079 

62.72 

2 

4 

270 

228>^ 

24 

/H 

c 

1 

2.068 

2.5 

4.5 

245 

173 

25 

/7 
/8 
/G 

c 
c 
c 

1 
1 
1 

2.110 
2.131 

2.095 

260 
216 
275 

213 

25 

F/ 

c 

1 

2.080 

eii.bi' 

2" 

4" 

280 

216 

26 

/6 

c 

1 

2.099 

63.31 

2 

3 

235 

200 

27 

H/ 

p 

1 

2.098 

64.77 

2 

4 

270 

247 

27 

6/ 

c 

1 

2.104 

64.79 

1 

2.5 

285 

200 

28 

IS 

c 

1 

2.070 

63.19 

1.5 

3 

300 

8/ 

c 

d 

2.043 

62.01 

2 

4 

260 

260 

194 

30 

IF 

c 

d 

2.101 

63.71 

2 

4 

250 

215 

31 

(E 

c 

1 

2.126 

2.5 

4 

245 

/F 

c 

d 

2.117 

2.5 

4.5 

230 

196 

35 

6/ 

c 

1 

2.096 

64.ii" 

2 

4 

2.50 

198 

35 

8/ 

c 

1 

2.123 

64.77 

2 

4 

255 

203 

35 

8/ 

c 

d 

2.082 

63.31 

2 

4 

225 

230 

35 

/5 

p 

I 

2.102 

63.39 

3 

4.5 

265 

3/ 

p 

1 

2.074 

63,27 

2.5 

4.5 

245 

/7 

p 

1 

2.097 

64.63 

2 

4 

252 

7/ 

p 

1 

2.087 

63.94 

3 

5 

250 

217 

36 

7/ 

c 

1 

2.108 

63.77 

5 

8 

200 

242 

202 

40 

/F 

p 

1 

2.072 

63.99 

2 

4 

225 

228 

42 

/H 

c 

1 

2.101 

3 

5 

262 

IE 

c 

d 

2.108 

64.06 

3 

7 

200 

192 

44 

4/ 

p 

1 

2.096 

63.97 

2 

4 

240 

/4 

c 

1 

2.108 

63.74 

3 

6 

250 

/6 

c 

1 

2.068 

62.05 

2.5 

5 

250 

7/ 

p 

1 

2.111 

64.51 

2 

4 

265 

/7 

p 

1 

2.098 

64.26 

2.5 

5 

220 

175 

45 

/3 
/8 
8/ 

c 
c 
p 

d 
d 

1 

2.078 
2.099 
2.085 

183 

178 
225 

231 

47 

F/ 

c 

d 

2.103 

64.13 

3" 

4.5 

200 

227 

49 

G/ 

c 

1 

2.105 

64.53 

3 

5 

220 

224 

193 

50 

6/ 

p 

1 

2.109 

64.66 

2.5 

5 

220 

174 

51 

8/ 

p 

1 

2.123 

207 

250 

51 

/6 

c 

1 

2.103 

64.29 

1.5 

'3    ' 

235 

209 

58 

7/ 

p 

I 

2.100 

63.61 

2 

4 

215 

219 

214 

60 

IF 

c 

d 

2.106 

64.68 

2 

4 

230 

233 

60 

/3 

p 

1 

2.091 

63.78 

2 

4 

200 

3/ 

p 

1 

2.095 

63.84 

2 

4 

215 

/4 

p 

1 

2.088 

62.95 

1.5 

3 

210 

4; 

p 

1 

2.096 

63.22 

2.5 

4.5 

220 

5/ 

p 

1 

2.059 

62.25 

2.5 

5 

195 

6/ 

p 

1 

2.086 

63.59 

2 

4 

200 

/6 

p 

d 

2.093 

63.62 

1.5 

3 

260 

/7 

p 

1 

2.109 

63.94 

2.5 

4.5 

250 

7/ 

p 

1 

2.097 

63.59 

1.5 

3 

2.50 

234 

60 

6/ 

p 

1 

2.122 

64.. 57 

1 

2.5 

290 

195 

61 

3/ 

p 

1 

2.118 

63.07 

2 

5 

260 

8/ 

p 

1 

2.112 

64.16 

2 

4 

235 

/8 

c 

d 

2.113 

64.16 

3 

6 

225 

226. 

63 

/6 

c 

1 

2.104 

68.24 

8 

1.2 

185 

232 

65 

/8 

c 

1 

2.119 

64.10 

2 

3 

215 

227 

Average . . . 

2.09 

4.3 

238 

Number  . . . 

44 

70 

238  OPEEATIVE    DENTISTRY. 

teeth  of  all  ages.  The  instrument  for  applying  and  recording  the  amount 
of  stress  used  was  especially  made  for  this  purpose. 

The  specific  gravity  of  the  dentin  in  all  the  specimens  was  ascertained, 
and  the  percentage  of  lime-salts  also  was  obtained  in  nearly  all,  as  well  as 
the  age  of  the  individual  furnishing  the  specimen,  the  particular  tooth, 
whether  sound  or  carious,  the  condition  of  the  pulp,  whether  vital  or  dead, 
and  all  made  a  matter  of  record,  together  with  the  elasticity  of  the  dentin 
under  stress  at  one  hundred  pounds  to  the  square  inch,  at  one  hundred 
and  fifty  pounds,  and  the  number  of  pounds  at  which  the  block  of  dentin 
crushed. 

A  reference  to  the  foregoing  table  of  results  will  show  the  figures  in 
detail.  It  appears  from  this  exhibit  that  the  average  crushing  stress  of 
dentin  between  the  ages  of  nine  and  twelve  inclusive  is  two  hundred  and 
forty-eight  pounds  to  the  square  inch  ;  between  the  ages  of  sixteen  and 
eighteen  inclusive,  two  hundred  and  thirty  pounds ;  between  twenty-two 
and  twenty-eight  years  of  age,  two  hundred  and  sixty  pounds ;  between 
thirty  and  thirty-six  years,  two  hundred  and  foi'ty-two  pounds ;  between 
forty  and  forty-nine  years,  two  hundred  and  twenty-four  iDOunds  ;  between 
fifty  and  fifty-eight  years,  two  hundred  and  nineteen  pounds ;  between 
sixty  and  sixty-five  years,  two  hundred  and  twenty -seven  x^ounds.  The 
total  average  crushing  stress  was  two  hundred  and  thirty-eight  pounds. 

In  the  table  of  ' '  General  Summary  of  Eesults' '  the  average  specific 
gravity  of  the  teeth  at  eleven  years  was  found  to  be  2.066,  while  the 
average  at  the  age  of  sixty-three  was  2.019,  giving  a  difference  of  forty- 
seven- thousandths  of  a  volume. 

The  increase  in  the  amount  of  lime-salts  follows  the  same  rule.  Be- 
ginning with  62.26  per  cent,  as  the  average  at  eleven  years  of  age,  it  is 
increased  to  64.56  per  cent,  as  the  average  at  sixty-three  years  of  age,  an 
increase  of  2.3  i)er  cent. 

The  enamel  was  found  to  be  very  frail,  the  enamel-rods  chipping  off 
under  very  slight  stress. 

The  blocks  of  enamel,  which  were  the  same  size  as  the  blocks  of 
dentin,  except  that  they  were  only  four-hundredths  thick  (8  x  8  x  4), 
crushed  under  a  stress  of  from  thirty  to  seventy-five  pounds  to  the 
square  inch. 

This  emphasizes  the  need  of  the  greatest  care  being  exercised  in  the 
preparation  of  the  enamel  margins  to  prevent  their  being  injured  after 
the  filling  has  been  inserted,  by  the  stress  of  mastication. 

A  study  of  the  force  of  the  jaws  in  mastication,  which  was  first  under- 
taken by  Patrick  and  Dennis  in  1893,  developed  the  interesting  fact  that 
the  stress  exerted  by  the  jaws  in  biting  was  very  much  greater  than  had 
been  supposed. 

Black  discovered  that  there  was  a  very  great  difference  in  the  stress 
exerted  by  different  individuals,  ranging  in  adults  from  one  hundred  and 
twenty  to  two  hundred  and  seventy  pounds  and  more. 

The  following  table  gives  the  results  of  tests  of  fifty  persons,  ranging 
from  four  and  one-half  years  of  age  to  forty-five  years  : 


PREPARATION    OF    CAVITIES. 


239 


Gnathodynamometer  Records. 


No. 


1 

2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
2-t 
25 
26 
27 
28 
29 
30 
81 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 


Occupation. 


Farmer 

Railroad  passenger  agent 

Railroad  man 

Butcher  

Bookkeeper 

Miss,  seven  years  old 

Servant-girl  

Teacher  

Dentist  

Grocer 

School-girl 

Laborer 

Physician 

Salesman 

Music-teacher 

School -girl 

Temporary  molars 

Merchant 

Music  teacher,  on  bridge 

On  temporary  molars 

Farmer 

Watchman  

Artist 

School-girl   

Chinese  laundryman 

Grocer 

Athlete 

Butcher  

Lawyer 

Blacksmith 

Machinist  

Banker  

Bank  clerk  

Dentist  

Grocer 

Farmer  

Temporary  molars 

School-girl 

Physician 

Printer  

School -girl 

Student 

School -girl 

Physician 

Dentist  

Athlete 


Sex. 

Age. 

Height. 

Weight. 

Incisors. 

M 

25 

5-5 

127 

55 

M 

6 

203 

100 

M 

5-7 

128 

M 

5-9 

1.55 

160 

F 

5-3 

112 

40 

F 

5-5 

90 

85 

F 

7 

3-4 

56 

30 

F 

23 

5-2 

98 

45 

M 

45 

5-2 

140 

100 

M 

38 

5-6 

165 

175 

F 

30 

5-2 

130 

M 

28 

5-9 

140 

85 

F 

18 

5-2 

117 

75 

M 

40 

5-9 

190 

100 

M 

31 

5-6 

180 

75 

M 

22 

5-7 

140 

80 

F 

25 

5-6 

no 

65 

F 

18 

5-6 

110 

50 

F 

24 

5-4 

130 

90 

M 

8 

M 

30 

.5-10 

140 

45 

F 

35 

5-5 

120 

M 

8 

M 

26 

6-3 

200 

60 

M 

25 

5-8 

1.50 

100 

F 

35 

5 

110 

45 

F 

19 

5-11 

123 

60 

F 

24 

5 

110 

45 

M 

5-4 

140 

50 

M 

5-10 

204 

1.30 

M 

6 

230 

70 

M 

30 

5-5 

176 

140 

M 

5-9 

164 

65 

M 

45 

5-8 

195 

45 

M 

40 

5-3 

130 

80 

M 

35 

6 

148 

30 

M 

5-5 

130 

60 

M 

35 

5-8 

220 

45 

M 

5-8 

1.50 

80 

M 

6 

170 

90 

M 

4  k; 

40 

F 

100 

70 

M 

35 

5-11 

205 

M 

32 

5-6 

105 

F 

19 

5-5 

120 

M 

18 

5-8 

130 

70 

F 

5-4 

102 

50 

M 

32 

5-7 

1.35 

M 

40 

5-5 

120 

60 

M 

5-7 

150 

120 

Bicus- 
pids. 


1,30 
185 


Molars 


125 
210 
150 

130 
125 

65 
100 
140 
240 
155 
160 
150 
180 
1.30 
135 
120 

75 
160 

65 
155 
145 

45 
145 
160 

65 
135 

60 
165 
170 
160 
165 
160 
140 
160 

70 

85 
160 
160 
190 

45 
120 
270 

70 
100 

120 

100 
165 


The  application  of  these  facts  to  the  strength  of  the  dental  tissues,  and 
to  the  effect  npon  fillings  and  their  anchorage,  will  result  in  more  careful 
preparation  of  the  enamel  margins  and  more  substantial  anchorage  of 
fillings. 

The  instruments  invented  by  Patrick  and  Dennis  for  measuring  the 
strength  of  the  jaws,  and  later  perfected  by  Dr.  Black,  is  known  as  the 
' '  Gnathodynamometer." 

(2)  ^' Teeth  that  have  lost  their  pulps  and  have  become  discolored  lose 
strength  in  a  marked  degree,  apparently  from  a  deterioration  of  the 
organic  matrix." 

Tests  were  made  of  the  strength  of  fifteen  pulpless  and  discolored  teeth 
from  persons  ranging  from  twenty-five  to  fifty  years  of  age,  all  of  which 
succumbed  to  stresses  between  one  hundred  and  thirty  to  two  hundred 
pounds. 

(3)  '■  '■  Teeth  that  have  become  badly  worn  from  mastication  and  in  ■which 
the  pulps  had  become  so  calcified  as  to  cut  off  the  nutrition  of  the  crown 


240  OPERATIVE    DENTISTRY. 

portion  of  the  dentin,  lose  strength  apparently  from  deterioration  of  the 
organic  matrix." 

(4)  ^  ^  Teeth  of  old  people,  and  especially  those  in  which  much  calcifi- 
cation of  the  pulp  occurs,  deteriorate  in  strength." 

(5)  "There  is  no  basis  for  the  supposition  that  the  teeth  of  children, 
under  the  age  of  twelve  years,  are  too  soft  to  receive  metallic  fillings." 

(6)  ''Differences  in  density,  or  in  the  percentage  of  lime-salts  in  the 
teeth,  is  not  the  controlling  factor  in  the  strength  of  the  teeth  nor  of  their 
hardness,  this  seeming  to  depend  upon  the  condition  of  the  organic 
matrix." 

(7)  ''Differences  in  the  strength  of  the  teeth  have  no  influence  as  to 
their  liability  to  caries.  Differences  in  density  or  in  the  percentage  of 
lime-salts  in  the  teeth  have  no  influence  as  to  their  liability  to  caries." 

(8)  "  The  active  causes  of  caries  is  a  thing  apart  from  the  teeth  them- 
selves, acting  upon  them  from  without,  and  from  a  consideration  of  the 
facts  thus  far  developed,  the  logical  inference  is  that  the  cause  of  the  differ- 
ences in  the  liability  of  individuals  to  caries  of  the  teeth  is  something  in 
the  constitution,  operating  through  the  oral  fluids,  and  acting  upon  the  exciting 
causes  of  caries,  hindering  or  intensifying  its  effects.''^ 

(9)  "Caries  of  the  teeth  is  not  dependent  upon  any  condition  of  the 
tissues  of  the  teeth,  but  on  conditions  of  their  environment." 

(10)  "Imperfections  of  the  teeth,  such  as  pits,  fissures,  rough  or  un- 
even surfaces,  and  bad  forms  of  interproximate  contact,  are  causes  of 
caries  only  in  the  sense  of  giving  greater  opportunity  for  the  action  of  the  causes 
that  induce  caries.^'' 

(11)  "The  objects  to  be  attained  in  filling  teeth  are  the  perfect  exclu- 
sion of  the  causes  of  caries  from  the  tissues  by  sealing  the  cavity,  and 
securing  such  form  as  tcill  prevent  lodgement  of  debris  about  the  margins  of  the 
filling,  and  thus  prevent  the  further  action  of  the  causes  of  caries." 

(12)  "  There  is  no  basis  for  the  supposition  that  some  teeth  are  too  soft 
or  too  poorly  calcified  to  bear  filling  with  gold  or  other  metal  in  use  for  that 
purpose,  since  all  are  found  to  be  abundantly  strong." 

(13)  "There  is  no  basis  for  the  selection  and  adaptation  of  filling- 
materials  to  soft  teeth,  hard  teeth,  frail  teeth  (in  structure),  or  poorly 
calcified  teeth.  What  basis  there  may  be  in  the  conditions  surrounding 
the  teeth  for  the  selection  and  adaptation  of  filling-materials  must  be  left 
to  future  development  to  discover." 

(14)  "  With  our  present  knowledge  the  only  basis  for  the  selection  and 
adaptation  of  filling-materials  to  classes  of  cases  is  the  individual  opera- 
tor's judgment,  as  to  which  he  can  so  manipulate  as  to  make  the  most  per- 
fect filling,  considering  the  circumstances  (environment),  his  own  skill,  and 
the  durability  of  materials." 

(15)  "There  is  no  basis  for  the  supposition  that  calcic  inflammation 
of  the  peridental  membrane,  or  phagedenic  pericementitis  (so-called 
pyorrhoea),  attacks  persons  who  have  dense  teeth  in  preference  to  those 
whose  teeth  are  less  dense." 

(16)  ' '  There  is  no  basis  for  the  treatment  of  pregnant  women  medici- 
nally with  the  view  of  furnishing  lime-salts  to  prevent  the  softening  of 


PREPARATION    OF    CAVITIES. 


241 


Fig.  367. 


Water-syringe  (reduced). 


their  teeth,  or  with  the  view  of  producing  better  calcified  teeth  in  their 
offspring." 

PREPARATION   FOR   OPENING    THE   CAVITY.   . 

Many  operators  are  in  the  habit  of  applying  the  rubber  dam  in  all 
cases  before  commencing  the  operation  of  cavity  preparation.  The  writer 
prefers  to  clear  the  cavity  of  the  thin 
overhanging  enamel  edges,  food  debris, 
and  the  most  softened  portions  of  the 
dentin  before  applying  the  dam,  as 
this  gives  opportunity  for  frequent  use 
of  the  syringe  (Fig.  367)  and  warm 
water    charged    with    antiseptics    or 

alkaline  solutions,  which  often  very  materially  adds  to  the  comfort  of  the 
patient,  and  not  a  little  to  the  sense  of  cleanliness,  as  well  as  relieving  the 
patient  for  a  portion  of  the  time  of  what  is  to  many  the  disagreeable  pres- 
ence of  the  rubber  dam.  Absolute  dryness,  however,  is  always  necessary 
in  the  final  preparation  of  the  cavity,  as  the  exclusion  of  moisture  makes 
it  more  easy  to  locate  slightly  discolored  and  decalcified  dentin. 

The  selection  of  the  instruments  with  which  to  open  the  orifice  of  a 
cavity  will  depend  upon  its  location,  size,  and  accessibility. 

Cavities  located  upon  the  morsal,  lingual,  or  labial  surfaces  of  the  tooth 
crown  are  easily  accessible,  but  those  upon  the  approximal  surfaces  do  not 
give  ready  access  until  after  space  has  been  gained  by  some  of  the  methods 
of  temporary  separation  described  in  the  preceding  chapter. 

Small  cavities  located  upon  any  exposed  surface  can  best  be  opened  by 
the  use  of  some  form  of  small  engine  hur. 

The  forms  of  burs  best  adapted  to  the  opening  of  small  accessible  cavities 
are  the  pointed  fissure,  dentate,  round,  and  inverted  cone.     Figs.  368  and 


Fig.  368. 


•  Fi«sure,  pointed  Dentate. 

369  illustrate  these  forms.  The  pointed  fissure  bur  is  by  far  the  most  service- 
able instrument  for  opening  very  small  cavities  or  fissures.  Its  shape  facili- 
tates its  entrance  into  the  cavity,  while  it  also  more  readily  follows  a  fissure. 
Spear-pointed  drills  are  not  so  serviceable  for  this  purpose,  on  account 
of  the  fact  that  they  are  frequently  broken  by  being  caught  in  the  irregu- 
larities of  the  cavities  or  in  the  fissures. 

16 


242 


OPERATIVE    DENTISTRY. 


In  the  larger  cavities  enamel -chisels  are  much  more  useful  for  opening 
the  cavity,  and  are  less  i)ainful  to  the  patient.     In  using  enamel-chisels 


Fig.  309. 


Round. 


IiiYerted  cone. 


advantage  is  taken  of  the  natural  lines  of  cleavage  of  the  enamel,  as  shown 
in  Fig.  370,  a,  h.     The  overhanging  edges  of  the  enamel  are  thus  rapidly 


Fig.  370. 


Diagram  Illustrating  cleavage  of  the  enamel  and  lines  upon  which  the  margin  should  be  cut  prepara- 
tory to  filling,  a,  chip  thrown  off  by  the  chisel ;  h,  position  of  the  chisel  in  splitting  off  overhanging 
margins ;  c,  c,  correct  lines  upon  which  to  cut  the  margins  preparatory  to  filling ;  d,  d,  incorrect  lines  for 
the  preparation  of  the  margins  for  filling  ;  /,  cavity  in  the  dentin.    (After  Black.) 

and  effectually  cut  away.     The  selection  of  the  form  and  size  of  the  chisel 
should  depend  upon  the  size,  location,  and  the  accessibility  of  the  cavity. 

Fig.  371. 


A  set  of  three-edged  chisels  recently  invented  by  E.  Parmley  Brown 
(Fig.  371)  are  most  admirable  for  opening  cavities,  enlarging  fissures,  cut- 


PEEPARATION    OF    CAVITIES. 


243 


ting  away  overhanging  edges  of  enamel,  and  trimming  the  cervical  margins 
of  cavities.     Other  forms  of  chisels  are  shown  in  Fig.  372. 

Fig.  372. 


Chisels  may  be  nsed  either  with  hand-pressure  or  by  the  driving  force 
of  the  mallet.  The  sharp,  quick  stroke  of  the  mallet  is  the  most  effectual 
force  to  use  in  cleaving  the  unsupported  edges  of  the  enamel,  while  there  is 
much  less  danger  of  the  instrument  slipping  and  injuring  the  soft  tissues 
of  the  mouth  or  the  pulp  than  when  hand-pressure  is  used. 

The  chisel  should  be  held  between  the  thumb  and  first  two  fingers  of 
the  right  hand,  as  a  pen  is  held,  while  the  ring  and  fourth  fingers  rest 
upon  an  adjacent  tooth  or  some  convenient  part  of  the  face  or  chin,  to 
guard  against  slipping.  This  position  of  the  hand  in  holding  the  chisel 
applies  equally  to  the  engine  hand-piece,  excavators,  mallet  pluggers,  and 
other  small-handled  instruments. 

In  opening  cavities  upon  the  approximal  surfaces  which  have  been 
brought  to  view  by  separating  the  teeth,  and  which  are  sui^erficial  and  of 
limited  extent,  small  round  or  inverted  cone-shaped  burs  will  be  found 
most  useful ;  while  in  cavities  of  larger  size  one  of  the  smaller  sizes  of  the 
Parmley  Brown  chisels,  which  cut  upon  the  sides  as  well  as  the  point,  will 
be  found  advantageous  in  cleaving  the  thin  edges  of  the  enamel.  They 
are  also  especially  useful  in  preparing  approximal  cavities  in  the  incisors 
and  cuspids,  and  for  trimming  enamel  margins. 

Time  will  be  saved  in  the  affcer-procedure  of  removing  the  decay  if  in 


244  •         OPERATIVE   DENTISTRY. 

the  operation  of  opening  the  cavity  the  overhanging  enamel  has  been  at 
once  cut  away  until  sound  dentin  has  been  reached. 

The  unnecessary  sacrifice  of  enamel-tissue  is,  however,  to  be  avoided, 
but  nothing  is  gained  by  temporizing. 

In  the  heroic  use  of  the  enamel-chisel  in  the  first  step  in  the  operation 
of  cavity  preparation  lies  the  secret  of  rapid  excavation,  while  much  pain 
and  fatigue  will  be  saved  to  the  patient  and  better  results  will  follow  than 
by  timid,  half-hearted  measures. 

Removing  the  Decay. — In  removing  the  softened  decalcified  dentin 
from  a  carious  cavity  care  should  be  exercised  to  inflict  as  little  pain  as 
possible.  Its  thorough  removal,  however,  is  absolutely  necessary  to  the 
success  of  the  after-treatment.  The  method  of  operation  to  be  adopted  in 
removing  the  carious  dentin  will  depend  upon  the  character  and  con- 
sistency of  the  disorganized  material  to  be  excavated.  These  characteris- 
tics of  the  decalcified  dentin  may  be  divided  into  three  varieties :  one  is 
white  and  of  chalky  consistency,  another  is  light  brown,  semi- elastic,  or  leathery, 
and  the  last  dark  brown  or  black  and  quite  hard. 

In  the  Jirst  variety,  which  is  characteristic  of  the  most  rapid  form  of 
caries,  the  dentin  is  often  exquisitely  sensitive, 

Spoon-bladed  or  round-bladed  excavators  will  be  found  most  useful  in 
removing  the  decalcified  tissue,  and  the  risk  of  exposing  the  pulp  will  be 
much  less  than  if  engine-burs  are  used,  from  the  fact  that  the  decalcifica- 
tion of  the  tissue  has  many  times  progressed  almost  to  the  pulp  before  the 
cavity  has  been  discovered. 

In  the  second  variety,  having  a  semi-elastic,  leathery  consistency,  exca- 
vators having  round  or  spoon  blades  (Fig  373)  will  also  be  found  most 
serviceable  in  removing  the  carious  dentin. 

This  character  of  decay  is  most  often  seen  in  the  teeth  of  young  people, 
and  is  not  infrequently  very  sensitive.  In  all  operations  for  removing 
carious  dentin,  the  fact  should  be  kept  constantly  in  mind  that  the  most 
sensitive  portion  of  a  tooth  is  at  the  periphery  of  the  dentin,  immediately 
beneath  the  enamel,  and  that  the  dentinal  fibrillse,  in  advancing  from  the 
pulp  to  the  i)eriphery  of  the  dentin,  have  a  direction  which  is  perpendicu- 
lar to  the  surface  of  the  tooth.  Much  pain  may,  therefore,  be  saved  the 
patient  if  at  the  outset  of  the  operation  a  few  bold  sweeps  of  the  excavator 
are  made  around  the  circumference  of  the  cavity  immediately  beneath  the 
enamel,  and  that  all  subsequent  cuts  of  the  excavator,  so  far  as  possible, 
follow  a  line  from  the  centre  of  the  tooth  to  the  periphery,  rather  than 
from  the  periphery  to  the  centre.  In  the  leathery  form  of  carious  dentin, 
many  operators  advise  removing  the  dentin  layer  by  layer,  beginning  at 
the  periphery  of  the  cavity  and  gradually  lifting  them  out  until  all  of  the 
material  of  this  character  has  been  removed. 

The  excavator  should  be  kept  sharp,  and  each  cut  of  the  instrument 
should  be  decided.  Scraping  of  the  sensitive  dentin  is  much  more  painful 
than  a  firm,  decided  cut  that  accomplishes  something.  The  greatest  kind- 
ness that  can  be  shown  a  patient  under  these  circumstances  is  to  be  thorough, 
but  at  the  same  time  rapid ;  and  these  conditions  are  not  inconsistent  to  the 
mind  of  the  bold  but  conscientious  operator. 


PREPARATION   OF   CAVITIES. 


245 


ThoroTigli  excavation  of  a  cavity  comprehends  the  removal  of  all  dis- 
organized  and  infected  dentin.     This  may  not  always  be  done  with  safety 

Fig.  373. 


ni  fi  1?  M  1 1  M  f  s  ff  n 


Excavators. 


to  the  pulp,  but,  as  a  general  rule,  this  procedure  should  be  carried  out. 
There  is  only  one  way  to  determine  when  all  infected  tissue  has  been  re- 
moved, and  that  is  by  the  density  of  the  tissue.    All  soft,  leathery  dentin  is 


246  OPERATIVE    DENTISTRY. 

infected,  but  Miller  has  proved  that  all  partially  decalcified  dentin  is  not 
infected,  as  the  process  of  decalcification  is  always  in  advance  of  the 
presence  of  the  micro-organisms  in  the  tubuli. 

The  meaning  of  the  term  thorough  excavation  would  necessarily,  then, 
depend  somewhat  upon  the  judgment  and  experience  of  the  operator  as 
to  whether  all  infected  tissue  had  or  had  not  been  removed.  The  only 
safe  method,  except  in  the  case  of  nearly  exposed  pulps,  is  to  excavate 
until  sound,  hard  dentin  has  been  reached. 

Partially  decalcified  dentin  may  be  allowed  to  remain  in  the  bottom  of 
the  cavity,  as  recalcification  will  usually  take  place  in  this  tissue,  and 
also  for  the  reason  that  it  will  protect  the  pulp  from  thermal  shock. 
Thorough  disinfection  should,  however,  precede  the  introduction  of 
the  filling.  For  this  purpose  mercuric  bichloride  1  to  500,  carbolic  acid 
ninety-five  per  cent.,  oil  of  cloves,  oil  of  peppermint,  or  listerin,  etc.,  may 
be  used. 

In  the  operation  of  removing  the  decayed  dentin  the  surfaces  of  the 
cavity  should  be  left  as  smooth  as  possible.  Undercuts,  grooves,  or  gen- 
eral unevenness  of  the  walls  of  the  cavity  should  be  avoided,  except  those 
which  are  made  for  the  definite  purpose  of  retention,  as  the  filling- material 
is  more  readily  adapted  to  smooth  walls. 

In  the  tliirdj  or  dai%  hard  variety^  the  carious  process  is  very  slow  and 
sometimes  becomes  arrested  or  self-limited.  In  arrested  caries  the  dentin 
is  always  of  a  darker  color  than  ordinary  dentin,  and  might  be  mistaken 
for  caries  but  for  its  greater  hardness.  It  should  not  be  removed  except 
from  the  margins  of  the  cavity,  where  its  color  would  be  objectionable 
and  prevent  a  clear,  clean  appearance  of  the  finished  operation. 

The  dentin  in  the  dark  variety  of  caries  is  not  more  sensitive  usually 
than  dentin  in  its  normal  state.  Cavities  of  this  character  rarely  penetrate 
to  a  depth  involving  or  jeopardizing  the  integrity  of  the  pulp  ;  conse- 
quently they  are  the  most  favorable  cases  for  restoration  by  plugging  with 
gold. 

Retentive  Shaping. — After  the  cavity  has  been  cleared  of  all  disor- 
ganized and  infected  tissue,  the  next  step  in  the  operation  of  cavity  prepa- 
ration is  to  give  it  such  shape  that  the  filling,  after  it  has  been  inserted, 
cannot  be  mechanically  dislodged  ;  while  at  the  same  time  the  retentive 
shaping  must  not  be  carried  so  far  as  to  weaken  the  walls  or  to  endanger 
the  pulp.  These  points  cannot  be  too  strongly  emphasized,  for  upon  their 
proper  appreciation  and  practical  application  will  largely  depend  the 
future  success  or  failure  of  the  completed  operation.  Upon  a  correct 
application  of  the  laws  of  mechanics  to  the  art  of  filling  teeth  will  de- 
pend the  retention  of  the  filling  after  it  has  been  inserted.  The  shape  of 
the  cavity  must  therefore  be  such  that  the  completed  filling  cannot  be  dis- 
lodged by  mechanical  force  without  fracturing  the  walls  of  the  cavity  or 
cutting  the  filling  into  jDieces. 

It  is  obvious,  however,  that  a  single  method  of  securing  retention  will 
not  suf&ce  for  all  cavities.  Various  methods  must  therefore  be  employed, 
and  their  individual  or  combined  application  must  depend  upon  the 
general  form  and  character  of  the  cavity  to  be  filled ;  but,  as  a  general 


PREPARATION   OF   CAVITIES.  247 

rule,  it  may  be  stated  that  the  cavity  should  be  slightly  larger  at  the 
bottom  than  at  the  orifice. 

In  small  cavities,  however,  in  which  the  depth  is  equal  to  or  greater 
than  the  diameter,  the  walls  may  be  left  parallel  to  each  other,  as  the 
lateral  walls  will  contain  a  sufficient  number  of  uneven  points  to  secure 
retention  of  the  filling. 

In  shai^ing  the  cavity,  care  should  be  used  to  leave  the  walls  as  free 
from  angles  as  possible,  as  there  is  greater  difficulty  in  ada^Dting  the  filling 
to  such  surfaces.  To  this  end  the  excavators  used  should  be  of  the  spoon 
or  rounded  form  and  the  burs  either  round  or  oval. 

The  reverse  of  this  is  true  in  cavities  of  larger  size,  where  the  diameter 
of  the  cavity  is  greater  than  its  depth.  Guilford  formulates  two  rules  to 
govern  these  conditions,  as  follows  : 

'*!.  When  the  depth  of  the  cavity  is  greater  than  the  diameter  of  the 
orifice  jDarallel  lateral  walls  will  prove  retentive. 

''2.  When  the  diameter  of  the  orifice  is  greater  than  the  dejith  of  the 
cavity  the  latter  will  have  to  be  somewhat  enlarged  internally  to*  retain 
the  filling."  ■ 

■  The  first  class  of  cavities  are  usually  found  occurring  in  the  pits,  upon 
the  lingual  surfaces  of  the  superior  incisors,  the  morsal  surfaces  of  the 
superior  and  inferior  bicuspids  and  molars,  the  lingual  surfaces  of  the 
superior  molars,  and  the  buccal  surfaces  of  the  inferior  molars. 

The  second  class  of  cavities  are  found  in  nearly  all  locations  upon  the 
various  surfaces  of  the  crowns. 

In  some  cases  the  cavities  formed  by  decay  will  be  found  to  possess  a 
retentive  form  after  the  carious  dentin  has  been  removed,  but,  as  a  rule, 
retentive  shaping  will  be  required,  making  it  necessary  to  cut  away  more 
or  less  sound  dentin.  Care  should  be  exercised,  hoivever,  not  to  carry  this  part 
of  the  operation  too  far,  as  the  walls  of  the  cavity  would  thereby  be  weak- 
ened, or  the  pulp  encroached  upon  to  such  an  extent  as  to  cause  after- 
trouble.  The  tendency  of  the  student  and  the  young  practitioner  is  to 
carry  retentive  shaping  too  far. 

Beep  undercuts,  grooves,  or  pits  are  not  necessary  to  retain  a  filling. 
These  means  of  retention  are  just  as  effective  from  the  mechanic  stand- 
point if  they  are  of  moderate  depth  as  though  they  were  much  deeper, 
while  the  dangers  from  fractured  walls  or  pulp  irritation  are  greatly 
lessened. 

Approximal  cavities  in  bicuspids  and  molars  should  be  so  shaped  as  to 
secure  as  broad  and  flat  a  foundation  as  possible  at  the  cervical  wall  for 
the  support  of  the  filling.  The  laws  of  engineering  require  that  the  base 
or  foundation  of  a  structure  shall  be  equal  to,  or  greater,  in  surface  area 
than  the  structure  to  be  reared  upon  it.  This  applies  with  as  much  force 
to  filling  teeth  as  to  building  suspension  bridges,  twenty-story  buildings, 
or  Eiffel  towers.  The  greater  the  load  to  be  carried,  the  broader  and 
stronger  must  be  the  foundations  upon  which  the  load  is  to  rest. 

If  this  fact  is  appreciated  and  applied  to  the  preparation  of  this  class 
of  cavities,  there  will  be  many  less  failures  in  approximal  fillings  in  bicus- 
pids and  molars. 


248 


OPERATIVE    DENTISTRY. 


i 


scribed 


Eetentive  forms  may  be  given  to  cavities  by  making  the  bottom  of  the 
cavity  slightly  larger  than  the  orifice ;  by  the  formation  of  shallow  grooves 

at  opposite  points  at  the  base  of  the 
Fig.  374.  cavity ;   by  pits  drilled  at  opposite 

points  ;  or  by  a  combination  of  these 
means  of  retention.  In  compound 
cavities  —  those  involving  two  or 
more  surfaces  —  retention  is  often 
strengthened  by  giving  a  dove-tail 
form  to  one  portion  of  the  cavity. 
Occasionally,  on  account  of  the  loss 
of  tissue,  retention  cannot  be  ob- 
tained by  any  of  the  means  just  de- 
it  then  becomes  necessary  to  secure  the  filling  by 
setting  one  or  more  screw-posts. 

These  posts  may  be  set  upon  opposite  sides  of  the  cavity, 
with  an  inclination  towards  each  other,  or  a  single  post  may 
conserve  the  purpose  of  retention.  Fig.  374  shows  a  set  of 
instruments  for  this  purpose.  In  setting  these  posts,  a  spear- 
pointed  drill  is  used  to  make  the  hole  which  is  to  receive  the 
post ;  this  is  followed  by  a  tap,  cut  with  the  same  thread  as 
that  upon  the  gold  wire  used  for  the  post,  and  of  the  same 
size.  A  post  of  suitable  length  is  then  cut  from  the  wire  and 
set  in  the  hole  prepared  for  it. 

It  is  never  wise  to  set  a  post  or  make  a  groove  or  pit  in  the 
incisal  or  morsal  surfaces  of  the  tooth  or  very  near  the  enamel, 
as  their  presence  tends  to  weaken  this  part  of  the  tooth  and 
makes  fracture  of  the  walls  very  liable  to  occur  under  the 
stress  of  mastication. 

Forming  Cavity  Margins. — This  part  of  the  ojieration  is  also  an  ex- 
ceedingly imx^ortant  one,  from  the  fact  that  without  a  proper  forming  of 
the  cavity  margins  perfect  adaptation  of  the  filling-material  to  the  enamel 
borders  is  an  impossibility,  and  consequently  leakage  soon  takes  place  at 
these  defective  points  and  the  operation  becomes  a  failure.  Another  im- 
portant point  in  the  process  of  shaping  the  margins  of  the  cavity  is  to  cut 
away  all  thin  and  weakened  enamel,  for  if  it  is  allowed  to  remain  fracture 
is  liable  to  occur  either  in  adapting  the  filling-material  to  it  or  in  the  stress 
incident  to  mastication. 

In  the  final  preparation  of  cavity  margins,  the  best  results  will  be 
obtained  by  slightly  bevelling  these  borders  by  cutting  the  enamel-rods  in 
an  oblique  direction,  as  shown  in  Pig.  375,  c,  c.  If  the  walls  are  cut  per- 
pendicular with  the  wall  of  the  cavity,  as  in  d,  d,  certain  of  the  enamel- 
rods  would  have  no  support  of  dentin,  and  consequently  they  would  be 
more  liable  to  fracture  from  cleavage  than  if  cut  away  as  shown  in  c,  c. 

In  cavities  occurring  upon  concave  surfaces,  as,  for  instance,  in  the 
fissures  upon  the  morsal  surfaces  of  bicuspids  and  molars,  the  lines  of 
enamel  cleavage  would  have  an  inward  direction,  the  reverse  of  that  shown 
at  d.    The  bevel,  therefore,  given  to  the  enamel  margins  in  this  class  of 


PEEPARATION    OF    CAVITIES. 


249 


cavities  should — in  order  that  no  enamel-rods  be  left  without  proper  sup- 
port of  the  dentin — be  a  little  greater  than  that  given  to  the  margins  of 
cavities  occurring  upon  convex  surfaces. 

Fig.  375. 


The  instruments  which  are  best  suited  to  the  purpose  of  preparing  the 
enamel  margins  are  chisels,  broad- face  hoe  excavators,  barrel- shaped  file- 
cut  burs,  and  Arkansas  stones.  The  margins  should  be  left  as  smooth  as 
possible,  but  in  the  use  of  the  burs  and  stones  care  must  be  exercised  not 
to  round  the  edges  of  the  margins,  as  this  would  leave  a  feather-edge  to 
the  filling  after  it  was  finished,  and  would  be  liable  to  peel  up  or  become 
rough,  thus  spoiling  the  appearan(;e  of  the  marginal  contact  and  opening 
the  way  for  the  establishment  of  secondary  caries. 


CHAPTER   XVII. 

TREATMENT   OF   CAEIES   BY   OBTUEATIONj    OR   FILLING. 

Definition. — Obturation  (from  the  Latin  obturare,  to  stop  up),  the 
act  of  stopping  a  hole  or  covering  an  opening. 

"  Obturation  of  the  Teeth. — The  filling  of  cavities  in  the  teeth  pro- 
duced by  caries  with  a  substance  capable  of  resisting  the  destructive 
action  of  fluids  or  the  force  of  mastication." 

The  operation  of  removing  disorganized  substances  from  a  carious  tooth 
and  mechanically  filling,  stopping,  or  plugging  the  cavity  should,  strictly 
speaking,  be  termed  an  obturation,  and  the  inserted  filling  an  obturator. 

Custom,  however,  sanctions  the  use  of  the  term  filling,  etc.,  as  applied 
to  the  closing  of  a  cavity  in  a  tooth,  and  generally  restricts  the  use  of  the 
term  obturation  to  the  mechanical  procedure  of  stopping  or  covering  an 
opening  in  other  tissues  caused  by  developmental  defects,  disease,  acci- 
dent, or  surgical  operation,  and  of  obturator  to  the  instrument  or  appli- 
ance which  closes  or  stops  the  opening. 

The  introduction  of  a  filling-material  into  a  prepared  cavity  in  a  tooth 
is  a  purely  mechanical  procedure,  but  one  which,  nevertheless,  with  certain 
materials,  like  gold-foil,  calls  for  a  high  degree  of  mechanical  ability  and 
manipulative  skill.  Upon  the  possession  of  these  qualifications  will  de- 
pend, in  no  small  degree,  the  success  or  failure  in  saving  the  teeth  by  the 
operation  of  filling.  It  matters  not  how  perfectly  the  cavity  may  have 
been  prepared,  if  the  completed  filling  is  faulty  in  its  adaptation  to  the  walls 
of  the  cavity  and  the  enamel  margins, — in  other  words,  does  not  hermetically 
seal  the  cavity, — or  the  margins  are  not  perfectly  finished,  or  the  surface  is 
rough  or  not  properly  contoured,  the  final  result  will  be  failure. 

The  main  objects  in  introducing  a  filling  into  a  prepared  cavity  are  to 
arrest  the  further  progress  of  the  carious  process  and  to  restore  the  tooth 
to  its  original  form  and  usefulness. 

The  consideration  of  the  ways  and  means  by  which  these  results  may 
be  obtained  must  comprehend, — 

(a)  The  age  of  the  individual ;  the  character  of  the  teeth  ;  the  condi- 
tion of  the  health,  and  the  local  environment ;  also, 

(b)  The  nature  and  physical  characteristics  of  the  substances  used  as 
filling-materials. 

(c)  Their  capabilities  of  perfect  adaptation  to  the  walls  of  the  cavity 
and  the  restoration  of  contour. 

(d  )    Their  conductivity  and  therapeutic  action  upon  tooth-structure. 

(e)     Their  resistance  to  chemical  action  and  mechanical  abrasions  ;  and, 

(/)  Their  harmony  of  color  with  tooth-tissue. 

In  the  selection  of  the  material  with  which  to  successfully  fill  a  tooth 
an  experienced  judgment  is  required.  This  judgment  in  any  given  case 
must  be  based  upon  a  full  knowledge  and  appreciation  of  all  the  condi- 
tions presented  by  the  individual  to  be  operated  upon,  as  well  as  the 
250 


TREATMENT    OP   CARIES    BY    OBTURATION,    OR    FILLING.  251 

nature,  physical  characteristics,  and  adaptability  of  each  of  the  various 
materials  that  are  generally  used  for  this  purpose.  In  a  wise  selection  of 
the  material  to  be  used  in  each  individual  case  lies  one  of  the  most  im- 
portant elements  in  the  conservation  of  decayed  teeth. 

The  dentist  who  fails  to  appreciate  this  fact  will  fall  far  short  of  render- 
ing the  best  possible  service  to  his  patients. 

FILLING- MATERIALS   AND   THEIR   INTRODUCTION. 

The  materials  which  are  used  for  filling  teeth  are  divided  into  two 
general  classes, — viz.,  non-plastics  and  plastics. 

The  non-ploMics  include  all  of  the  various  forms  of  gold-foils,  sponge  or 
crystal  gold,  platinum  gold-foil,  and  tin-foil. 

The  plastics  are  amalgams,  gutta-percha,  and  the  various  basic  oxide 
cements. 

The  ideal  filling-material,  like  the  "fountain  of  life,"  still  lies  within  the 
realm  of  the  undiscovered.  No  substance  or  combination  of  substances 
yet  discovered  possesses  all  of  the  features  and  characteristics  necessary 
to  fulfil  the  requirements  of  the  ideal  material  for  filling  teeth.  Such  a 
filling  must  be  indestructible  in  the  fluids  of  the  mouth,  and  not  suscep- 
tible to  chemical  change  in  the  presence  of  substances  which  enter  the 
mouth  as  aliment  or  as  medicinal  remedies  ;  it  must  be  easy  of  adaptation 
and  capable  of  making  a  moisture-tight  plug ;  it  must  be  so  dense  in 
structure  as  to  retain  its  form  and  resist  the  abrasion  of  mastication  ;  capa- 
ble of  being  colored  to  match  any  shade  of  the  natural  teeth,  and  polished 
or  glazed  to  imitate  the  enamel ;  it  must  be  a  non-irritant  and  a  non-con- 
ductor of  thermal  changes  ;  incapable  of  shrinkage  or  of  staining  the 
tooth-structure,  and  possessed  of  such  adhesive  and  cohesive  qualities  as 
will  retain  it  in  any  imaginable  location  and  permit  of  the  most  elaborate 
contouring  ;  and,  finally,  it  should  possess  such  therapeutic  properties  as  to 
make  it  preservative  of  tooth-structure. 

NON-PLASTIC   MATERIALS. 

Gold. — Of  all  the  materials  that  have  thus  far  been  used  for  filling 
carious  cavities  in  the  human  teeth  none  possess  in  so  high  a  degree  so 
many  of  the  desiderata  of  a  perfect  filling-material  as  gold,  and  yet  this 
material  falls  far  short  of  the  ideal. 

Gold,  nevertheless,  by  reason  of  its  peculiar  physical  properties,  occu- 
pies the  first  place  among  the  materials  which  are  used  for  this  purpose, 
and  experience  teaches  that  after  all  the  constitutional  and  local  conditions 
and  environment  are  considered,  gold  in  the  majority  of  instances  is  the 
most  reliable  material  with  which  to  preserve  the  teeth  and  restore  portions 
lost  by  disease  or  accident  that  the  dentist  at  the  present  time  has  at  his 
command. 

PHYSICAL   CHARACTERISTICS   OF   GOLD. 

Until  the  publication  of  the  experiments  of  Dr.  Black  with  regard  to 
the  "Physical  Characteristics  of  Filling-Materials,"  very  little  was  known 
of  the  behavior  of  gold  and  gold  fillings  under  stress,  such  as  would  be 
exerted  in  the  mastication  of  foods. 

In  order  to  obtain  data  that  would  be  reliable  this  investigator  began 


252 


OPEEATIVE   DENTISTRY. 


his  experiments  with  cast,  hammered,  and  annealed  gold  of  the  same  purity 
as  that  used  by  the  dentist  in  filling  teeth.  The  object  of  this  was,  first, 
to  determine  the  amount  of  their  strength  and  flow  under  stress  of  a  given 
number  of  pounds,  and  then  to  compare  these  results  with  the  strength  of 
fillings  made  from  the  various  preparations  of  gold-foil,  etc.,  by  the  differ- 
ent methods  of  manipulation. 

Strength  of  Gold. — Blocks  were  prepared  from  bars  of  cast  and  ham- 
mered gold  by  turning  in  a  lathe  to  an  even  size  of  one-hundred-and-forty- 
thousandths  (fourteen  one-hundredths)  of  an  inch,  and  cutting  pieces  from 
the  bar  of  the  lengths  which  appear  in  the  accompanying  table,  the  ends 
being  accurately  squared.    The  specific  gravity  varied  from  19.1  to  19.3. 

These  were  then  subjected  to  compression  in  a  dynamometer  with  a 
micrometer  attachment.  The  pieces  were  placed  with  their  squared  ends 
between  two  parallel  planes  of  steel,  and  the  shortening  of  the  blocks  un- 
der a  stress  of  two  hundred  pounds  and  three  hundred  pounds  noted. 

The  same  sections  of  hammered  gold  were  afterwards  annealed  and 
again  subjected  to  the  same  stress,  with  the  result  of  finding  them  much 
softer  and  much  more  yielding  to  the  same  pressure  or  stress.  This  is  also 
shown  in  the  table. 


Exhibit  of  the  Strength  of  Cast,  Hammered,  and  Annealed  Gold  under 

Compression. 


All  results  reduced  to  the  basis  of  one-teu'th 

0) 

a 

c 

'53 

Per  cent,  of  shortening 
under  a  stress  of 

200  lbs. 

300  lbs. 

350  lbs. 

Case  1.    Cast  gold,  chemically  pure.   Specific  gravity, 
19.2 ;  diameter,  140. 

1 
2 
3 
4 

108.5 
107.5 
107.25 
106.0 

486.9 
481.9 
479.8 
477.8 

4.24 

4.27 
3.91 
5.07 

9.22 
12.16 
11.76 
11.70 

4.37 

11.21 

Case  2.    Cast  gold,  chemically  pure.   Specific  gravity, 
19.25 ;  diameter,  120. 

1 
2 
3 
4 

86.0 

101.0 

98.0 

83.0 

284.2 
339.7 
316.4 

274.5 

1.79 
4.08 
2.62 
L85 

8.39 
8.66 
9.36 
9.30 

13.18 
17.34 
14.19 
13.03 

2.58 

8.92 

14.43 

Case  3.    Hammered  gold,   pure.      Specific  gravity, 
19.3 ;  diameter,  140. 

1 
2 

113.0 
121.0 

490.6 
534.3 

0.33 
0.63 

1.35 
2.53 

2.72 
5.07 

0.48 

1.98 

3.89 

The  same  pieces  annealed. 

1 
2 

6.34 
6.01 

12.70 
12.71 

16.23 
16.71 

6.17 

12.70 

16.47 

Case  4.    Hammered  gold.      Specific   gravity,   19.35; 
diameter  of  pieces,  115. 

1 
2 
3 

4 

170.0 
121.0 
122.0 
109.0 

492.0 
372.4 
380.0 
323.5 

0.88 
0.40 
0.40 
0.53 

2.94 
1.64 
1.64 
2.24 

10.00 
6.14 
3.68 
7.13 

0.55 

2.08 

6.73 

The  same  blocks  after  annealing. 

1 
2 
3 
4 

3.14 
6.75 
6.63 
5.06 

12.93 
14  41 
14.16 
13.76 

18.18 
19.36 
19.02 
19.22 

5.39 

13.38 

18.94 

TREATMENT    OF    CARIES   BY    OBTURATION,    OR    FILLING.  253 

Flow  of  Gold. — Dr.  Black  says,  "As  stress  upon  gold  is  increased 
to  a  point  at  whicli  it  begins  to  show  signs  of  failure  or  yielding,  it  begins 
to  flow  or  spread  laterally.  At  first  this  flow  is  very  slow,  but  as  the  stress 
is  increased  the  flow  occurs  at  a  constantly  increasing  ratio." 

He  found,  however,  that  gold  possessed  the  peculiarity  of  irregularity  in 
its  flow  under  pressure,  the  movement  being  rapid  for  a  little  time,  then  stop- 
ping, and  again  flowing.  This  was  observed  to  invariably  occur  no  matter 
how  steadily  the  pressure  was  increased. 

It  is  generally  recognized  that  gold  is  made  stronger  and  denser  by 
hammering  and  rolling.  For  the  purpose  of  comparison  with  cohesive 
gold  fillings,  bars  of  gold  were  hammered  as  thoroughly  as  their  size  would 
permit. 

Hammered  blocks  of  gold  gave  no  evidence  of  flow  at  a  stress  of  one 
hundred  and  fifty  pounds.  The  average  shortening  under  two  hundred 
pounds'  stress  was  0.48  per  cent.;  at  three  hundi^ed  pounds',  1.98  per  cent.; 
at  three  hundred  and  fifty  pounds',  3.89  per  cent. 

To  test  the  strength  and  flow  of  gold  fillings  under  stress,  he  caused  to 
be  made  forty-eight  fillings  of  the  different  preparations  of  cohesive  and 
non-cohesive  gold.  Dr.  Black  made  ten  of  these  himself;  the  other  thirty- 
eight  being  made  by  twelve  different  operators.  These  fillings  were  made 
in  square  and  round  cavities  in  a  steel  apparatus  especially  constructed  for 
the  purpose.  The  greater  number  were  made  in  the  square  cavities,  which 
measured  one-third  of  an  inch  ;  others  in  round  cavities  giving  the  same 
area  in  cross-section,  but  a  considerable  -number  were  made  in  larger 
cavities. 

The  only  fillings  that  showed  a  specific  gravity  greater  than  that  of 
hammered  gold  (19.3  or  19.4)  were  those  made  by  Dr.  Black.  The  first 
two  were  made  with  the  intention  of  obtaining  the  highest  specific  gravity 
possible.  In  one  a  heavy  mallet  was  used,  and  in  the  other  a  hammer,  the 
force  used  being  much  greater  than  would  be  employed  in  filling  a  tooth.  The 
specific  gravity  of  the  first  was  19.38  ;  of  the  second,  19.42.  The  third 
filling  was  malleted  as  would  be  usual  in  making  a  filling  that  would  be 
exposed  to  unusual  stress.  The  specific  gravity  of  this  filling  was  19.18. 
The  specific  gravity  of  the  other  fillings  ranged  from  18.61  to  10.7.  The 
highest  specific  gravity  of  a  cohesive  gold  filling  was  18.61,  and  the  lowest, 
10.7.  The  highest  specific  gravity  of  a  non-cohesive  gold  filling  was  18.2  ; 
the  lowest,  16.9. 

Dr.  Black  found  in  making  test  fillings  of  purely  non-cohesive  gold,  by 
the  old  method  of  wedging  and  hand-pressure,  that  a  sj)ecific  gravity  of 
16. 0  was  about  the  best  that  could  be  done  with  a  force  that  was  admissible 
in  filling  teeth.     These  fillings  went  to  pieces  under  very  slight  stress. 

This  of  course  was  hardly  a  fair  test  of  the  strength  of  non-cohesive 
fillings.  Such  fillings  should  be  tested  under  conditions  similar  to  those 
obtaining  when  they  are  sai)ported  by  the  walls  of  a  tooth  cavity.  There 
is  no  doubt,  however,  that  the  strength  of  these  fillings  under  stress  is 
much  below  that  of  cohesive  gold. 

Dr.  Black  recognizes  this  fact  when  he  says,  "Of  course  it  must  be 
understood  that  fillings  made  of  purely  non-cohesive  gold  depend  upon 


254  OPERATIVE    DENTISTRY. 

the  support  of  the  walls  of  the  cavity  for  their  strength,  and  tests  of  naked 
fillings  are  of  little  value,  but  the  facts  developed  in  this  way  may  be  in- 
structive to  many  in  the  placing  of  non-cohesive  gold  in  the  beginning  of 
fillings  in  proximate  cavities.  It  shows  that  it  must  be  used  in  moderate 
amount,  and  so  placed  that  it  will  be  properly  supported,  or  the  strength 
of  the  filling  will  be  notably  impaired." 

Gold  fillings  are  often  required  to  carry  a  stress  of  from  one  hun- 
dred to  one  hundred  and  fifty  pounds,  and  even  more  in  persons  with 
strong  masticatory  apparatus.  Gold  fillings,  in  order  to  successfully  carry 
a  stress  of  one  hundred  pounds  upon  an  area  one-tenth  of  an  inch  square. 
Dr.  Black  thinks,  must  have  a  density  or  specific  gravity  ''of  about  17.0, 
and  be  pretty  well  hardened  by  malleting." 

A  filling  one-tenth  of  an  inch  square,  carrying  a  stress  of  one  hundred 
pounds,  should  have  a  base  equal  to  its  size  to  rest  upon.  Dr.  Black  says, 
"  If  we  obtain  a  flat  gingival  wall  in  a  proximate  cavity  in  a  bicuspid  tooth 
of  only  five-hundredths  of  an  inch  in  breadth  (one-twentieth  of  an  inch) 
it  will  have  to  be  full  two-tenths  of  an  inch  long  for  the  gold  placed  upon 
it  to  support  one  hundred  pounds'  stress,  and  to  make  it  support  one 
hundred  and  fifty  pounds  is  out  of  the  question." 

In  approximal  cavities  in  bicuspids  and  molars  it  has  been  a  quite 
common  practice  to  groove  or  undercut  the  buccal  and  lingual  walls  as  a 
means  of  retention  or  anchorage.  This  method  of  preparing  the  cavity 
does  not  place  these  walls  in  a  position  to  assist  in  carrying  the  load,  but 
rather  weakens  them ;  and  if  "the  seat  of  the  filling  is  disturbed  ever  so 
slightly  under  stress,  these  walls  are  liable  to  be  fractured,  or  the  filling  is 
drawn  away  from  them,  thus  destroying  the  object  for  which  it  was  inserted, 
by  permitting  the  entrance  of  the  agencies  of  decay  and  the  ultimate  de- 
struction of  the  filling. 

A  better  method  is  to  prepare  the  cervical  wall  or  base  of  the  cavity 
as  flat  as  possible,  and  the  buccal  and  lingual  wall  without  grooves  or 
undercuts,  and  depend  for  support  of  a  large  part  of  the  stress  by  cutting 
an  additional  seat  in  the  morsal  surface  of  the  crown,  and  so  shape  this  seat 
by  dovetailing  or  other  form  as  to  give  it  good  retentive  powers. 

Platinum-gold  fillings  showed  a  slight  advantage  in  strength  over  those 
made  of  pure  gold  at  the  same  time  and  under  the  same  circumstances, 
but  the  difference  was  not  so  marked  as  was  anticipated. 

The  difference  found  in  the  specific  gravity  of  the  fillings  made  for 
these  experiments  is  explained  by  the  difference  in  the  consolidation  of 
the  gold,  or,  to  state  it  in  another  way,  was  due  to  the  difference  in  the 
number  of  air-spaces  which  the  fillings  contained. 

The  flow  of  gold  fillings,  with  a  specific  gravity  of  17.0  and  above,  under 
the  ordinary  stress  of  mastication  is  so  small  as  to  be  a  matter  of  little 
consequence. 

Under  a  stress  of  one  hundred  and  fifty  pounds  api^lied  to  hammered 
gold  no  evidence  of  flow  was  observed,  while  at  two  hundred  pounds,  a 
stress  entirely  out  of  the  ordinary  during  mastication,  it  was  only  0.48  per 
cent. 

The  surprise,  however,  lies  in  the  fact  that  fifty  per  cent,  of  the  test 


TREATMENT    OF    CARIES    BY    OBTURATION,    OR    FILLING.  255 

fillings,  as  shown  by  the  exhibit,  fell  below  the  indicated  specific  gravity 
of  17.0,  a  density  necessary  to  carry  a  stress  of  one  hundred  pounds  upon 
a  one-tenth-inch  area,  and  could  not,  therefore,  be  expected  to  carry  the 
required  stress,  while  twenty-nine  per  cent,  were  below  15.0  in  specific 
gravity,  and  readily  gave  way  under  a  stress  of  one  hundred  and  fifty 
pounds. 

THE   PROPERTIES   OF   GOLD-FOIL. 

The  properties  of  gold-foil  which  give  it  its  great  value  as  a  filling-mate- 
rial are  its  toughness,  softness,  and  pliability,  which  permit  it  to  be  readily 
adapted  to  the  walls  of  the  cavity  ;  its  tenacity,  which  facilitates  its  intro- 
duction and  consolidation  ;  and  its  resistance  to  mechanical  abrasion.  It, 
however,  possesses  an  objectionable  color,  and  yet  it  is  the  least  objection- 
able in  this  respect  of  all  the  metals  that  are  used  for.  this  purpose. 

Miller  in  testing  for  antiseptic  properties  in  gold-foil  found  that  un- 
annealed  foil — Pack's  pellets  and  Abbey's  foil — retarded  the  growth  of  the 
mouth  bacteria,  while  the  same  gold  annealed  had  no  effect.  Some  prepara- 
tions of  platinum-gold  and  si^onge-gold  acted  in  a  similar  manner. 

Chemically,  gold  is  inert  as  a  filling- material.  It  possesses  no  thera- 
peutic property  upon  tooth-structure,  and  it  is  not  acted  upon  by  any 
substances  which  are  found  within  the  mouth  or  that  enter  this  cavity. 

Gold-foil  as  used  by  the  dentist  for  filling  teeth  is  prepared  in  two  dis- 
tinct forms,  which  are  distinguished  from  each  other  by  the  terms  cohesive 
and  non- cohesive.  These  terms  are  applied  to  designate  the  distinctive 
quality  of  which  each  is  possessed. 

Foils  are  manufactured  from  pure  metal  by  the  processes  of  beating  and 
rolling.  Absolute  i)urity,  however,  is  not  essential  in  the  manufacture  of 
foils.  A  small  amount  of  alloy  does  not  injure  the  working  qualities  in 
the  least. 

All  light-weight  foils  are  made  by  beating,  and  heavy  foils  by  rolling. 

The  bullion  is  first  melted  and  poured  into  ingots  of  suitable  size ; 
these  are  then  rolled  into  thin  ribbons  about  one  inch  wide  and  a  little 
thicker  than  ordinary  note-paper,  the  thickness  being  governed  by  the 
weight  of  the  foil  to  be  produced ;  the  ribbons  are  then  cut  into  inch 
lengths,  each  of  which  will  weigh  two,  three,  four,  five,  or  six  grains,  ac- 
cording to  the  weight  of  the  foil  it  is  desired  to  make. 

These  squares  are  then  laid  between  sheets  of  goldbeater' s-skins  made 
from  the  intestines  of  bullocks  ;  vellum  paper  made  to  imitate  the  skins  is 
now  extensively  used  because  of  its  cheapness.  These  skins  are  cut  into 
five-inch  squares,  and  from  one  hundred  and  sixty  to  one  hundred  and 
seventy  of  them  piled  one  u^Don  the  other,  with  a  square  of  rolled  gold 
between  each,  and  the  pile  wrai^ped  in  heavy  parchment,  being  bound 
both  ways,  so  that  all  of  the  edges  are  protected. 

This  package  is  then  placed  upon  a  heavy  stone  block  or  pillar,  three 
feet  high  by  fourteen  to  fifteen  inches  square,  and  resting  upon  a  large 
wooden  block,  which  is  set  in  the  ground  from  three  to  four  feet  to  give 
it  solidity,  the  upper  end  or  face  of  the  stone  pillar  being  smooth  and 
polished.  Then  with  a  heavy,  round-faced  steel  mallet  the  package  is 
beaten  with  heavy  blows,  and  after  each  stroke  of  the  mallet  it  is  turned 


256  OPERATIVE    DENTISTRY. 

one-quarter  around.    The  time  consumed  in  beating  out  sucli  a  package  of 
gold  is  usually  from  two  to  three  hours. 

After  the  foil  has  been  beaten  to  the  desired  thinness,  the  leaves  are 
separated,  trimmed,  and  placed  in  paper  books  ready  for  use. 

Eolled  gold  is  made  by  passing  it  through  specially  prepared  mills  until 
the  desired  thinness  is  obtained. 

All  foils  as  they  come  from  the  beater's- skins  or  from  the  rollers  are 
non-cohesive.  The  cohesive  quality  is  developed  by  a  process  of  slow 
heating  or  annealing. 

The  light-weight  foils  in  both  the  cohesive  and  non-cohesive  forms  are 
those  most  commonly  used,  Nos.  3  to  6,  and  of  these,  ISTo.  4  is  generally 
preferred.     These  numbers  indicate  the  weight  of  each  sheet  in  grains. 

Eolled  foil  varies  in  weight  from  twenty  to  two  hundred  and  forty  grains 
to  the  sheet,  and  is  always  prepared  in  the  cohesive  form.  ISTos.  20  and  30 
are  the  most  popular  at  the  present  time,  although  a  few  years  ago  the 
heavier  foils  were  in  great  demand. 

Cohesive  gold  possesses  in  a  high  degree  the  quality  of  cohesiveness, 
which  causes  the  surfaces  when  brought  in  contact  under  pressui-e  to  cohere 
or  weld. 

A  filling  made  with  this  gold  forms  a  solid  mass,  and  may  be  afterwards 
hammered  or  rolled  into  plate.  This  quality  gives  great  value  to  this 
form  of  gold  as  a  material  for  restoring  the  contour  of  the  teeth,  but  ren- 
ders its  adaptation  to  the  cavity  walls  more  difficult,  as  the  cohesive  quality 
makes  it  work  stiff  and  hard  under  the  plugger. 

Non-cohesive  gold  is  devoid  of  the  cohesive  quality  and  will  not  cohere 
or  weld  under  pressure.  This  quality  of  non-cohesiveness  makes  it  soft 
and  pliable,  and  permits  the  surfaces  of  the  gold  to  slip  or  slide  upon  each 
other  when  under  pressure.  This  form  of  gold  is  valuable  for  the  filling 
of  all  simple  cavities,  by  reason  of  the  fact  that  it  is  easy  of  adaptation  to 
the  walls  of  the  cavity  and  can  be  very  rapidly  introduced. 

The  difference  between  these  two  forms  of  gold  does  not  appear  to  de- 
pend upon  their  degree  of  purity,  but  rather  to  some  trifling  change  in  the 
physical  condition,  the  nature  of  which  is  not  definitely  understood.  If 
non-cohesive  gold  is  thoroughly  annealed  it  becomes  cohesive,  while  if 
cohesive  gold  is  exposed  for  a  time  to  the  atmosphere  it  becomes  non- 
cohesive. 

A  few  drops  of  aqua  ammonia  placed  upon  a  pledget  of  cotton  and  left 
overnight  in  a  box  containing  cohesive  gold  will  render  it  non-cohesive, 
while  the  cohesive  quality  may  again  be  restored  by  annealing. 

The  non- cohesive  quality  would  therefore  seem  to  be  due  to  some  accu- 
mulation or  deposit  formed  upon  the  surface  of  the  foil.  The  process  of 
annealing  appears  to  drive  this  off,  leaving  the  surfaces  absolutely  clean 
and  thus  rendering  the  foil  cohesive. 

Black,  in  experimenting  to  ascertain  the  causes  of  this  peculiarity,  de- 
monstrated the  fact  that  if  gold  foil  is  subjected  to  the  fumes  of  ammonia, 
hydrogen,  hydrogen  carbide,  hydrogen  phosphide,  sulphur,  phosphorus,  or 
sulphurous  acid  gas,  its  cohesive  quality  is  quickly  destroyed.  Annealing 
restored  this  quality  except  in  those  samples  which  had  been  exposed  to 


TREATMENT   OF    CARIES    BY    OBTURATION,    OR    FILLING. 


257 


the  fumes  of  sulphur  and  phosphorus.      In  these  the  cohesive  properties 
of  the  foil  were  permanently  destroyed. 

It  is  therefore  important,  especially  during  the  winter  months,  that 
cohesive  foil  be  excluded  as  much  as  possible  from  the  atmosphere,  which 
is  then  more  or  less  impregnated  with  the  gases  arising  from  the  combus- 
tion of  coal.  He  further  demonstrated  that  the  fumes  of  ammonia  have 
the  power  of  preventing  the  deleterious  effects  of  other  gases  upon  the 
foil,  and  recommended  that  the  foil  be  subjected  to  this  gas  by  keeping  with 
it  in  the  drawer  a  vial  of  ammonium  carbonate. 

I^on-cohesive  foil  was  the  only  preparation  of  gold  used  by  the  earlier 
operators  in  filling  teeth.  Fifty  years  ago  the  cohesive  property  of  gold- 
foil  had  not  been  discovered,  and  yet  what  marvellous  operations  such  men 
as  Westcott,  Dwindle,  Maynard,  Clark,  and  others  were  able  to  make  with 
non-cohesive  foil.  Their  skill  in  the  use  of  this  material  was  really  won- 
derful, for  many  of  them  succeeded  in  making  most  beautiful  contour 
operations  in  approximal  cavities  of  bicuspids  and  molars,  many  of  which 
have  resisted  decay  and  withstood  the  wear  and  tear  of  mastication  for 
several  decades  without  losing  their  beauty  of  form  and  finish. 

These  same  men,  upon  the  discovery  of  the  cohesive  quality  of  gold~ 
foil,  saw  the  great  advantages  to  be  derived  from  the  discovery,  and  adapted 
it  at  once,  to  the  salvation  of 

broken-down  teeth  that  were  ^^^'  ^^^■ 

bej'ond  successful  filling  with  " 

non- cohesive  foil,  and  which 
otherwise  would  have  been 
condemned  to  the  forceps.  So 
enthusiastic  did  some  of  them 
become  that  they  were  not 
content  with  restoring  the 
contour  of  one-half  of  a  tooth, 
but  even  restored  the  whole 
crown.  Restorations  of  this 
character  with  cohesive  gold 
were  later  carried  to  a  very 
high  degree  of  perfection  by 
Dr.  Marshall  Webb.  The  ac- 
companying illustration.  Fig. 

376,  shows  the  extent  to  which  he  carried  such  restorations, 
are  restorations  of  from  two-thirds  to  three-fourths  of  the  crown,  while 
c,  g,  and  h  show  restorations  of  the  entire  crown. 

The  differences  in  the  working  qualities  of  cohesive  and  non-cohesive 
gold-foil  make  it  necessary  to  use  two  distinct  methods  of  operating. 


a,  b,  d,  e,  f, 


NON-COHESIVE   FOIL. 


Non-cohesive  foil  is  best  adapted  to  cavities  which  have/oztr  walls,  such 
as  are  found  upon  any  of  the  free  surfaces  of  the  crown. 

Successful  operations  can  also  be  made  with  it  in  cavities  having  three 

17 


258 


OPERATIVE    DENTISTRY 


good  walls,  as,  for  instance,  in  compound  approximal  cavities  in  the  bi- 
cuspids and  molars. 

Non- cohesive,  wiannealed,  or  soft  foil  is  tlie  most  ductile  of  all  the  forms 
of  gold  used  by  the  dentist,  and  for  this  reason  it  does  not  "ball"  under 
the  instrument,  is  very  readily  adapted  to  the  walls  of  the  cavity,  and 
insures  a  moisture-tight  plug. 

The  method  of  introducing  it  into  a  prepared  cavity  is  to  first  prepare  the 
gold  in  the  form  of  cylinders,  ropes,  ribbons,  or  pellets  of  various  sizes  and 
density,  the  cylinders  and  pellets  a  little  longer  than  the  depth  of  the 
cavity  to  be  filled. 

The  cylinders  are  prepared  by  winding  a  ribbon  of  foil  around  a  small 
Swiss  broach,  the  ropes  by  rolling  a  strip  of  foil  in  a  napkin,  and  the 
pellets  are  made  by  tearing  the  foil  into  small  fragments  and  rolling  them 
between  the  thumb  and  index-finger.  Cylinders,  however,  are  to  be  pre- 
ferred to  pellets,  from  the  fact  that  they  can  be  prepared  with  more  uni- 
formity in  size  and  length  than  is  possible  in  making  pellets.  The  cylin- 
ders should  be  made  of  such  size  and  density  that  several  will  be  required 

Fig.  377. 


to  fill  the  cavity,  and  of  such  length  that  when  jjlaced  upon  their  ends  in 
the  bottom  of  the  cavity  they  will  project  slightly  from  the  orifice.  These 
may  be  obtained  from  the  manufacturer  already  prepared,  as  shown  in 
Fig.  377,  but  the  writer  always  prefers  to  prepare  the  gold  for  each  in- 


FiG.  379. 


Fig.  378. 


Foil-carriers  (reduced). 


Cylinders  and  mats  in 
the  act  of  being  intro- 
duced into  a  crown 
cavity. 


dividual  case  as   it  is  presented  rather  than  to   depend  upon   material 
prepared  in  advance,  as  this  is  very  rarely  just  what  is  required. 


TREATMENT    OF    CARIES    BY    OBTURATION,  OR    FILLING. 


259 


The  cylinders  or  pellets  are  then  placed  in  the  cavity  with  foil-carriers 
(see  Fig.  378),  being  arranged  side  by  side  around  the  circumference  of 
the  cavity  and  condensed  against  its  walls  with  suitable  pluggers.  Other 
cylinders  or  pellets  are  placed  in  like  manner,  and  these  are  condensed 
towards  its  walls  by  the  use  of  the  wedging  process,  and  this  method  con- 
tinued until  the  filling  is  finally  finished  by  a  single  hard- rolled  pellet 
forced  into  the  centre. 

No  instruments  are  better  adapted  for  this  purpose  than  those  shown 
in  Fig.  380,  made  from  patterns  furnished  by  Dr.  Bing. 

Fig.  380. 


Bing  pluggers. 


The  cylinders,  if  the  filling  has  been  properly  introduced,  should  pro- 
ject a  little  above  the  surrounding  tooth  surface.  These  should  now  be 
thoroughly  condensed  by  hand-i^ressure  or  the  mallet.  Large  serrated, 
round-faced  foot-pluggers,  as  shown  in  Fig.  381,  are  the  best  for  this  pur- 
pose, as  pluggers  with  sharp  angles  are  liable  to  pulverize  the  enamel 
margins,  if  by  chance  they  should  come  in  contact  with  them.  Thorough 
condensation,  directed  always  towards  the  cavity  walls,  is  of  the  utmost 
importance  in  finishing  the  fillings.  The  surface  should  next  be  bur- 
nished, also  towards  the  enamel  margins,  and  the  surplus  gold  cut  away 
with  finishing  burs,  stones,  or  the  file,  as  the  location  of  the  filling  may 
make  most  convenient,  and  the  surface  polished  with  sand- paper  disks, 
emery  strips,  and  pulverized  j)uniice-stone  or  rouge,  or  burnished. 


260  OPERATIVE   PENTISTRY, 

Many  operators  who  use  non-coliesive  foil  employ  tlie  hand  mallet  all 
through  the  operation  in  i3reference  to  the  exclusive  use  of  hand-pressure. 
The  stroke  of  the  mallet  is  entirely  different  from  the  tapping  stroke  used 
in  welding  cohesive  foil.  The  object  in  malleting  non-cohesive  foil  is  to 
utilize  to  its  fullest  extent  the  sx)reading  quality  or  flow  of  this 
Fkj,  381.  form  of  gold,  and  this  can  only  be  accomplished  by  a  firm 
f^  driving  blow,  such  as  would  be  used  in  driving  a  nail  of  the 

same  size  as  the  plugger-point  with  which  the  gold  is  being 
packed,  or  it  may  be  expressed  as  a  lingering  stroke  that  follows 
the  plugger  and  remains  upon  it  until  the  force  of  the  impact 
has  been  exerted  to  its  fullest  extent  upon  the  gold  immediately 
beneath  the  plugger.  The  stroke,  however,  must  be  graduated 
to  the  size  of  the  plugger  and  the  strength  of  the  walls  of  the 
cavity,  otherwise  damage  might  be  done  by  driving  the  point 
of  the  plugger  against  the  margins  of  the  cavity  or  fracturing 
its  walls. 

In  compound  approximal  cavities  (mesio-morsal  or  disto-mor- 
sal)  in  the  bicuspids  and  molars  the  filling  is  commenced  at  the 
plugger?  cervical  wall  by  placing  two  or  three  cylinders  side  by  side,  with 
the  ends  projecting  beyond  the  cavity,  and  condensing  them 
against  the  cervical  margin  with  broad-faced  pluggers.  This  process  is  to 
be  repeated  until  the  morsal  surface  is  nearly  reached,  when  the  cylinders 
should  be  condensed  against  the  morsal  margins  with  foot-shaped  pluggers, 
and  the  filling  finally  finished  in  the  centre  with  a  rope  or  a  single  hard- 
rolled  pellet. 

Final  condensation  should  begin  at  the  morsal  surface  and  be  gradually 
carried  over  to  the  approximal,  using  the  round-faced  foot-pluggers  for 
this  purpose.  The  amount  of  contour  obtained  by  this  method  will  de- 
pend upon  the  distance  that  the  cylinders  projected  beyond  the  walls  of 
the  cavity  at  the  approximal  surface  and  the  thoroughness  with  which 
they  were  condensed  in  building  the  filling. 

Many  oi3erators  prefer  to  use  non-cohesive  foil  for  the  base  of  the  cavity 
and  cohesive  foil  for  the  remainder. 

If  this  method  be  pursued  it  will  be  necessary  to  partially  anneal  the 
pellets  which  are  to  form  the  last  layer  of  non-cohesive  foil,  as  by  this 
means  the  cohesive  foil  can  be  welded  to  it.  Or  the  cohesive  foil  may  be 
driven  into  the  surface  of  the  non-cohesive  foil  by  small  wedge-shaped 
pluggers. 

Another  method  is  to  pack  non-cohesive  foil  against  the  walls  of  the 
cavity  and  over  the  margins,  and  finish  the  filling  in  the  centre  with  cohe- 
sive foil.  This  was  a  favorite  method  with  the  late  Dr.  Allport,  and  one 
which  he  practised  for  many  years. 

In  approximal  cavities  in  bicuspids  and  molars  he  always  used  non- 
cohesive  foil  at  the  cervical  margin,  claiming  that  he  secured  a  better 
adaptation  of  the  gold  to  the  cervical  wall  than  was  possible  with  cohe- 
sive foil,  and  that  from  the  fact  that  large  cylinders  or  pellets  were  used 
for  this  purpose,  and  thoroughly  condensed  with  a  broad-faced  foot-shaped 
plugger,  there  was  less  danger  of  injuring  the  cervical  margin  than  when 


TREATMENT    OF    CARIES    BY    OBTURATION,    OR    FILLING.  261 

coliesive  foil  was  used,  as  with  tlie  latter  it  was  absolutely  necessary  to  use 
small  pieces  of  foil  and  condense  them  with  small  pointed  pluggers  to 
secure  perfect  adaptation,  while  the  danger  of  bruising  the  cervical  margin 
was  greatly  increased  by  the  liability  of  the  plugger  to  being  driven 
through  the  gold. 

Hopes  and  ribbons  are  used  by  some  operators  in  preference  to  cylinders 
and  pellets.  These  are  made  from  one  to  two  inches  in  length,  a  sheet  of 
foil  being  cut  into  two  to  four  equal  strips  and  rolled  in  a  napkin  to  form 
ropes,  or  folded  with  a  spatula  to  form  ribbons. 

The  method  of  introducing  the  rope  and  the  ribbon  is  to  grasp  one  end 
of  it  with  the  foil  tweezers  and  carry  it  to  the  bottom  of  the  cavity,  and 
lightly  pack  it  against  the  W2,\\  farthest  from  the  operator,  then  fold  it  over 
and  carry  it  again  to  the  bottom  of  the  cavity,  condensing  it  against  the 
fold  first  inserted,  but  allowing  the  upper  end  to  project  slightly  above  the 
margin  of  the  cavity.  After  the  cavity  has  been  about  half  filled  in  this 
way,  another  rope  or  ribbon  may  be  introduced  in  like  manner  and  packed 
against  the  wall  of  the  cavity  nearest  to  the  operator,  then  against  the  lat- 
eral walls,  and  the  filling  finally  completed  by  packing  and  wedging  an- 
other rope  or  ribbon  into  the  ojjen  space  left  in  the  centre.  The  surface 
is  then  thoroughly  condensed  and  finished  in  the  manner  described  with 
the  use  of  cylinders  and  pellets.  This  method  is  thought  by  some  opera- 
tors to  be  superior  to  the  use  of  cylinders,  for  the  reason  that  the  gold  is 
more  easily  introduced  and  that  it  makes  a  more  compact  filling.  This 
statement,  however,  is  open  to  question  in  both  of  its  features. 

Herbst  Method. — Another  method  of  packing  non-cohesive  gold  is 
that  introduced  by  Dr.  Herbst,  of  Germany,  which  consists  of  adapting 
or  modelling  the  gold  to  the  walls  of  the  cavity  by  means  of  burnishers 
rapidly  rotated  by  the  dental  engine.  The  gold  used  for  this  purpose  was 
a  very  soft  form  of  cylinders  especially  prepared  by  Wolrab,  of  Bremen. 

Fillings  introduced  by  this  method  show  a  most  perfect  adaptation  of 
the  gold  to  the  walls  of  the  cavity,  are  moisture-tight,  as  proved  by  their 
successful  resistance  of  the  carmine  test.  The  surface  of  the  filling  pre- 
sents a  burnished  appearance,  which  is  rendered  very  cohesive  by  the  fric- 
tion and  heat  produced  by  the  process  of  burnishing,  so  that  each  piece  of 
gold  as  it  is  introduced  adheres  to  the  previous  one  which  has  been  bur- 
nished into  its  position.  The  filling  may  be  finished  throughout  by  the 
same  process,  but  better  results  are  obtained  by  finishing  with  cohesive 
gold  condensed  by  the  mallet. 

The  instruments  recommended  by  Dr.  Herbst  for  the  introduction  of 
the  filling  are  shown  in  Fig.  382,  and  consist  of  eighteen  burnishers,  some 
of  steel  and  others  with  blood-stone  points  of  various  form  and  size. 

It  will  be  readily  understood,  however,  that  only  the  most  accessible 
cavities  can  be  successfully  filled  by  this  method  ;  those,  for  instance,  pos- 
sessing four  good  walls,  like  the  morsal  cavities  of  the  molars  and  bicuspids, 
being  the  most  favorably  located  for  this  system. 

For  anchoring  the  filling,  no  especial  preparation  of  the  cavity  is  re- 
quired other  than  that  given  to  cavities  which  are  to  be  filled  with  non- 
cohesive  foil  by  the  other  method. 


262 


OPERATIVE    DENTISTRY 


In  starting  the  filling,  the  first  cylinder  introduced  into  tlie  cavity 
should  be  large  enough  to  cover  the  bottom,  and  it  should  be  carried 
into  position  with  a  round  hand-burnisher,  and  then  followed  with  the 
engine-burnisher   of  the  same   size   and  form,   and  thoroughly  adapted 

Fig.  382. 


Herbst  burnishers 

to  the  floor  of  the  cavity.  Successive  cylinders  are  then  introduced  and 
burnished  against  the  walls  of  the  cavity,  keei)ing  the  edges  next  to  the 
walls  higher  than  the  centre  of  the  filling.  As  the  filling  nears  completion, 
the  cylinders  should  be  so  placed  that  they  can  be  burnished  against^  and 
over,  the  enamel  margins.  The  centre  of  the  filling  can  then  be  finished 
by  adding  other  cylinders  by  the  same  method,  or  with  cohesive  gold, 
condensed  with  foot-pluggers  and  the  mallet.  Fillings  made  by  the 
Herbst  method  are  not  so  dense  as  those  made  with  the  mallet,  and  the 
surface  does  not  wear  so  well,  as  it  shows  a  tendency  to  flake  and  bruise 
under  stress  of  mastication.  Contour  fillings  cannot  be  as  successfully 
made  by  this  process  as  with  cohesive' gold,  and  yet,  by  the  use  of  the 
matrix,  thoroughly  good  approximal  fillings  have  been  introduced  in  the 
bicuspids  and  molars. 

COHESIVE   FOIL. 

Cohesive  or  annealed  foil  is  stiff  and  harsh  as  compared  with  the 
^ Velvety"  softness  of  non-cohesive  foil.  It  does  not  work  so  easily  as 
the  latter,  and  requires  an  entirely  different  method  of  manipulation  for 
its  introduction. 

In  the  manipulation  of  cohesive  foil  the  student  must  keep  in  mind 
two  rules  if  he  would  be  successful  in  its  use  :  first,  always  to  use  small 
pieces  of  gold  ;  and  second,  to  condense  them  with  small  plugger-points. 

Many  faulty  fillings  have  been  made  with  cohesive  gold  by  not  ob- 
serving these  two  important  rules. 

On  account  of  the  cohesive  quality  of  this  form  of  foil  it  has  a  tendency 
to  "ball"  under  the  plugger  and  draw  away  from  the  walls  of  the  cavity  ; 
while  if  used  in  large  pieces  there  is  constant  danger  of  the  mass  clogging 
and  bridging  in  the  cavity,  and  thus  making  a  porous  and  leaking  filling. 

Cohesive  foil  is  prepared  for  introduction  into  the  prepared  cavity  in 
the  form  of  loosely  rolled  ropes,  ribbons,  pellets,  and  mats. 

The  loosely  rolled  ropes  are  made  by  dividing  a  sheet  of  No.  3  or  No.  4 
foil  into  strips  and  rolling  them  in  a  napkin.  Cohesive  foil  should  never 
be  handled  with  the  unprotected  fingers,  as  the  moisture  or  other  impurities 
upon  the  skin  would  destroy  its  welding  properties. 

Pellets  may  be  made  by  cutting  the  ropes  into  lengths  varying  from  one- 
eighth  to  one- fourth  of  an  inch. 


TREATMENT   OF   CARIES   BY   OBTURATION,    OR   FILLING.  263 

Eibboiis  are  made  by  folding  a  slieet  of  the  same  foil  witli  a  spatula  to 
any  desired  width.  Twice  folding  reduces  the  slieet  to  one-fourth  its 
original  width ;  this  may  be  cut  lengthwise  in  strips  or  ribbons  from  one- 
sixteenth  to  one-eighth  of  an  inch  in  width. 

These  ribbons  are  composed  of  four  thicknesses  of  foil,  and  in  this  form 
they  constitute  one  of  the  best  methods  of  introducing  cohesive  foil. 

Mats  are  prepared  by  folding  a  half-sheet  or  a  whole  one  into  a  ribbon 
about  one-eighth  of  an  inch  wide  and  cutting  it  into  suitable  length  for 
use  in  the  case  at  hand.  Eibbons  and  mats  may  also  be  made  from  'No. 
20  or  No.  30  foil  of  a  single  thickness  by  cutting  it  in  strips  of  suitable 
widths  and  lengths. 

Some  operators  prefer  the  rolled  gold  to  the  beaten  when  using  heavy 
foil,  as  it  is  claimed  greater  softness  and  ductility  is  obtained  when  the 
foil  is  prepared  in  this  way. 

Introduction  of  Cohesive  Foil. — In  the  introduction  of  cohesive 
foil,  retention  grooves  or  pits  are  necessary  for  starting  the  filling.  The 
first  piece  of  gold  iatroduced  into  the  cavity  should  be  firmly  anchored  by 
packing  it  into  the  retaining  grooves  or  pits.  This  may  be  accomplished 
by  holding  the  gold  in  position  with  an  instrument  held  in  the  left  hand, 
while  it  is  packed  into  place  with  the  plugger  held  in  the  right  hand  and 
the  succeeding  piece  welded  to  it ;  this  process  being  repeated  until  the 
cavity  is  full. 

Care  should  be  exercised  that  only  a  small  quantity  of  gold  shall  at  any 
time  be  under  the  plugger  for  condensation,  and  that  each  piece  that  comes 
in  contact  with  a  wall  or  margin  of  the  cavity  shall  be  thoroughly  adapted 
to  it  without  bruising  the  tooth-structure.  The  best  results  are  only 
attainable  by  welding  each  lamina  thoroughly  to  the  preceding  one. 
Hastily  made  fillings  are  usually  faulty  in  their  adaptation  to  the  enamel 
margins,  and  sooner  or  later  fail  from  leakage  and  recurrence  of  caries. 

Plugging  Instruments. — Cohesive  foil  can  be  manipulated  either  by 
hand-pressure  or  mallet  force.  The  plugger-points  which  are  required 
for  adapting  this  form  of  gold  to  the  walls  and  margins  of  the  cavity  and 
for  condensation  are  considerably  smaller,  and  the  serrations  much  finer 
than  those  used  for  non-cohesive  gold.  The  forms  which  are  in  the  most 
general  use  are  the  Varney,  Webb,  Darby-Perry,  Chappell,  and  Eoyce, 
as  shown  in  Figs.  383,  384,  386,  387,  and  388. 

Serrated  instruments  are  not,  however,  absolutely  necessary  for  pack- 
ing cohesive  gold ;  smooth  points  answer  equally  well  with  rough  ones. 
Some  operators  use  ivory  points  with  smooth  surfaces,  and  hand-pressure 
entirely  in  packing  cohesive  gold.  The  ideal  surface  for  a  plugger-point 
for  welding  cohesive  gold  is  that  formed  by  breaking  hardened  steel.  The 
nearer  the  serrations  reproduce  the  roughness  of  this  surface  the  nearer 
the  plugger-point  will  approach  the  most  perfect  form  for  welding  cohesive 
foil. 

Mallet  force  or  percussion,  as  a  means  of  welding  cohesive  gold  and 
condensing  the  siirfaces  of  the  filling,  is  now  considered  by  the  majority 
of  operators  as  the  only  method  by  which  perfect  consolidation  of  a  filling 
can  be  secured.    Fillings  of  cohesive  gold,  made  by  hand-pressure  in  holes 


264 


OPERATIVE    DENTISTEY. 


drilled  in  steel  i)lates,  do  not  weigli  as  mucli  as  those  made  in  the  same 
plates  witli  mallet  forcej  which  jjroves  conclusively  that  more  gold  can  be 


-  ESS 


Fig.  383. 


Varney  pluggers. 

Fig.  384. 
1  a  ll 


Fig.  385. 


Webb  pluggers. 

packed  into  a  cavity,  and  also  more  perfectly  consolidated,  by  the  use  of 

the  mallet  than  by  hand-pressure  alone. 

The  mallet  was  first  introduced  as  a  means  of  i)acking  gold- foil  about 
the  year  1838,  by  Dr.  E.  Merrit,  of  Pittsburg, 
Pa.,  who  used  a  hand  mallet  for  condensing  the 
surface  of  fillings  which  had  been  introduced 
by  hand-pressure.  Earlier  mention  was  made 
of  this  instrument  for  consolidating  gold  by 
Koecker  in  his  '^  Principles  of  Dental  Sur- 
gery," published  in  1826. 

Mallet  force,  however,  was  not  much  used 
until  the  introduction  of  cohesive  foil.  The 
earlier  operators  with  this  form  of  gold  soon 
discovered  that  in  order  to  obtain  perfect  union 
of  the  surfaces  percussion  with  the  mallet  was 
superior  to  hand-pressure.  Various  forms  of 
hand-mallets  were  then  introduced,  made  of 
wood,  ivory,  and  metals,  weighing  from  one- 
half  ounce  to  two  ounces.     The  metal  mallets 

were  made  of  soft  steel,  or  of  lead,  block-tin,  and  various  alloys  encased  in 

metal  or  wood  rims.    The  steel  mallet^  Fig.  385,  seems  to  be  in  the  greatest 

favor  at  the  present  time. 


TREATMENT    OF    CARIES    BY    OBTURATION,    OR    FILLING.  265 


Chappell  pluggers. 

Fig.  388. 


Royce  plugger-points. 


266 


OPERATIVE    DENTISTRY. 


Fig. 


jiiiaiKii 

■  WtmMM 


With  tlie  introduction  of  heavy  gold-foils  came  the  use  of  heavy  mal- 
lets, weighing  from  three  to  four  ounces  or  more.  It  was  thought  by 
those  using  these  extremely  heavy  foils  that  heavy  mallets 
were  necessary  in  order  to  weld  the  surfaces  of  the  foil. 
The  extremes  in  heavy  foil  were  soon  found  to  be  unde- 
sirable, except  for  finishing  fillings,  and  with  the  decadence 
in  the  use  of  these  foils  the  heavy  mallet  ceased  to  find 
advocates. 

Before  the  discovery  that  rubber  sheeting  or  dam  could 
be  so  utilized  as  to  exclude  the  moisture  from  a  cavity 
during  the  operation  of  filling  a  tooth  with  gold  the  oper- 
ator was  obliged  to  employ  one  hand  in  holding  the  nai^kin, 
while  the  other  was  used  to  introduce  the  gold  and  consoli- 
date it.  This  made  it  necessary  to  have  an  assistant  to  do 
the  malleting.  For  various  reasons,  however,  suitable  assist- 
ance could  not  always  be  obtained ;  consequently  inventive 
genius  was  called  into  activity,  and  several  ingenious  auto- 
matic mallets  were  devised,  in  which  by  the  use  of  a  sirring 
a  ]3ercussioii  stroke  is  delivered  upon  the  plugger,  similar  to 
the  stroke  of  the  hand-mallet. 

The  Snow  &  Lewis,  the  Foote,  the  Salmon,  and  the 
Abbott  have  found  the  greatest  favor  with  the  profession. 
Fig.  389  shows  the  Snow  &  Lewis  instrument  of  the  latest 
pattern.  In  using  this  instrument  pressure  is  made  upon 
the  point  of  the  plugger,  as  in  packing  gold  by  hand-pressure  ; 
this  liberates  the  spring,  and  the  plunger  in  the  upper  end  of 
the  instrument  is  thrown  forward  with  considerable  force,  the 
impact  being  expended  upon  the  gold  beneath  the  point  of 
the  plugger.  The  force  of  the  stroke  can  be  regulated  to 
almost  any  degree  to  suit  the  desire  of  the  operator. 

The  Abbott  instrument  (Fig.  390)  has  a  socket  at  each 
end  of  the  handle  or  hand-piece, — one  gives  the  ordinary 
forward  stroke  and  the  other  a  backward  stroke.  The  latter 
was  devised  to  carry  especially  formed  plugger-points  (Fig. 
391)  for  condensing  gold  upon  the  distal  surfaces  of  bicuspids 
and  molars. 

The  Bonwill  electro-magnetic  mallet  (Fig.  392)  is  by  far 
the  most  perfect  mechanical  mallet  that  has  been  invented 
for  condensing  cohesive  gold-foil. 

The  strokes  of  this  mallet  are  delivered  with  great  rapidity 
and  regularity,  and  with  such  force  that  the  gold  can  be  most  perfectly  con- 
densed. Its  essential  parts  are  a  horseshoe  magnet  with  a  hinged  armature 
and  an  automatic  interrupter,  held  in  a  framework  or  handle  to  support 
the  plugger-point.  The  electric  current  may  be  supplied  by  a  Bunsen  or 
Partz  battery,  a  storage  battery,  or  the  controlled  current  from  a  dynamo. 
The  novice  will  at  first  find  some  difficulty  in  using  this  instrument 
with  satisfaction  to  himself  and  his  patient,  but  with  a  little  experience 
he  will  soon  learn  to  control  it  and  to  appreciate  its  merits. 


Snow  &  Lewis 

automatic 

plugger. 


TEEATMENT   OF   CAEIES   BY   OBTUKATION   OR   FILLING. 
Fig.  390. 


267 


Abbott  automatic  mallet  (reduced). 


1 


n\ 


f^    ^^ 


c;^^<^=^ 


Plugger-points  for  Abbott's  automatic  mallet. 


Fig.  392. 


Fig.  393. 


Bonwill  electro-magnetic  mallet  (reduced). 


Bonwill  mechanical  mallet. 


268  OPERATIVE   DENTISTRY. 

The  Bonwill  mechanical  mallet  (Fig.  393)  was  devised  as  an  attachment 
to  the  dental  engine,  to  be  used  as  a  substitute  for  the  electro -magnetic 
mallet.  Its  essential  parts  are  a  small  revolving  wheel,  having  a  lug  upon 
its  periphery,  which  strikes  the  plunger  and  delivers  a  blow  upon  the 
upper  end  of  the  plugging  instrument.  The  force  of  the  stroke  is  under 
perfect  control,  and  the  number  of  strokes  per  second  may  \)e  increased 
from  five  to  twenty,  according  to  the  speed  at  which  the  engine  is  run. 

Crystal  or  Sponge  Gold. — This  form  of  gold  is  made  by  two  pro- 
cesses, one  being  chemical,  the  other  electrolytic.  It  was  first  introduced 
to  American  dentists  by  the  late  Dr.  Watts  in  1853,  under  the  name  of 
sponge  gold.  It  has  been  greatly  modified  and  improved  since  that  time, 
and  now  bears  the  name  of  crystal  gold,  and  is  one  of  the  very  best  prepa- 
rations of  cohesive  gold. 

There  are  several  ways  of  making  this  form  of  gold,  but  they  are  all 
embraced  in  three  general  methods, — viz.,  first,  hy  precipitation ;  secondly, 
hy  combining  a  certain  quantity  of  mercm-y  with  the  precipitate  to  obtain  a  defi- 
nite crystallization  ;  and  thirdly,  by  electrolysis.  Only  pure  metal  can  be  used 
in  the  manufacture  of  this  form  of  gold. 

In  the j^rs^  method  gold  is  added  to  nitro-muriatic  acid  until  a  saturated 
solution  is  obtained.  It  is  then  precipitated  by  the  addition  of  sulphate 
of  iron  or  oxalic  acid,  the  precipitant  being  added  slowly  so  as  to  obtain  a 
crystalline  or  fibrous  form  in  the  deposit.  The  precipitate  is  then  care- 
fully washed  and  slowly  heated  to  nearly  a  cherry-red  heat.  After  cooling 
it  is  ready  for  nse. 

The  second  method  requires  the  combining  of  a  definite  quantity  of  pure 
mercury  with  the  precipitate,  and  after  allowing  it  to  stand  for  a  short 
time  it  is  subjected  to  a  mild  heat,  the  mercury  abstracted  by  treating  the 
precipitate  with  dilute  nitric  acid,  and  washing  it  to  remove  the  nitrate  of 
mercury.  It  is  then  placed  in  a  muffle  and  heated  to  a  bright-red  heat, 
after  which  it  is  ready  for  use  as  a  filling-material. 

By  these  methods  of  manufacture  there  always  remained  an  objection- 
able feature  in  the  presence  within  the  spongy  mass  of  traces  of  nitric 
acid,  which  it  was  difficult  or  impossible  to  get  rid  of. 

Since  the  adoption  of  electrolysis  in  the  place  of  the  above  methods  of 
chemical  precipitation  this  objectionable  feature  no  longer  exists. 

By  this  third  method  a  certain  amount  of  pure  gold  is  dissolved  in  acids, 
the  solution  is  then  placed  in  a  suitable  glass  vessel  and  plates  of  pure 
gold  suspended  in  it.  Then  by  means  of  an  electric  current  the  solution 
is  decomposed  and  the  gold  deposited  in  beautiful  feathery  crystals. 

As  fast  as  the  solution  loses  its  gold  by  the  deposition  of  the  crystals 
it  is  resupplied  by  the  plates  suspended  in  it.  The  deposited  gold  is  then 
removed  and  washed  to  free  it  from  any  trace  of  the  acids  which  held  it  in 
solution,  and  it  is  ready  for  use. 

Gold  prepared  by  this  process  manifests  great  cohesive  properties  and 
is  generally  used  in  large  contouring  operations.  Fillings  made  with  this 
gold  are  as  beautiful  and  as  serviceable  as  any  made  with  cohesive  foil. 
The  secret  of  success  in  the  use  of  crystal  gold  is  to  introduce  it  into  the 
cavity  in  small  pieces,  and  to  thoroughly  condense  each  piece  before  add- 


TREATMENT    OF    CARIES    BY    OBTURATION,    OR    FILLING.  269 

ing  another.    Failures  usually  result  from  attempts  to  introduce  large  pieces, 
whicli  clog  under  the  plugger,  or  to  imperfect  condensation  of  the  gold. 

Gold  of  this  variety  is  sold  in  the  form  of  bricks  containing  one-eighth 
of  an  ounce  each.  It  is  prepared  for  the  cavity  either  by  tearing  it  into 
small  irregular  pieces  or  by  cutting  it  into  small  cubes  with  a  sharp  razor. 
Scissors  should  never  be  used  for  cutting  this  form  of  gold,  as  it  condenses 
the  edges  which  are  cut  and  renders  them  stiff  and  difficult  to  work.  Its 
working  qualities  are  preserved  by  excluding  it  as  much  as  possible  from 
the  atmosphere,  and  when  used  it  should  be  well  annealed.  When  freshly 
made  it  is  sufficiently  cohesive  for  general  use  without  annealing.  Many 
operators  rely  upon  it  for  starting  and  finishing  all  fillings,  but  there  is  no 
form  of  gold  that  is  so  well  adapted  for  starting  fillings  in  shallow  and 
irregular  superficial  cavities  as  this. 

Crystal  Mat  or  Solila  Gold. — Several  other  forms  of  crystal  gold 
have  from  time  to  time  been  introduced  to  the  profession.  That  known 
as  crystal  mat  or  solila  gold  has  found  favor  with  some  operators.  It  is 
manufactured  by  De  Trey,  and  was  first  introduced  in  the  United  States 
in  1897.  It  is  sold  in  the  form  of  thick  sheets  or  mats,  and  differs  from 
sponge  gold  in  that  it  is  more  compact  in  form  and  the  crystals  are  smaller 
and  matted  together.  It  does  not  work  as  readily  as  the  sponge  gold,  and 
breaks  and  crumbles  under  the  plugger  to  a  much  greater  degree,  causing 
considerable  waste.  It  possesses  no  good  features  which  are  not  possessed 
by  Watts'  s  crystal  gold  except  that  it  is  more  plastic.  Deep  undercuts 
and  retaining-pits  are  not  necessary  for  the  retention  of  this  gold.  Cavities 
having  three  or  four  walls  may  be  prepared  as  for  plastics.  Hand-press- 
ure and  broad- faced  pluggers  are  best  for  working  this  gold.  On  account 
of  its  tendency  to  break  and  crumble  under  the  j)lugger  it  is  difficult 
to  use  it  for  contour  work  where  a  matrix  cannot  be  used.  In  simple 
cavities  and  in  approximal  cavities  where  the  matrix  is  admissible  it 
makes  a  beautiful  and  serviceable  filling  and  with  little  waste  of  material. 

In  annealing  this  gold,  it  should  never  be  heated  to  a  cherry-red ; 
annealing  just  short  of  this  point  gives  the  best  results. 

In  starting  the  filling  a  large  piece  should  be  used,  large  enough  to 
cover  the  bottom  of  the  cavity,  and  this  thoroughly  condensed  against  the 
walls.  Smaller  pieces  should  be  used  in  building  the  balance  of  the  filling, 
care  being  taken  to  thoroughly  condense  each  piece  before  another  is  added, 

Small  instruments  should  be-  used  for  condensing  the  filling  against 
the  enamel  margins,  as  perfect  adaptations  cannot  be  secured  with  large 
pluggers. 

Operators  who  are  accustomed  to  using  non-cohesive  foil  will  experience 
the  least  trouble  in  its  manipulation,  as  the  methods  used  in  its  introduc- 
tion and  consolidation  are  quite  similar.  The  ordinary  methods  should  be 
followed  in  finishing  and  polishing  the  filling. 

Moss  fibre  gold,  manufactured  by  the  S.  S.  White  Dental  Manu^ 
facturing  Company  is  the  latest  (1898)  form  of  sponge  gold  that  has  been 
introduced  to  the  profession.  It  is  an  exceedingly  soft,  tough,  cohesive 
gold,  and  possesses  these  qualities  in  a  much  larger  degree,  perhaps,  than 
any  other  sponge  gold  upon  the  market.     It  is  easily  adapted  to  the  walls 


270  OPERATIVE    DENTISTRY. 

of  the  cavity,  permits  of  extensive  contouring,  and  when  condensed  pre- 
sents a  hard,  tongh  surface,  and  takes  a  beautiful  finish. 

Deej)  undercuts  or  retaining-pits  are  not  necessai-y  in  order  to  start  a 

filling.     The  floor  of  the  cavity  should  be  as  nearly  flat  as  is  possible,  and 

the  retentive  shape  given  to  it  should  be  the  same  as  for  non-cohesive  foil. 

Eound-faced  pluggers  with  fine,   shallow  serrations,   like  the  Eoyce 

instruments,  are  the  best  for  packing  and  condensing  this  form  of  gold. 

Small  pieces  of  gold  only  should  be  used.  Large  pieces  cause  bridging 
and  result  in  a  porous  filling. 

In  introducing  the  gold,  each  piece  should  be  placed  in  the  position 
required,  and  first  ^'jjatted"  with  the  plugger  until  evenly  condensed,  and 
then  thoroughly  condensed  with  hand-pressure  or  the  mallet  before  another 
piece  is  added.     Heavy  malleting  is  not  needed  to  condense  this  gold. 

Care  must  be  exercised  in  annealing  "  moss  fibre  gold"  not  to  overheat 
it.  Under  no  circumstances  should  it  be  brought  into  contact  with  the 
flame  of  the  lamp.  Slightly  warming  the  gold  over  a  lamp  upon  a  sheet 
of  mica  is  all  that  is  required.  Overheating  makes  it  hard  and  gives  it 
a  tendency  to  "ball"  under  the  plugger.  Extensive  contour  operations 
can  be  made  with  it  more  easily  than  with  Watts's  crystal  gold. 

Gold-and-Platinum  Foil. — This  form  of  foil  was  first  suggested  by 
Moffet,  of  Boston,  and  is  a  combination  of  gold  and  platinum.  It  is  made  by 
'^  sweating"  together  an  ingot  of  gold  and  one  of  platinum  and  then  rolling 
to  any  thickness  desired.  ]N"o.  20  and  No.  30  are  the  thicknesses  generally 
made.  It  has  the  appearance  of  gold-foil  before  it  is  introduced  into  the 
cavity,  but  the  condensing  process  brings  out  the  color  of  the  platinum. 

This  form  of  gold  was  in  great  favor  a  few  years  ago  for  restoring  the 
morsal  edges  and  labial  surfaces  of  incisor  and  cuspid  teeth,  and  for  fin- 
ishing fillings  upon  the  morsal  surfaces  of  bicuspids  and  molars.  The 
advantages  claimed  for  it  over  gold  alone  are  its  better,  or,  rather,  less 
conspicuous  color  and  its  greater  hardness. 

It  is  prepared  for  use  by  cutting  the  foil  into  narrow  strips  or  ribbons, 
and  after  being  freshly  annealed  it  is  welded  to  the  gold  filling  in  the 
same  manner  as  heavy  gold-foil.  Especial  'care  should  be  exercised,  how- 
ever, in  its  introduction  to  see  that  each  layer  is  thoroughly  welded  over 
its  whole  surface  before  another  piece  is  added.  Mallet  force  is  superior  to 
hand-pressure  in  its  condensation,  and  round-faced  foot-pluggers  with  fine 
serrations  give  the  best  results. 

On  account  of  the  stiffness  of  this  form  of  foil  it  should  be  used  only 
for  the  purposes  just  enumerated.  To  attempt  to  use  it  to  fill  the  body  of 
a  cavity  would  only  end  in  a  disastrous  failure,  either  by  fracturing  the 
walls  of  the  cavity  from  the  force  necessary  to  condense  it  or  from  faulty 
adaptation  to  the  walls  and  margins  inviting  secondary  decay. 

Annealing  Process. — All  metals  become  more  or  less  stiff  and  hard 
by  the  process  of  hammering  and  rolling.  Gold-foil  which  has  been  made 
by  either  of  these  processes  has,  when  it  comes  from  the  beater' s-skins  or 
the  rollers,  lost  its  softness  and  ductility.  To  restore  these  qualities  it 
becomes  necessary  to  heat  it.  This  process  is  termed  annealing.  The 
amount  of  heat  used,  and  the  length  of  time  to  which  the  foil  is  subjected 


TREATMENT    OP    CARIES    BY    OBTURATION,    OR    FILLING. 


271 


to  it,  will  depend  upon  the  degree  of  softness  or  of  cohesiveness  desired. 
All  i^ure  foil  is  rendered  cohesive  by  annealing,  but  certain  non-cohesive 
foils— those  in  which  it  is  claimed  iron  has  been  used  as  an  alloy — may  be 
rendered  soft  and  ductile  by  annealing  without  rendering  them  cohesive. 
Freshly  made  cohesive  foil  does  not  need  to  be  reannealed  except  for  con- 
tour work.  Exposure  to  the  atmosphere,  however,  soon  renders  it  non- 
cohesive  and  makes  reannealing  necessary  if  contouring  is  contemplated. 

The  alcohol  flame  or  the  gas  flame  from  a  Buusen  burner  are  generally 
used  for  the  purpose  of  annealing.  Some  operators  hold  the  piece  of  foil 
in  the  flame,  others  hold  it  just  above,  thus  heating  it  to  the  desired  de- 
gree. Others  use  annealing  trays  made  of  mica,  Eussia  iron,  or  platiuum, 
which  are  held  over  the  flame  of  the  alcohol  lamx^  or  gas-jet.  The  latter 
method  is  the  best,  for  the  reason  that  it  excludes  the  possibility  of  dele- 
terious substances  like  carbon,  sulphur,  or  jDhosphorus  being  deposited 
upon  the  gold  from  the  combustion  of  the  lamx^-wick,  or  jDarticles  of  sul- 
phur or  phosphorus  which  have  been  dropped  uj^on  the  wick  in  igniting 
it  with  a  match,  or  in  the  case  of  the  Bunsen  burner,  from  imperfect  com- 
bustion of  the  gas,  which  might  deposit  carbon  or  sulphur. 

Fig.  394. 


Custer  electric  gold  annealer. 
Fig.  395. 


Kerr  electric  gold  annealer. 

Electric  Annealing  Tray. — The  neatest  and  also  the  most  satisfactory 
devices  for  annealing  gold  are  the  electric  annealing  tray  of  Custer,  shown 
in  Fig.  394,  and  that  of  Kerr,  shown  in  Fig.  395. 

By  these  devices  any  degree  of  heat  that  may  be  desired  can  be  obtained, 
and  with  a  uniformity  not  possible  with  any  other  device  or  method. 


CHAPTEE    XVIII. 


CONSIDERATIONS   IN   FILLING   SPECIAL  CS-ASSES  OF   CAVITIES. 


I.  Simple  Cavities  upon  Exposed  Surfaces. — This  class  of  cavities 
presents  the  most  simple  forms  of  fillings  in  the  whole  range  of  oi^erative 
procedures  upon  the  teeth. 

Cavities  which  are  situated,  upon  the  lahial  surfaces  of 
Fig.  396.  incisors  and  cuspids,  especially  when  they  have  involved  the 
cervix  and  extended  beneath  the  margin  o£  the  gum,  often 
present  serious  difficulties  to  the  introduction  of  gold,  which 
test  the  ingenuity,  skill,  and  patience  of  the  operator,  as  well 
as  the  fortitude  of  the  i^atient. 

One  of  the  most  formidable  difficulties  to  be  overcome  is 
the  adjustment  of  the  rubber  dam  to  those  cases  in  which  the 
cavity  extends  beneath  the  free  margin  of  the  gum.  This 
may  sometimes  be  accomplished  by  passing  a  ligature  around 
the  cervix  of  the  tooth  and  forcibly  carrying  it  towards  the 
apex,  until  the  dam  passes  beyond  the  border  of  the  cavity, 
or  the  gum  may  be  held  away  by  the  aid  of  the  gum  retractor, 
shown  in  Fig.  396. 

It  is  always  best  to  include  in  the  rubber  dam  not  only 
the  tooth  to  be  operated  upon,  but  at  least  one  u^Don  either 
side  of  it.  The  How  cervix  clamp,  shown  in  Fig.  397,  often 
serves  a  good  j)urpose  in  retaining  the  rubber  dam  in  position, 
as  do  also  the  Libby  clamp  (Fig.  398),  the  Johnson  lever  clamp  (Fig.  399), 
and  the  Dunn  clamp  (Figs.  400  and  401). 


Gum  retractor 
(reduced). 


Fig.  397. 


Fig.  398. 


How  cervix  clamp. 


Libby  clamp, 


It  is  sometimes  necessary  to  slit  the  edge  of  the  gum  above  the  cavity 
in  order  to  gain  a  clear  view  of  the  gingival  margin  and  to  permit  the 
rubber  dam  to  go  above  it. 

Cavities  occurring  in  the  labial  surfaces  of  the  incisors  and  cuspids  are 
generally  located  either  at  the  cervix  or  in  the  frequent  imperfections  of 
272 


CONSIDERATIONS    IN    FILLING   SPECIAL    CLASSES    OF    CAVITIES.       273 


Fig.  399. 


the  enamel,  due  to  developmental  defects.  As  a  rule  they  are  shallow,  and 
therefore  need  to  be  given  a  good  retentive  form,  either  by  slightly  en- 
larging the  cavity  at  the  bottom  or  by  forming  small 
retaining-pits  in  the  extremities.  Cohesive  foil  or 
crystal  gold  are  the  best  for  filling  this  class  of  cavi- 
ties. The  filling  should  be  started  in  one  of  the  ex- 
tremities, care  being  taken  that  the  first  piece  of  gold 
is  securely  anchored  and  the  balance  of  the  filling 
built  upon  this.  Many  operators  finish  such  fillings 
with  platinum-gold  foil^  as  the  color  is  less  conspicuous 
than  pure  gold.  Figs.  402  and  403  show  the  location 
of  fillings  of  this  class. 

Cavities  occurring  upon  the  lingual  surface  of  the 
incisors  are  generally  confined  to  the  laterals,  and  are 
the  result  of  developmental  defects,  as  shown  in  the 
imperfect  closure  of  the  pit  or  fissure  at  the  base  of 
the  cingulum.  These  cavities  are  usually  small,  and 
are  readily  filled  with  a  narrow  ribbon  of  non-cohesive 


foil  and  finished  with  cohesive ;  or  the  entire  cavity 


Johnson  lever  clamp. 


may  be  filled  with  a  narrow  ribbon  of  cohesive  foil, 
in  Fig.  404. 


Such  a  filling  is  shown 


Fig.  400. 


Fig.  402. 


Fig.  403. 


Fig.  404. 


Caries  rarely  attacks  the  morsal  edge  of  the  incisors  and  cuspids,  except 
as  the  result  of  imperfections  in  development,  from  mechanical  abrasion, 
or  from  traumatic  injuries  which  fracture  the  enamel.  Consequently  the 
operation  of  filling  is  usually  confined  to  artificial  cavities,  made  for  the 
purpose  of  protecting  the  morsal  edges  against  the  loss  of  tooth-substance 
from  mechanical  or  chemical  abrasion,  or  for  lengthening  the  teeth  when 
it  is  desired  to  "open  the  bite." 

Cavities  prepared  for  this  purpose  must  have  strong  retentive  form,  as 
fillings  of  this  class  are  constantly  subjected  to  great  stress.     Many  opera- 

18 


274  OPERATIVE    DENTISTRY, 

tors  are  in  tlie  liabit  of  inserting  a  couple  of  "Mack"  screws  in  tlie  arti- 
ficially formed  cavity,  one  near  eacli  extremity,  as  sliown  in  Fig.  405. 
These  add  very  greatly  to  the  retentive  strength  of  the  cavity  and  make 
it  very  difficult  to  dislodge  such  a  filling. 

Care  must  be  exercised  in  setting  the  screws  not  to  encroach  upon  the 
pulp. 

Fig.  406. 
Fig.  405. 


Cohesive  gold  only  should  be  used  for  building  up  these  fillings.  It 
may  be  either  foil  or  crystal  gold,  as  suits  the  fancy  or  the  ability  of  the 
operator  to  manipulate  one  form  of  gold  better  than  another.  In  making 
the  choice  he  should  always  select  that  form  of  gold  with  which  he  is  con- 
fident the  best  filling  can  be  made.  In  starting  the  filling  it  is  advisable 
to  begin  at  one  extremity  of  the  cavity  by  anchoring  the  gold  in  the  under- 
cut or  retaining- pits,  then  repeat  the  process  in  the  other  extremity,  and 
afterwards  connect  them  together  by  a  narrow  ribbon  laid  upon  the  bottom 
of  the  cavity  and  folded  back  and  forth,  each  fold  being  thoroughly  con- 
densed upon  the  preceding  one,  care  being  taken  to  accurately  fill  the 
undercut  before  the  building  process  is  begun. 

Fillings  in  these  locations  must  be  thoroughly  condensed  with  the 
mallet  in  order  that  they  may  obtain  the  greatest  hardness  possible  to  pure 
gold,  as  they  are  subjected  to  severe  wear,  which  might  result  in  abraded 
edges  and  flaking  of  the  layers  of  gold.  Fig.  406  shows  the  completed 
oi)eration. 

Platinum-gold  in  narrow  ribbons  of  'No.  20  or  No.  30  is  preferred  by 
some  operators  for  all  of  that  part  of  the  filling  which  extends  beyond  the 
walls  of  the  retaining  cavity.  The  Bonwill  electric  mallet  or  the  engine 
mallet  are  invaluable  for  packing  the  gold  in  these  cases. 

Cavities  occurring  in  the  fissures  and  sulci  of  the  morsal  surface  of  the 
Mcusjnds  and  molars  are  the  most  accessible,  and  from  their  location  offer 
the  least  difficulty  to  the  introduction  of  gold  fillings.  Such  cavities,  if 
prepared  with  perpendicular  or  slightly  undercut  walls,  need  no  other 
retentive  shaping  to  insure  firm  anchorage  of  the  filling.  These  cavities 
can  be  most  rapidly  and  substantially  filled  with  non- cohesive  foil ;  in  fact, 
this  is  one  of  the  most  favorable  locations  for  the  use  of  non-cohesive  foil. 
The  gold  can  be  introduced  in  the  form  of  narrow  ribbons,  small  cylinders, 
or  small  spindle-shaped  pellets. 

In  introducing  ribbons,  one  end  should  be  grasped  with  the  foil-pliers 
and  carried  to  the  bottom  of  the  cavity,  at  that  point  which  is  farthest  from 
the  operator^ — this  is  a  safe  rule  to  follow  in  starting  all  classes  of  fillings, — 
and  secured  in  place  by  a  point  held  in  the  left  hand,  while  with  the  pliers 
the  ribbon  is  folded  upon  itself  and  carried  again  to  the  bottom  of  the  cav- 
ity, and  the  fold  packed  firmly  against  its  walls  with  a  wedge-shaped  or  a 
foot-shaped  plugger,  but  permitting  the  outer  end  of  the  ribbon  to  projed 


CONSIDERATIONS   IN   FILLING   SPECIAL   CLASSES   OF   CAVITIES.      275 

a  little  beyond  the  walls  of  the  cavity.  A  second  ribbon  is  now  introduced 
in  the  same  manner  and  packed  against  the  wall  nearest  the  operator.  A 
third  ribbon  is  introduced  in  the  same  manner  and  packed  against  the  two 
opposite  uncovered  walls,  and  the  operation  completed  by  driving  ribbons 
of  cohesive  foil  into  the  filling,  and  finishing  with  heavy  foil.    Or,  cylin- 

FiG.  407. 


ders  may  be  introduced  instead  of  ribbons,  placing  them  on  end  in  the  cav- 
ity and  packing  them  against  the  walls,  finishing  in  the  centre  with  a  hard- 
rolled  pellet,  and  then  thoroughly  condensing  the  projecting  ends  of  the 
cylinders.  Or  the  spindle-shaped  pellets  may  be  used,  the  tip  of  one  end 
of  which  should  be  annealed  by  passing  it  in  the  flame  of  the  spirit-lamp, 
and  the  annealed  ends  allowed  to  project  slightly  beyond  the  walls  of  the 
cavity.  These  are  packed  against  the  walls  of  the  cavity  after  the  same 
manner  as  cylinders,  the  centre  finally  receiving  a  pellet  of  cohesive  gold. 
The  ends  of  the  pellets  which  project  beyond  the  walls  of  the  cavity  are 
then  condensed,  and  the  surface  finished  with  mats  of  cohesive  foil,  which 
welds  without  flaw  to  the  surface  formed  by  the  annealed  ends  of  the  pellets. 
By  this  method  the  danger  of  the  surface  of  the  filling  scaling  off  is  obviated. 
Scaling  off  of  the  surface  of  the  filling  often  occurs  when  the  union  of  the 
cohesive  gold  with  the  balance  of  the  filling  is  only  mechanical.  All  fillings 
upon  the  morsal  surfaces  of  the  teeth  should  be  made  as  hard  as  possible 
by  thorough  but  judicious  malleting.  Pig.  407  shows  the  finished  fillings. 
In  cavities  of  larger  size  and  depth,  requiring  the  cutting  away  of  the 
triangular  ridge,  and  in  those  involving  more  considerable  portions  of  the 
morsal  surface  of  the  molars,  but  in  which  the  walls  are  perpendicular  and 
strong  (Figs.  408  and  409),  cylinders  will  be  found  to  offer  the  most  rapid 
and  efficient  means  of  introducing  the  filling.     These  should  be  packed 

Fig.  408.  Fig.  409. 


solidly  against  the  walls  in  all  directions,  and  the  central  portion  filled  by 
inserting  cylinders,  one  after  another,  as  long  as  space  can  be  made  for 
one  with  heavy  wedge-shaped  pluggers.  The  protruding  ends  should  next 
be  thoroughly  condensed,  and  the  surfaces  finished  in  the  manner  described 
above. 

In  broad,  shallow  cavities,  or  those  of  uneven  depth,  cohesive  foil  is 
better  adapted  for  the  purpose  than  the  non-cohesive.  Such  cavities  need 
to  be  shaped  with  undercuts  at  opposite  points,  or  retaining-pits  or  grooves 
at  the  bottom  of  the  cavity,  and  so  placed  as  to  offer  the  greatest  resistance 
to  mechanical  dislodgement. 


276  OPERATIVE  PENTISTRY, 

Tn  the  introduction  of  cohesive  foil,  the  retain ing-pits  or  grooves  are 
filled  first,  and  the  subsequent  layers  of  gold  welded  to  them  and  to  each 
other.  Cavities  of  uneven  depth  may  be  filled  in  the  deepest  portion  with 
pellets  of  non-cohesive  foil  which  have  been  rendered  semi-cohesive  at  one 
end  by  annealing  in  the  spirit-lamp,  and  the  balance  with  ribbons,  pellets, 
or  mats  of  cohesive  foil.  In  all  deep  cavities — those  which  approach  very 
near  to  the  pulp — this  organ  should  be  protected  from  thermal  shock  by 
the  interposition  of  a  layer  of  oxyphosphate  cement  or  other  suitable  non- 
conducting medium. 

Cavities  in  the  buccal  surfaces  of  the  bicuspids  and  molars  are  a  little 
more  inaccessible  to  operation  than  those  of  the  class  just  described,  and 
as  a  majority  of  these  cavities  are  at  the  cervical  border,  difficulty  is  often 
experienced  in  adjusting  the  rubber  dam  so  as  to  expose  the  cervical  mar- 
gin of  the  cavity.  The  exclusion  of  moisture  renders  them  but  little  more 
difficult  to  fill  than  those  upon  the  morsal  surfaces,  except  when  located  in 
the  third  molar,  or  when  the  patient's  mouth  is  small,  or  the  lips  and 
cheeks  are  non-elastic. 

In  deciding  which  form  of  gold  shall  be  used  in  each  individual  case, 
the  size  and  the  depth  of  the  cavity  must  be  taken  into  consideration. 
Deep  cavities  are  best  filled  with  non-cohesive  foil  made  into  ribbons, 
cylinders,  or  pellets,  and  the  surface  finished  with  cohesive  foil.  Shallow 
cavities  are  always  more  easily  filled  with  cohesive  foil  or  crystal  gold  than 
with  the  non-cohesive.  Watts' s  crystal  gold  is  most  admirable  for  filling 
such  cavities,  as  it  requires  but  slight  retentive  shaping  to  obtain  firm 
anchorage,  and  it  does  not  possess  the  same  tendency  to  "ball"  or  curl  up 
at  the  edges  and  rock  in  the  cavity  as  does  cohesive  foil. 

Especial  attention  should  be  given  to  the  cervical  margin  in  all  those 
cavities  which  approach  the  gum  line  or  extend  beneath  it.  Non-cohesive 
foil  will  be  more  likely  to  insure  a  perfect  sealing  of  the  cavity  at  this  point 
than  cohesive  foil  by  reason  of  its  more  ready  adaptability.  It  is  therefore 
advisable  to  place  a  thick  mat  or  a  large  pellet  of  non-cohesive  foil  at  the 
cervical  margin,  and  make  the  balance  of  the  filling  with  cohesive  gold. 
Fig.  410  represents  the  finished  filling. 

Cavities  located  upon  the  lingual  surfaces  of  the  bicuspids  and  molars 
are  quite  rare  except  in  the  lingual  fissures  of  the  superior  molars.     Occa- 

FiG.  410. 


Pilling  in  buccal  surface  of  a 
bicuspid. 


sionally,  however,  they  are  found  in  teeth  of  defective  development,  and 
at  the  cervix  and  upon  the  roots  of  the  teeth  as  a  result  of  gingival  reces- 
sion. Cavities  of  this  class  occurring  in  the  inferior  bicuspids  and  molars 
offer  considerable  difficulty  to  the  introduction  of  gold  fillings,  and  for  this 


CONSIDERATIONS   IN   FILLING   SPECIAL   CLASSES   OF   CAVITIES.      277 

reason  plastics  are  more  often  used  in  these  locations  than  any  other  filling- 
material.  When  they  occur  in  the  superior  molars,  gold  can  be  more  read- 
ily introduced,  though  by  reason  of  the  limited  accessibility  of  the  cavity 
it  becomes  necessary  to  use  hand-pressure  for  the  greater  part,  if  not  the 
whole,  of  the  operation.  The  same  method  of  filling  as  described  for  cavi- 
ties upon  the  buccal  surfaces  should  be  pursued  in  filling  the  accessible 
cavities  of  this  class. 

II.  Simple  Approximal  Cavities. — This  class  of  cavities  are  those 
which  are  found  upon  the  approximal  surfaces  of  all  the  teeth,  but  which 
do  not  involve  any  other  surface,  and  are  bounded  by  a  continuous  and 
unbroken  wall. 

Cavities  of  this  class  occurring  upon  the  approximal  surfaces  of  the 
incisors  and  cuspids  generally  require  preliminary  treatment  by  temporary 
separation,  either  by  tape  and  wedges,  or  the  more  rapid  method  with  the 
Perry  or  other  screw  separator.  If  the  cavity  is  small  and  well  within 
the  labio-  and  linguo-mesial  or  distal  angles,  the  case  presents  no  difficul- 
ties other  than  those  growing  out  of  its  degree  of  inaccessibility.  Such 
cavities  may  be  two-thirds  filled  with  non-cohesive  foil,  cut  in  narrow  rib- 
bons, and  the  balance  with  cohesive  foil.  Curved  pluggers  are  necessary 
in  filling  these  cavities,  on  account  of  the  proximity  of  the  adjoining 
teeth. 

In  cavities  which  involve  a  considerable  portion  of  the  approximal  sur- 
face, retention  is  secured  at  the  cervical  border  by  a  groove  at  the  base  of 
the  cavity,  combined  with  a  retaining-pit  at  the  extremities,  and  by  a 
shallow  undercut  at  the  morsal  border.  Grooving  the  labial  or  lingual 
walls  for  the  purpose  of  retention  is  to  be  deprecated,  as  it  tends  to 
weaken  them,  and  increases  the  liability  to  fracture  and  dislodgement  of 
the  filling. 

The  dentist  who  possesses  the  spirit  of  the  true  artist  will  at  all  times 
endeavor  to  conceal  the  gold  as  much  as  possible  when  he  is  called  upon 
to  place  it  in  the  anterior  teeth.  Consequently  he  will,  whenever  possible, 
conserve  the  labial  wall  of  these  teeth.  The  filling  should  be  started  in 
one  of  the  retaining-pits  at  the  extremity  of  the  groove  made  at 
the  cervical  border,  then  the  pit  in  the  opposite  extremity  should  Fig.  412. 
be  filled,  and  both  united  by  attaching  a  ribbon  of  gold  from 
one  to  the  other,  and  malleting  it  into  the  retaining  groove. 
This  gives  a  firm  foundation  upon  which  to  build  the  filling 
and  secures  thorough  adaptation  of  the  gold  to  the  cervical  wall. 
The  balance  of  the  filling  is  then  completed  after  the  manner 
already  described  in  filling  simple  cavities.  Cohesive  gold, 
either  foil  or  crystal  gold,  is  best  adapted  for  fillings  of  this  character. 
Fig.  412  shows  the  completed  filling. 

Simple  api^roximal  cavities  in  the  mesial  or  distal  surfaces  of  the  bicuspids 
and  molars  offer  considerably  more  difficulty  in  filling  than  similar  cavities 
in  the  anterior  teeth,  by  reason  of  their  less  accessible  position.  Tempo- 
rary separation  is  always  necessary  in  those  cases  presenting  a  normal  ap- 
proximation of  the  teeth.  When  the  cavities  are  large  it  often  becomes 
necessary,  in  order  to  gain  a  clear  view  of  all  parts  of  the  cavity,  to  con- 


278  OPERATIVE    DENTISTRY. 

vert  a  simple  into  a  compound  one  5  or  this  procedure  may  be  necessary 
on  account  of  the  extension  of  the  disease  in  directions  which  undermine 
the  enamel,  making  it  too  frail  to  bear  the  stress  of  mastication. 

Simple  cavities  in  these  locations  may  be  filled  after  the  manner  de- 
scribed for  filling  similar  cavities  in  the  anterior  teeth,  with  the  excei)tion 
that  by  reason  of  their  greater  degree  of  inaccessibility  hand-pressure 
becomes  necessary  in  packing  the  gold  for  the  greater  i^art  of  the  opera- 
tion. Non-cohesive  foil  can  be  used  to  advantage  in  this  class  of  fillings 
if  used  in  narrow  ribbons,  or  loosely  rolled  cylinders  or  pellets,  and  the 
surface  finished  with  cohesive  foil.  Some  operators  prefer  cohesive  gold 
throughout  the  operation.  In  such  case  the  filling  is  started  in  small 
undercuts  or  pits  made  at  the  cervical  border.     The  mallet  is  sometimes 

Fig.  414. 
Fig.  413. 


tiSed  for  condensing  the  surface,  but  it  is  less  applicable  to  the  distal  sur- 
faces than  to  the  mesial.  Figs.  413  and  414  represent  medium-sized  fillings 
in  thi  approsimal  surfaces  of  bicuspids  and  molars. 

in.  Compound  Cavities, — Compound  cavities  are  those  which  in- 
volve two  or  more  surfaces  of  the  tooth,  and,  by  reason  of  this,  present  the 
greatest  difficulties  in  the  operation  of  filling. 

Cavities  which  involve  the  mesio-ldbial  and  disto-lahial  surfaces  of  the 
incisors  and  cuspids  are  the  least  difficult  of  the  series  to  fill,  from  the  fact 
that  an  unobstructed  view  can  be  obtained  of  every  part  of  the  cavity  by 
direct  light  and  unaided  vision.  Each  portion  of  the  cavity  should  be  so 
shaped  as  to  give  it  an  iudei^endent  retentive  form.  Cohesive  foil  is  best 
for  filling  this  class  of  cavities,  as  the  welding  property  is  valuable  in 
binding  the  fillings  together,  giving  to  them  a  proper  contour  and  a  more 
highly  finished  surface.  Foil  cut  in  ribbons  and  freshly  annealed  or  crystal 
gold  should  always  be  used  in  this  class  of  cavities.  In  starting  these 
fillings  the  general  rule  of  beginning  all  fillings  at  the  point  farthest  from  the 
operator  holds  good.  When  the  approximal  cavity  is  about  two  thirds  full 
the  filling  in  the  labial  cavity  should  be  started  and  connected  with  the 
approximal  filling,  and  the  whole  then  treated  as  one  filling  ;  in  this  way 
both  fillings  are  bound  solidly  together,  and  dislodgement  is  impossible 
except  by  fracturing  the  tooth. 

As  these  fillings  (Fig.  415)  are  constantly  exposed  to  view,  the  greatest 
pains  should  be  taken  to  give  them  an  artistic  form  and  finish  by  restoring 
the  natural  contour  of  the  tooth,  avoiding  peculiar  marginal  lines,  and  so 
finishing  the  surface  of  the  gold  as  to  make  it  as  little  conspicuous  as 
possible. 

Mesio-lingual  and  disto-Ungual  cavities  in  the  incisors  and  cuspids  may  be 
filled  (Fig.  416)  in  xDrecisely  the  same  manner  as  those  cavities  last  de- 


CONSIDERATIONS    IN    FILLING    SPECIAL   CLASSES    OF    CAVITIES.       279 


scribed,  care  being  taken  that  the  retentive  form  of  each  cavity  is  such  as 
to  secure  independent  anchorage,  and  the  gold  so  prepared  that  its  welding 
property  will  be  at  its  maximum  degree. 

Cavities  involving  the  mesio-morsal   and   disto-morsal  surface  of  the 
incisors  and  cuspids  are  among  the  most  dif&cult  fillings  to  make  substantial 


Fig.  415. 


Fig.  416. 


Fig.  417. 


by  reason  of  their  form  and  exposed  position  to  stress  and  leverage  (Fig. 
417).  The  greatest  care  must  therefore  be  exercised  in  securing  firm  an- 
chorage, and  if  this  cannot  be  done  within  the  formed  cavity,  it  should 
be  extended  in  some  direction  which  will  secure  this  without  unnecessarily 
weakening  the  tooth. 

Figs.  418,  419,  and  420  represent  such  methods  of  extension  for  anchor- 
age. In  teeth  having  a  broad  morsal  edge,  additional  anchorage  may  be 
secured  by  slightly  grooving  the  labial  and  lingual  walls  at  this  point. 

Cohesive  gold  is  best  adapted  to  the  requirements  of  such  a  filling,  and 
used  in  such  form  as  to  preclude  the  possibility  of  the  gold  clogging  under 

Fig.  420. 


Fig.  418. 


Fig.  419. 


(From  Dental  Cosmos.) 

the  instrument,  as  air-spaces  resulting  from  imperfect  consolidation  of  the 
foil  are  an  element  of  weakness  in  the  filling. 

The  filling  should  be  started  at  the  cervical  border  and  built  up  from 
this  point,  keeping  the  surface  of  the  gold  as  nearly  flat  as  possible,  and 
restoring  the  contour  as  the  filling  progresses,  care  being  taken  to  secure 
perfect  adaptation  of  the  gold  to  the  labial  and  lingual  enamel  margins. 
An  electric  or  engine  mallet  greatly  facilitates  the  rapidity  of  the  opera- 
tion, and  insures  more  perfect  consolidation  of  the  gold  than  can  be  obtained 
by  hand-pressure  or  the  hand-mallet  without  the  expenditure  of  an  infinite 
amount  of  time  and  labor.  To  guard  against  bruising  or  flaking  of  the 
morsal  edge  of  the  filling,  thorough  condensation  of  the  gold  must  be 
secured.  Heavy  foil,  No.  20  or  No.  30,  if  each  piece  is  thoroughly  welded 
to  the  surface  of  the  filling  before  another  is  added,  will  make  the  hardest 
surface  obtainable  with  gold. 


280  OPERATIVE   DENTISTRY. 

Cavities  which  involve  hoth  approximal  surfaces  and  the  morsal  edge  of 
the  incisors  and  cuspids — mesio-disto-morscd  cavities — present  the  greatest 
difficulties  from  the  mechanical  stand-point  in  the  whole  range  of  opera- 
tions for  restoring  lost  portions  of  tooth-structure  with  gold,  but  when  the 
operation  is  finished  it  becomes,  by  reason  of  its  form,  one  of  the  most 
secure  fillings  that  it  is  possible  to  make. 

The  filling  may  be  started  at  the  cervical  border  in  the  pits  and  grooves 
made  for  the  purpose  in  either  of  the  approximal  cavities,  preferably  in 
that  one  which  is  farthest  from  the  operator.  Cohesive  gold  only  is  admis- 
sible in  this  class  of  fillings.     The  filling  should  be  built 

"Fir    421 

up  from  the  cervical  border  as  squarely  as  possible  until 
the  morsal  edge  is  reached.  The  same  method  is  then 
employed  in  the  approximal  cavity  nearest  to  the  oper- 
ator, and  when  the  morsal  edge  is  reached  the  fillings  are 
united  by  carrying  the  gold  across  the  morsal  edge,  and 
finally  finished  at  the  approximo-morsal  angle  nearest  to 
the  operator.  Fig.  421  represents  the  completed  filling.  If  the  approxi- 
mal fillings  have  been  securely  anchored,  the  force  applied  upon  their 
morsal  extremities  will  have  no  tendency  to  dislodge  them  during  the 
process  of  building  the  morsal  edge,  but  if  this  j)reliminary  step  has  not 
been  properly  taken,  dislodgement  is  more  than  likely  to  occur  before  the 
operation  is  completed. 

Cavities  involving  the  mesial  and  morsal  surfaces — mesio-morsal — of  the 
bicuspids  and  molars  offer  no  difficulties  which  are  not  readily  overcome. 
The  only  preliminary  necessary  for  the  preparation  and  filling  of  the 
cavity  is  the  obtaining  of  such  an  amount  of  space  by  some  of  the  methods 
of  temporary  separation  as  will  enable  the  operator  to  gain  a  clear  view 
of  the  cavity  in  all  of  its  parts,  and  permit  of  the  original  form 
Fig.  422.  ^f  ^jie  tooth  being  restored  by  the  insertion  of  a  contour  filling, 
as  illustrated  in  Fig.  422. 

Failures  in  this  class  of  fillings  are  pi'one  to  occur  at  the  cer- 
vical border  from  secondary  caries,  and  this  is  often  due  either 
to  imperfect  preparation  of  this  portion  of  the  cavity,  to  bruising 
of  the  enamel  margin  while  condensing  the  gold  against  it,  or  to  imperfect 
adaptation  of  the  gold  to  the  cervical  wall.  The  greatest  care  should 
therefore  be  exercised  in  the  preparation  of  the  cavity  and  the  introduc- 
tion of  the  gold. 

The  cervical  margin  may  be  protected  against  bruising  and  i)erfect 
adaptation  of  the  gold  to  the  tooth  secured  by  introducing  a  non-cohesive 
soft-rolled  cylinder  and  condensing  it  against  the  cerv^ical  border.  Many 
operators  are  in  the  habit  of  filling  the  cervical  third  of  the  cavity  with 
non-cohesive  cylinders  and  the  balance  with  cohesive  foil.  Others  prefer 
to  fill  the  entire  cavity  with  cohesive  foil,  using  crystal  gold  at  the  cervical 
border  to  form  the  foundation  of  the  filling,  as  on  account  of  its  great  soft- 
ness it  is  easily  placed  and  can  be  readily  adapted  to  the  walls  of  the 
cavity. 

A  safe  rule  in  all  contour  work  is  to  extend  the  gold  a  little  beyond  the 
desired  line  of  contour,  in  order  that  there  may  be  opportunity  for  final 


CONSIDERATIONS   IN   FILLING   SPECIAL   CLASSES   OF   CAVITIES.       281 

shaping  and  polisMng  without  destroying  the  artistic  contour  of  the 
finished  filling.  Thorough  condensation  of  the  gold  is  an  important  factor 
in  the  stability  of  this  class  of  fillings.  Flow  of  gold  fillings  under  stress 
is  much  less,  as  shown  by  Dr.  Black,  in  fillings  that  had  been  thoroughly 
condensed  and  hardened  by  malleting  than  in  those  which  had  not  been 
malleted.  These  fillings  are  subject  to  great  stress,  and  therefore  need  to 
be  thoroughly  anchored  in  the  morsal  surface.  Fig.  423  shows  a  method 
of  anchorage  obtained  by  extending  some  portion  of  the  morsal  cavity  or 
by  its  natural  form. 

Figs.  424  and  425  represent  the  method  of  " extension  for  prevention''^ 
suggested  by  Dr.  Black  for  filling  bicuspids  and  molars.     This  method  so 

Fig.  423.  Fig.  424.  Fig.  425. 


exposes  the  margins  of  the  fillings  that  they  can  be  kept  clean  with  the 
tooth-brush,  and  it  effectually  secures  them  against  a  recurrence  of  caries 
with  ordinary  care  of  the  mouth,  provided  the  operation  has  been  properly 
performed. 

Cavities  situated  upon  the  distal  and  morsal  surfaces  of  the  bicuspids 
and  molars  unite  to  form  disto-morsal  cavities. 

These  are  no  different  from  the  class  just  described  except  in  their 
location,  which  adds  very  much  to  the  difficulties  in  filling.  All  fill- 
ings of  this  class  have  to  be  made  by  the  aid  of  reflected  light,  wliile 
the  progress  of  the  operation  is  viewed  from  the  reflected  image  in  the 
mirror. 

When  the  cavities  are  located  in  the  posterior  part  of  the  mouth,  as, 
for  instance,  in  the  second  molars  the  difficulties  of  obtaining  unobstructed 
light  and  vision  are  considerably  enhanced. 

The  operation  of  filling  may  be  greatly  simplified  by  the  adjustment 
of  a  suitable  matrix,  thus  converting  a  complicated  operation  into  a  sim- 
ple one. 

If  the  cavity  has  been  given  a  proper  retentive  form,  grooves  and  retain- 
ing-pits  will  not  be  needed,  and  the  filling  may  be  started  with  non-cohe- 
sive cylinders,  mats,  or  pellets,  thoroughly  condensed  against  the  cervical 
border  and  the  matrix,  which  must  be  firmly  fixed  in  position.  After  the 
cervical  third  of  the  cavity  has  been  filled  with  non-cohesive  gold,  the  bal- 
ance can  be  completed  with  cohesive  gold  in  the  manner  described  in  the 
preceding  class. 

Cavities  occurring  upon  the  morsal  and  buccal  surfaces  unite  to  form 
morso-buccal  cavities.  This  class  of  compound  cavities  is  usually  confined 
to  the  lower  molars  and  the  upper  third  molars.  They  can  usually  be  given 
a  good  retentive  shape  without  forming  grooves  or  retaining-pits.  In  the 
deep  cavities  non-cohesive  gold  can  be  used  for  the  base  of  the  filling  and 
then  finished  with  cohesive  foil  or  crystal  gold.  In  the  shallower  cavities 
it  is  best  to  use  cohesive  gold  throughout.     These  fillings  (Fig.  426)  are 


282  OPERATIVE    DENTISTRY. 

subjected  to  great  stress  and  wear  ;  they  should  therefore,  be  made  as  solid 
and  hard  as  possible,  that  they  may  not  be  dislodged  or  battered  by  the 
occlusion  of  the  opposing  tooth. 

Fig.  426.  Fig.  427. 


Cavities  involving  the  mortal  and  lingual  surfaces  are  usually  confined 
to  fho,  first  and  second  superior  molars. 

From  the  fact  that  these  cavities  are  generally  shallow,  they  should  be 
filled  throughout  with  cohesive  gold.  Their  position  makes  them  fairly  easy 
of  access.  The  morsal  cavity  is  usually  the  deepest,  and  may  be  quite 
large,  while  the  lingual  cavity  is  narrow  and  shallow.  In  this  case  the 
morsal  cavity  being  the  largest  should  be  filled  first,  the  smaller  cavity 
and  the  channel  uniting  them  being  filled  by  carrying  ribbons  of  foil, 
which  are  first  attached  to  the  main  filling,  over  into  the  channel  and  to 
the  cervical  extremity  of  the  lingual  cavity  (Fig.  427). 

Cavities  situated  upon  the  mesial^  distal,  and  morsal  surfaces  of  the  bi- 
cuspids and  molars,  uniting  to  form  mesio-disto-morsal  cavities,  are  of  not 
uncommon  occurrence.  These  cavities  might  be  filled  by  the  methods  de- 
scribed for  filling  the  same  class  of  cavities  occurring  in  the  incisors  and 
cuspids.  Such  operations,  however,  may  be  greatly  simplified  when  made 
in  the  bicuspids  and  molars  by  the  adjustment  of  a  matrix  to  the  distal 
surface.  The  band-matrix  is  sometimes  used,  but  this  is  not  so  satisfactory, 
as  it  obstructs  the  light  and  vision  to  a  considerable  extent.  Non-cohesive 
gold  can  be  used  to  good  advantage  in  forming  the  base,  while  cohesive 
foil  should  be  used  for  the  bulk  of  the  filling. 

Fig.  429. 


Fig.  428. 


The  filling  should  be  started  with  a  large,  soft-rolled  cylinder  placed 
at  the  disto- cervical  border  and  malleted  into  place.  Others  may  be  added 
until  the  entire  floor  of  the  cavity  and  mesio-cervical  border  are  well  cov- 
ered, after  which  cohesive  gold  may  be  used  to  complete  the  filling  (Fig. 
428). 

When  the  buccal  and  lingual  walls  are  frail  and  likely  to  fracture  under 
the  stress  of  mastication,  the  cusps  may  be  cut  away  and  the  whole  morsal 
surface  restored  with  gold.     This  operation  decreases  the  liability  to  frac- 


CONSIDERATIONS    IN    FILLING    SPECIAL    CLASSES    OF    CAVITIES.       283 

ture  and,  if  well  done,  restores  the  tooth  to  its  original  form  and  preserves 
it  for  many  years  of  usefulness.     (See  Fig.  429.) 

MATRICES. 

In  filling  compound  approximal  cavities — disto-morsal — in  bicuspids 
and  molars  with  the  various  forms  of  crystal  or  sponge  gold,  the  matrix 
will  be  found  of  great  service,  not  only  in  simplifying  the  cavity  but  in 
securing  a  more  perfect  adaptation  of  the  gold  to  the  enamel  margin,  and 
by  facilitating  the  operation.  In  fact,  many  operators  utilize  these  instru- 
ments in  filling  all  disto-morsal  cavities  in  the  posterior  teeth,  no  matter 
what  form  of  gold  may  be  used.  Their  greatest  value,  however,  lies  in 
their  use  as  just  indicated,  and  in  the  introduction  of  plastic  materials. 

In  the  introduction  of  gold  into  disto-morsal  cavities  in  the  posterior 
part  of  the  mouth,  it  is  impossible  to  use  a  straight  instrument  for  packing 
the  gold  ;  it  therefore  becomes  necessary  to  curve  or  bend  the  shaft  of  the 
plugger  near  its  point  to  suitable  angles  for  reaching  the  various  surfaces 
of  the  cavity  ;  consequently  the  force  or  impact  applied  to  the  shaft  of  the 
instrument  by  the  hand  or  the  mallet  is  not  directly  expended  upon  the 
gold  at  the  point  of  the  plugger,  but  is  more  or  less  dissipated  by  the 
elasticity  of  the  steel  at  the  curve  or  angle,  and  by  the  tendency  of  each 
impact  to  drive  the  gold  out  of  the  cavity  in  a  distal  direction.  By  the 
adjustment  of  a  suitable  matrix  a  compound  cavity  is  converted  into  a 
simple  one,  and  the  matrix  used  as  a  wall  against  which  the  gold  may  be 
packed.  Objections  have  been  raised  to  the  use  of  these  devices  on 
account  of  the  difficulty  experienced  in  giving  a  proper  contour  to  the 
approximal  surfaces,  and  of  securing  perfect  adaptation  of  the  gold  to 
the  enamel  margins  which  are  contiguous  to  the  matrix. 

These  objections  are  readily  overcome  by  a  proper  preparation  of  the 
cavity  margins,  which  leaves  them  strong  and  straight,  the  careful  adjust- 
ment of  the  matrix,  and  the  same  degree  of  skill  exercised  in  introducing 
and  condensing  the  gold  against  the  margins  that  would  be  used  in  other 
cavities. 

Several  forms  of  matrices  have  been  invented,  all  of  them  possessing 
more  or  less  valuable  features. 

The  Jack  matrices,  shown  in  Fig.  430,  are  so  shaped  as  to  provide  for 
contouring,  and  are  made  in  pairs,  adapted  for  use  upon  the  right  and  left 
sides  of  the  mouth  respectively.  These  are  held  in  place  against  the  tooth 
to  be  filled  by  wooden  wedges  driven  between  the  matrix  and  the  adjoin- 
ing tooth,  the  wedges  being  first  dipped  in  sandarach  varnish  to  keep  them 
from  slipping ;  or  it  may  be  held  in  position  by  some  quick-setting  oxy- 
phosphate  cement.  The  matrix  is  applied  by  an  especially  designed  forceps, 
which  grasps  them  firmly,  permitting  easy  adjustment  and  withdrawal. 

When  the  rubber  dam  is  used,  this  should  be  first  adjusted,  and  the 
matiix  applied  afterwards. 

The  matrix,  to  fulfil  the  object  of  its  placement,  must  be  immovably 
fixed  against  the  tooth  to  be  filled.  Motion  of  the  matrix  results  in  im- 
perfect adaptation  of  the  filling  to  the  walls  and  margins  by  reason  of  the 
difficulty  in  packing  the  gold  against  a  shifting  body. 


284 


OPERATIVE    DENTISTRY. 


To  overcome  this  difficulty,   loo][}  and  hand  matrices  were  devised  of 
various  forms  and  sizes  to  accord  with  the  differences  in  the  size  of  the 


Fig.  430. 


oo  ot 


Jack  matrices  and  forceps. 

teeth.  The  Brophy  and  the  Guilford  patterns  are  the  best  of  their  kind, 
and  are  easy  to  adjust, — these  are  shown  in  Figs.  431  and  432.  The  only 
difficulty  experienced  in  the  use  of  loop  or  band  matrices  is  to  obtain  a 
close  adjustment  at  the  cervix  of  the  tooth,  by  reason  of  the  smaller  size 

Fig.  431. 


Brophy  band  matrices. 


of  the  tooth  at  this  location  as  compared  with  the  morsal  surface  of  the 
crown.  This  difficulty  may  be  overcome  by  driving  a  wooden  wedge 
between  the  band  and  the  adjoining  tooth  at  the  cervix,  as  previously 
described. 


CONSIDERATIONS    IN    FILLING    SPECIAL   CLASSFS    OF    CAVITIES.       285 

The  Woodward  matrix  (Fig.  433)  is  also  an  ingenious  device,  and  in 
some  features  superior  to  the  others  just  described.     It  has  the  great  ad- 

FiG.  432. 


Guilford  matrices,  and  manner  of  adjustment. 


vantage  of  being  readily  adapted  to  the  cervix  of  the  tooth,  and  is  main- 
tained in  position  by  means  of  two  set  screws,  which  rest  against  the  tooth 
opposite  the  approximal  cavity  to  be  filled  and  act  as  separators. 

Fig.  433. 


Woodward  double-screw  matrices. 


A.S  the  teeth  move  under  the  pressure  of  the  screws,  it  becomes  neces- 
sary to  occasionally  tighten  them.  The  space  thus  gained  is  of  great  value 
during  the  process  of  finishing  the  filling. 


TIN-FOIL. 


Chemically  pure  tin  is  furnished  to  the  dentist  in  three  forms, — foil, 
fibrous  mats,  and  rolled  strips.  Foil  is  the  form  most  generally  used. 
This  is  beaten  after  the  same  manner  as  gold,  and  is  furnished  to  the  pro- 
fession usually  in  two  weights.  No.  3  and  No.  4,  the  figures  representing 


286  OPERATIVE    DENTISTRY. 

the  weight  of  the  foil  in  grains.  No.  3  foil  is  the  weight  in  most  general 
use. 

The  Jiby'ous  mats  or  ^''fibrous  tin'''  is  made  from  fine  shavings  of  tin 
loosely  pressed  into  mats.  This  form  of  tin  has  a  tendencj^  to  crumble, 
and  is  therefore  not  so  readily  introduced  into  the  cavity  as  foil,  neither 
has  it  any  advantages  which  are  not  possessed  in  an  equal  or  higher  degree 
by  the  foil. 

Boiled  strips  of  tin  are  about  the  weight  of  No.  20  gold- foil,  and  are 
used  in  the  same  manner  as  ribbons  of  non-cohesive  foil. 

Tin  is  one  of  the  oldest  filling-materials,  and  until  the  introduction  of 
amalgam  was  the  only  substance  at  the  disposal  of  the  dentist  for  filling 
that  class  of  teeth  which  were  not  considered  worthy  of  the  precious  metal, 
or  which  for  pecuniary  reasons  the  patient  could  not  afford  to  have  filled 
with  gold. 

It  is  much  more  ductile  and  easier  of  introduction  than  gold.  It  can 
be  more  readily  adapted  to  frail  cavity  walls,  and  when  properly  intro- 
duced makes  a  perfectly  moisture-tight  plug.  It  does  not  readily  oxidize, 
and  but  for  its  ohjectioiuible  color  and  softness  would  be  the  very  best  mate- 
rial for  filling  frail  teeth.  Tin-foil  when  first  made  is  cohesive  to  a  certain 
degree,  but  this  property  is  soon  lost  on  being  exposed  to  the  atmosphere, 
and  cannot  be  restored  by  annealing. 

The  therapeutic  action  of  tin  upon  tooth- structure  is  decidedly  antiseptic 
when  oxidation  takes  place.  For  this  reason  it  cannot  be  too  highly  recom- 
mended for  lining  the  cervical  wall  in  approximal  gold  fillings,  and  as  a 
filling-material  in  those  cases  in  which  there  is  a  persistent  recurrence  of 
caries,  associated  with  a  thick,  ropy,  tenacious  saliva,  which  in  all  proba- 
bility is  due  to  the  presence  of  gelatin-forming  micro-organisms  within 
the  mouth. 

Tin  does  not  conduct  thermal  changes  so  readily  as  gold,  and  conse- 
quently causes  much  less  irritation  to  sensitive  dentin.  This  fact  led  many 
of  the  older  operators  to  line  the  bottom  of  all  hypersensitive  cavities,  and 
those  in  which  the  pulp  was  nearly  exposed,  with  a  layer  of  tin-foil. 

Its  most  important  use  is  for  filling  the  temporary  teeth  and  first  perma- 
nent molars  of  children.  The  ease  and  rapidity  with  which  it  may  be 
inserted  and  condensed,  as  well  as  its  preservative  qualities  upon  tooth- 
structure,  make  it  the  best  material  for  this  purpose  that  the  dentist  has  at 
his  command. 

TIN   AND    GOLD. 

Tin  is  also  em]Dloyed  in  combination  with  gold-foil.  The  metals  are 
combined  in  various  proportions  ;  some  operators  enclose  a  sheet  of  No.  4 
tin  between  two  sheets  of  No.  4  gold-foil,  and  then  either  twist  it  into  a 
rope  or  cut  it  into  ribbons  ;  others  fold  a  sheet  of  No.  3  tin  in  a  sheet  of 
No.  4  gold-foil,  and  then  twist  it  into  ropes  of  various  sizes  or  cut  it  into 
ribbons  of  varying  widths  to  suit  the  case  in  hand.  The  ropes  may  also  be 
cut  into  pellets  or  the  ribbons  rolled  into  cylinders. 

This  mixture  of  the  metals  works  with  about  the  same  degree  of  soft- 
ness as  tin  alone,  and  can  be  as  readily  adapted  to  the  walls  of  the  cavity. 


CONSIDERATIONS    IN    FILLING   SPECIAL    CLASSES    OF    CAVITIES.       287 

l^on-cohesive  gold-foil  is  generally  used  in  combination  with  tin,  but 
some  oj^erators  use  cohesive  foil,  and  then  cover  the  surface  of  the  filling 
with  gold,  claiming  by  this  combination  they  are  able  to  weld  the  gold  to 
the  tin  and  gold  base. 

Fillings  which  are  made  of  tin  and  gold  combined  have  a  yellowish- 
gray  api^earance  when  first  finished,  but  they  soon  become  more  or  less 
discolored  upon  the  surface  by  oxidation. 

After  a  time  some  chemical  change,  which  at  present  is  not  understood, 
takes  place  in  the  mass,  rendering  it  exceedingly  hard  and  giving  it  the 
appearance  of  an  amalgam.  It  does  not,  however,  stain  the  tooth-struc- 
ture, as  might  be  expected,  and  seems  to  exert  a  very  decided  preventive 
effect  upon  caries.  Such  fillings  will  resist  the  attrition  of  mastication 
as  well  as  gold,  but  they  have  the  disadvantage  of  being  unsightly  in 
color,  and  should  not  therefore  be  placed  in  any  conspicuous  part  of  the 
mouth. 

Fillings  made  of  this  combination  of  metals  do  not  conduct  thermal 
changes  so  readily  as  gold  alone,  and  consequently  are  better  adapted  to 
sensitive  teeth.  Such  fillings  are  in  every  way  superior  to  amalgam,  and 
find  their  greatest  field  of  usefulness  in  the  bicuspids  and  molars  during 
the  periods  of  childhood  and  adolescence,  and  in  persons  subject  to  per- 
sistent caries. 

It  can  be  introduced  as  rapidly  as  tin  alone,  makes  a  very  durable  fill- 
ing, and  possesses  a  conserving  action  upon  tooth -structure  not  possessed 
by  gold  alone  or  by  amalgam. 

Methods  of  introducing  Tin  and  Tin  and  Gold. — The  methods 
of  introducing  fillings  composed  of  tin  and  tin  and  gold,  are  the  same  as 
those  used  in  introducing  non-cohesive  gold-foil.  Some  operators  prefer 
to  use  cylinders  and  wedge-pointed  pluggers  and  hand-pressure ;  others 
use  pellets  and  foot-shaped  plnggers  with  the  hand  or  mechanical  mallet, 
finishing  the  filling  by  driving  a  hard-rolled  pellet  into  the  central  por- 
tion of  the  plug,  and  then  thoroughly  condensing  the  surface  towards  the 
enamel  margins  with  broad-faced  pluggers  and  afterwards  thoroughly 
burnishing. 

Fillings  made  from  tin  or  tin  and  gold  combined  should  be  finished 
with  the  same  degree  of  care  and  thoroughness  as  is  expended  upon  those 
made  from  gold.  The  labor,  however,  is  much  less,  as  the  material  is  not 
so  resistant  as  gold. 

Finishing  Fillings. — The  beauty  and  the  utility  of  gold  fillings  are 
greatly  enhanced  by  perfect  finishing.  Fillings  which  have  been  well  and 
carefully  introduced  sometimes  fail  for  the  reason  that  the  margins  have 
not  been  entirely  freed  from  overhanging  portions  of  gold,  or  the  gold  has 
not  been  cut  down  and  finished  flush  with  the  enamel  margins  and  highly 
polished.  These  imperfections  are  jnost  often  found  at  the  cervical  border 
of  approximal  fillings,  particularly  in  the  bicuspids  and  molars,  where 
there  is  a  tendency  to  bifurcation  of  the  root,  and  the  cavity  extends 
beneath  the  gum,  making  a  clear  view  of  the  cervical  border  very  difficult 
to  obtain. 

Fillings  which  present  rough  surfaces  or  imperfectly  finished  margins 


288 


OPERATIVE    DENTISTRY. 


invite  recurrence  of  caries,  by  reason  of  the  fact  that  these  imperfections 
give  lodgement  to  alimentary  debris,  where  if  it  remains  undisturbed  it  is 
soon  attacked  by  the  zymogenic  bacteria,  lactic  acid  is  formed,  and  sooner 
or  later  secondary  caries  is  established.  The  importance,  therefore,  of 
perfectly  finishing  all  fillings  cannot  be  over-estimated  if  the  best  results 
are  to  be  obtained. 

In  order  to  secure  a  surface  in  a  gold  filling  that  will  receive  a  fine 
finish  thorough  condensation  is  of  the  greatest  importance.  Fillings  which 
are  imperfectly  condensed  cannot  be  made  to  take  a  smooth  and  highly 
polished  surface,  while  after  a  little  time  the  surfaces  exposed  to  wear  will 
become  rough  and  pitted. 

In  order  to  insure  a  good  surface  that  will  finish  smoothly,  many  oper- 
ators are  in  the  habit  of  using  heavy  foils  for  the  last  few  layers  of  the 
filling.  After  the  surface  has  been  thoroughly  condensed  the  burnisher 
should  be  vigorously  applied,  especially  to  the  margins,  in  order  to  obtain 
perfect  contact  of  the  gold  at  these  lines  and  to  secure  a  compact  and  hard 
surface.  Hand-burnishers  (Fig.  434)  or  those  revolved  by  the  dental 
engine  may  be  used  for  this  purpose.  The  latter  are  made  of  various 
shapes,  some  having  smooth  surfaces,  others  corrugated  surfaces,  as  shown 
in  Fig.  435. 

Fig.  434. 

3 


Hand-burnishers. 


In  all  fillings  the  cavity  should  be  filled  a  trifle  fuller  than  the  margins 
of  the  surface  in  which  they  are  located,  that  there  may  be  opportunity 
for  a  proper  shaping  of  the  surface  of  the  filling  to  harmonize  with  the 
normal  lines  of  contour. 


CONSIDEEATIONS   IN   FILLING   SPECIAL   CLASSES   OF   CAVITIES.      289 


This  shaping  or  dressing  of  simple  cavities  in  the  morsal  surface  of  the 
bicuspids  and  molars  may  be  accomplished  by  finishing-burs,  such  as  are 


Fig.  435. 


Engine-burnishers. 


shown  in  Figs.  436  and  437.  The  ^'cut''  of  these  burs  is  much  finer  than 
that  of  cavity  burs,  and  gives  the  surface  of  the  filling  a  finish  similar  to 
that  given  to  a  flat  surface  with  a  fine  file.     The  gold  should  be  cut  away 


Fig.  436. 


Fig.  437. 


Disk  burnishers. 


Flug-flnishing  burs. 


until  the  margins  of  the  cavity  have  been  reached  and  all  overlapping  por- 
tions havebeen  removed.  The  occlusion  of  the  teeth  should  next  be  noted, 
and  the  surface  of  the  filling  made  to  conform  to  the  occluding  points  or 
eminences  of  the  morsal  surface  of  the  opposing  teeth.  As  soon  as  a  natural 
occlusion  Is  obtained  the  surface  of  the  filling  should  be  polished,  using 
fine  powdered  pumice  and  water,  with  a  suitable  wood  point,  as  shown  in 
Fig.  438,  mounted  in  an  engine  porte- carrier.  If  the  operator  desires  to 
give  a  burnished  surface  to  the  filling,  this  may  be  accomplished  with  a 
suitable  engine-burnisher,  lubricated  with  a  solution  of  fine  toilet  soap  in 

water. 

Fig.  438, 


Wood  polishing-points. 

Large  fillings  in  the  morsal  surfaces  may  be  cut  down  with  suitable 
corundum  points  or  wheels.  These  instruments  cut  much  more  rapidly 
than  the  finishing-burs,  and  if  kept  wet  with  a  stream  of  water  from  the 
syringe  cause  but  little  heating  of  the  tooth.  Fig.  439  shows  a  few  of  the 
various  forms  of  these  points  and  wheels.  The  best  cutting  and  also  the 
most  durable  corundum  points  and  wheels  are  those  made  of  fine  corundum 
and  vulcanized  rubber. 

19 


290 


OPEEATIVE   DENTISTRY, 


In  the  use  of  corundum  points  for  dressing  down  the  surfaces  of  fillings 
there  is  danger,  from  the  rapidity  with  which  they  cut,  of  grinding  the 

Fig.  439. 


Corundum  points  and  wheels. 

edges  of  the  cavity  and  thus  producing  a  thin  and  weakened  margin.     A 
final  finish  may  be  given  to  the  surface  of  the  filling  by  smoothing  with 

Fig.  440. 

"'■■"■"I"-" -I'A, 


Arkansas,  Hindostan,  and  Scotch  stones. 

Arkansas  or  Hindostan  stones  of  similar  shapes  (Fig.  440)  and  polishing 

with  pumice  or  the  burnisher. 

Fig.  441. 


Labial  and  buccal  surface  fillings  are  most 
readily  finished  with  the  corundum  points, 
followed  by  the  Arkansas  stones  and  wood 
points  carrying  moistened  pumice.  The 
beauty  of  fillings  lies  in  their  perfect  mar- 
gins and  natural  contour.  Any  overlap- 
X)iug  of  the  gold  gives  the  appearance  of  a 
ragged  edge,  while  any  degree  of  deviation 
from  the  normal  convexity  of  the  surface 
detracts  from  their  beauty  of  outline.  The 
final  polishing  may  be  done  with  felt  or 
leather  polishing- wheels  or  soft  rubber  pol- 
ishiug-cups.  The  latter  are  especially  valuable  in  finishing  bucco- cervical 
fillings  in  bicuspids  and  labio-cervical  fillings  in  the  six  anterior  teeth. 


Soft  rubber  polishing-cups, 
corrugated  inside. 


CONSIDERATIONS    IN    FILLING    SPECIAL    CLASSES    OF    CAVITIES.       291 

They  are  sliown  in  Fig.  441.  If  a  dead  or  satin  finish  is  desired, — and  this 
is  best  for  the  anterior  portion  of  the  mouth,  because  it  is  less  conspicuous, 
— pumice  moistened  with  water  or  glycerol  will  be  found  most  satisfactory 
for  this  purpose,  but  if  a  brilliant  finish  is  required,  the  pumice  should 
be  followed  with  precipitated  chalk,  oxide  of  tin,  or  rouge. 

Fillings  which  are  located  upon  the  approximal  surfaces  of  the  teeth  are 
much  more  difiicult  to  finish  than  those  in  any  other  portion,  and  conse- 
quently require  a  higher  order  of  skill,  while  for  obvious  reasons  there  is 
no  class  of  fillings  which  demand  greater  care  in  their  finishing,  or  which 
repay  the  operator  a  higher  reward  for  faithful  service  rendered. 

Fig.  442. 


Plug-trimmers  and  plug-flnishing  files. 

As  a  consequence  of  the  difficulties  encountered  in  finishing  this  class 
of  fillings  a  great  variety  of  instruments  have  been  devised  to  overcome 
them.     The  oldest  of  these  are  the  thin  flat  files  cut  only  upon  one  side 

Fig.  443. 


Fig.  444. 


Approximal  trimmer. 

and  both  edges.  Some  of  them  are  made  with  a  spring  temper,  straight 
and  curved  ;  others  are  tempered  soft,  and  may  be  given  any  desired  curve 
to  suit  the  exigencies  of  the  case  in  hand.  These  are 
shown  in  Fig.  442  and  are  most  useful  in  the  anterior 
part  of  the  mouth. 

For  trimming  the  cervical  margins  of  the  filling, 
the  approximal  trimmer  shown  in  Fig.  443  is  one  of 
the  most  useful  instruments  devised  for  this  purpose. 
This  is  file-cut  upon  one  or  both  faces,  and  should  gen- 
erally be  used  with  a  drawing  motion,  the  blades  of  | 
the  file  being  set  with  that  object  in  view. 

The  sickle-shaped  knife  trimmers  of  Dr.  Gordon 
"White,  shown  in  Fig.  444  are  also  admirable  instru- 
ments for  trimming  the  cervical  margins  of  fillings. 

On  account  of  the  difficulties  experienced  in  get- 
ting a  clear  view  of  the  field  of  operation,  it  becomes 
necessary  to  examine  the  cervical  margin  by  passing 
a  fine  i^robe  or  explorer  over  this  portion  of  the  filling,   or,  better  still, 
floss-silk  may  be  made  to  pass  back  and  forth,  from  the  cervix  to  the 


Sickle-shaped  trimmers. 


292 


OPERATIVE    DENTISTRY. 


morsal  border  of  the  filling,  and  if  the  probe  does  not  catch  or  the  floss- 
silk  becomes  frayed  in  the  process,  it  may  be  presumed  that  the  over- 
lapping edges  of  the  filling  have  all  been  removed.  The  final  shaping 
of  the  filling  may  be  accomplished  by  emery  tape  or  sand-paper  strips 
drawn  back  and  forth  over  the  surface  of  the  filling.  When  the  margins 
are  all  well  defined,  the  finishing  may  be  completed  with  finer  emery, 
silex,  or  buckhorn  tape.  A  variety  of  these  strips  should  always  be  on 
hand,  comprising  all  the  grits  from  the  coarsest  to  the  finest.  The  final 
polishing  may  be  done  with  the  soft  rubber  cups  or  thin  soft  rubber  wheels 
charged  with  fine  j)umice. 

Approximal  fillings  in  bicuspids  and  molars,  because  of  the  difficulties  of 
access  which  are  x^resented  by  their  position,  make  them  the  most  trouble- 
some of  all  fillings  to  finish.  It  therefore  is  necessary  that  the  greatest 
care  be  exercised  in  this  process,  and  that  the  cervical  border  receive  par- 
ticular attention.  Fillings  which  have  been  placed  in  those  locations  with- 
out the  aid  of  a  close-fitting  matrix  usually  present  a  considerable  over- 
lapping of  the  gold  at  the  cervical  border.  The  success  of  the  filling, 
other  things  being  equal,  will  depend  largely  upon  the  perfection  with 
which  the  cervical  margin  is  trimmed  and  finished. 

In  those  cases  where  a  properly  adjusted  matrix  has  been  used,  the 
labor  of  trimming  the  margins  and  finishing  the  surface  will  be  found  to 
be  greatly  lessened. 

The  pointed,  right  and  left,  curved  files  of  Dr.  Meriam,  shown  in  Fig. 
445,  will  greatly  facilitate  the  work  of  removing  the  overlapping  edges  of 


Fig.  440. 


Dr.  Meriam's  right  and  left  plug-finishing  files. 

gold  at  the  cervical  margin,  and,  supplemented  with  the  trimmers  just 
mentioned,  will  enable  the  operator  to  give  the  desired  form  to  the  surface 
of  the  filling.     The  final  finishing  can  be  accomjplished  with  emery  tape, 

sand-paper  strips,  etc.,  after  the  manner  de- 
scribed above,   or  with  emery  cloth  or  sand- 
paper  and    cuttle-fish   disks    mounted    upon 
suitable    mandrels    for  use  with  the    dental 
engine.      These  disks    are    made  of  various 
sizes,  some  of  them  having  only  a  narrow  rim 
of  grit,  the  balance  of  the  disk  being  plain 
(Fig.  446).    The  latter  are  valuable  for  polish- 
ing the  cervical  margin  of  contour  approximal 
fillings,  as  it  enables  the  operator  to  do  this  without  cutting  away  the  con- 
tour of  the  filling  at  the  morsal  border.     Fig.  447  shows  two  of  the  popular 
forms  of  mandrels  for  carrying  these  disks. 


Thickened  rim  sand-paper  disks. 


COXSIDERATIONS    IN    FILLING   SPECIAL    CLASSES    OF    CAVITIES.       293 

Especial  attention  should  also  be  given  to  the  morsal  surface  of  those 
approximal  fillings  which  involve  this  surface  of  the  tooth,  that  perfect 
occlusion  may  be  secured.  If  the  crushing  stress  of  the  jaws  is  expended 
upon  such  a  filling,  it  is  bound,  sooner  or  later,  to  be  dislodged,  either 

Fig.  447. 


The  Morgan-Maxfield  disk  mandrel. 

from  the  flow  of  the  gold  under  stress,  the  disturbance  of  the  anchorage, 
or  from  fracture  of  the  walls  of  the  cavity.  Such  surfaces  should  be  so 
shaped  that  the  filling  will  not  be  called  upon  to  carry  more  of  the  load 
than  the  surrounding  portions  of  the  morsal  surface  of  the  crown  or' of  the 
other  teeth. 

Fillings  made  of  tin  and  tin  and  gold  are  finished  in  a  similar  manner. 

REPAIRING   DEFECTIVE   GOLD   FILLINGS. 

Gold  fillings  which  are  defective  from  imperfect  adaptation  to  an 
enamel  margin,  from  recurrence  of-  caries,  or  from  fracture,  are  often 
susceiDtible  to  rei)air. 

These  cases  many  times  present  problems  which  are  by  no  means  easy 
to  solve.  In  the  consideration  of  the  question,  each  case  offers  a  peculiar 
condition  which  makes  it  necessary  to  treat  it  upon  its  individual  needs. 
This  consideration  must  take  into  account  the  nature  of  the  defect,  its 
location  and  accessibility,  the  condition  of  the  remaining  filling,  and 
the  material  best  suited  for  repairing  the  defective  condition. 

Defects  which  are  the  result  of  imperfect  adaptation  to  an  enamel  margin  are 
usually  discovered  during  the  finishing  of  the  filling,  and  if  the  rubber  dam 
has  not  been  removed,  the  defect  may  be  readily  repaired  with  cohesive 
gold.  Sometimes  it  may  be  necessary  to  cut  away  the  filling  at  the  defec- 
tive point,  forming  a  cavity  in  it  of  retentive  shape.  If  the  filling  has 
been  in  contact  with  the  saliva,  the  rubber  dam  must  be  adjusted,  and  the 
filling  cleaned  by  bathing  it  with  alcohol,  ether,  or  chloroform,  after  which 
the  defective  point  may  be  prepared  as  above,  and  filled  with  cohesive  foil 
or  crystal  gold. 

Befects  resulting  from  recurrence  of  caries  are  most  often  found  at  the 
cervical  border  of  approximal  fillings.  Thorough  separation  of  the  teeth 
is  necessary  to  successfully  repair  such  defects. 

Defects  of  this  character  can  often  be  repaired  most  efficiently  by  using 
non-cohesive  foil  cut  in  narrow  ribbons,  and  packed  into  the  cavity  fold 
after  fold,  allowing  the  loops  to  project  beyond  the  margins  of  the  cavity, 


294  OPERATIVE    DENTJSTRY. 

and  when  the  cavity  is  full,  tliorouglily  condensing  tlie  projecting  loops 
and  finisliing  the  filling  with  emery  strips,  etc.,  in  the  usual  manner. 

If  cohesive  gold  is  used,  a  retentive  shape  must  be  given  to  the  cavity, 
and  a  groove  or  pit  provided  for  holding  in  place  the  first  piece  of  gold. 

The  bicuspids  and  molars  offer  the  most  difficult  cases  to  repair,  by 
reason  of  their  inaccessibility.  Gold  is  the  best  material  with  which  to 
make  such  repairs,  provided  the  cavity  can  be  made  accessible  ;  but  some- 
times it  is  not  possible  to  accomplish  this  except  by  removing  the  entire 
filling,  and  this,  when  the  filling  is  large  and  otherwise  good,  seems  unfair 
to  the  patient,  if  there  is  a  reasonable  assurance  of  making  a  successful 
repair  with  one  of  the  plastics.  Gutta-percha  is  often  successfully  used 
in  these  places,  but  occasionally  it  will  be  found  to  undergo  decomposition, 
and  is  therefore  not  as  reliable  as  gold.  The  oxyphosphate  cements  are 
contraindicated  on  account  of  their  tendency  to  dissolve  and  wash  out 
after  a  brief  period.  Amalgam  is  more  often  used  than  any  other  plastic 
for  this  purpose,  on  account  of  the  readiness  with  which  it  can  be  intro- 
duced into  cavities  that  are  entirely  inaccessible  to  gold,  and  the  greater 
assurance  of  making  a  good  repair.  It  has  the  disadvantage,  however,  of 
becoming  very  black  after  a  few  weeks  of  contact  with  the  gold,  but  this 
does  not  lessen  its  value  as  a  tooth  preserver.  On  account  of  the  black 
discoloration  which  always  follows  this  use  of  amalgam,  it  should  not  be 
used  in  the  anterior  teeth. 

After  the  amalgam  has  become  hard,  it  should  be  finished  as  carefully 
as  possible,  by  removing  all  overlapping  edges  and  polishing  in  the  usual 
way. 

Defects  caused  from  fracture  of  portions  of  the  ca-^dty  walls  is  a  not  in- 
frequent accident,  and  one  which  may  be  successfully  repaired,  provided 
the  filling  has  been  firmly  anchored  in  other  portions  of  the  cavity  and  the 
tooth  is  sufficiently  strong  to  warrant  the  necessary  retentive  shaping  of 
the  cavity  to  receive  the  repair. 

The  incisors  are  prone  to  such  accidents ;  the  most  common  being  the 
loss  of  the  mesio-inorsal  or  disto-morsal  angle  when  large  approximal  fillings 
are  situated  well  towards  the  morsal  edge.  Repairs  of  this  kind  are  diffi- 
cult to  make,  but  they  may  be  successfully  accomplished  by  taking  ad- 
vantage of  the  favorable  conditions  that  are  presented.  Each  case  must 
be  carefully  studied  and  treated  according  to  the  indications,  '^o  rule  can 
be  laid  down  for  such  cases.  The  operator  must  depend  upon  his  knowl- 
edge of  mechanics  and  his  ingenuity  to  suggest  a  way  to  overcome  the 
difiiculties  of  each  case  as  it  is  presented. 

Anchorage  may  sometimes  be  secured  by  drilling  a  retain ing-pit  in  the 
filling  at  one  angle,  and  another  in  the  sound  dentin  at  a  different  angle, 
or  shallow  retaining  grooves  or  channels  may  be  cut  in  the  labial  and  lin- 
gual walls  of  the  cavity  and  re-enforced  by  a  pit  drilled  into  the  filling. 
Crystal  gold  will  be  found  most  serviceable  in  this  class  of  operations. 

Accidents  of  this  character  sometimes  occur  in  the  bicuspids  and  the 
molars,  most  often  in  the  bicuspids,  especially  when  these  teeth  have  been 
filled  upon  their  mesial  and  distal  surfaces,  with  the  fillings  uniting  upon 
the  morsal  surface.     The  buccal  or  the  lingual  wall  may  be  broken  away 


CONSIDERATIONS   IN   FILLING   SPECIAL   CLASSES   OF   CAVITIES.      295 

by  stress  so  applied  between  the  cusps  as  to  split  off  tlie  weaker  of  these 
walls. 

The  prospect  of  successfully  repairing  these  cases  will  depend  ui)on  the 
security  of  the  anchorage  of  the  ap proximal  fillings,  and  the  opportunity 
for  obtaining  good  anchorage  at  the  cervical  border  and  laterally  in  the 
approximal  fillings.  When  the  buccal  wall  is  lost  it  would  be  better  prac- 
tice, for  cosmetic  reasons,  to  amputate  the  balance  of  the  crown  and  place 
an  artificial  crown  upon  the  root. 

If  the  lingual  wall  is  lost,  the  objection  to  restoring  it  with  gold  is  not 
so  strong.  Crystal  gold  gives  the  most  satisfactory  results  in  all  cases  of 
this  character. 

Occasionally  amalgam  can  be  used  for  restoring  the  lingual  cusps  of  a 
second  bicuspid,  but  the  discoloration  which  eventually  follows  makes  this 
substance  objectionable. 

Fractures  of  a  similar  character  occurring  in  the  molars  are,  as  a  rule, 
less  difficult  to  repair,  as  they  will  usually  admit  of  the  proper  retentive 
shaping  without  the  same  degree  of  danger  to  the  pulp  as  accompanies  the 
operation  in  the  bicuspids.  In  those  cases  of  fracture  which  extend 
beneath  the  gum,  the  difficulties  are  increased  by  the  hemorrhage  likely  to 
attend  the  operation,  and  the  difficulty  experienced  in  retaining  the  rubber 
dam  in  a  position  beyond  the  fracture.  .  Mack's  screws  can  sometimes  be 
set  in  such  position  as  to  offer  strong  anchorage  and  not  encroach  upon 
the  pulp.  Under  such  circumstances  they  become  a  valuable  adjunct  to 
the  other  means  of  anchorage.  Cohesive  gold  only  can  be  used  for  such 
repairs,  and  the  form  usually  indicated  is  Watts' s  crystal  gold. 


CHAPTEE    XIX. 

PLASTIC  riLLING-MATEEIALS. 

Definition. — Amalgam  (from  the  Greek  «//«,  togetlier,  and  r«/^.^a,  I 
marry),  a  combination  of  one  or  more  metals  with  mercury. 

Amalgam. — The  use  of  amalgam  as  a  filling-material  was  first  sug- 
gested in  1826  by  M,  Traveau,  of  Paris,  under  the  name  of  "Silver  Paste," 
and  it  was  first  introduced  in  the  United  States  about  the  year  1830  by 
two  Frenchmen  named  Crawcour,  under  the  high-sounding  title  of  the 
"  Eoyal  Mineral  Succedaneum."  It  was  a  purely  metallic  comi^ound,  com- 
posed of  silver  and  copper, — "  coin  silver"  (silver,  nine  i^arts  ;  copper,  one 
part), — which  had  been  reduced  to  a  coarse  powder  by  filing  and  rendered 
plastic  by  the  addition  of  mercury.  The  mixture  consisted  of  fifty  per 
cent,  of  mercury,  forty-five  per  cent,  of  silver,  and  five  per  cent,  of  copper. 
Fillings  made  of  this  compound  soon  turned  almost  a  jet-black  color  upon 
the  surface,  and  stained  the  tooth  to  an  almost  equally  dark  or  dark-green 
shade  by  the  formation  of  various  compounds  of  silver  and  copper  with 
oxygen  and  sulphur,  which  penetrated  the  tubuli  and  even  the  pulp-canal, 
the  effect  of  which,  however,  seemed  to  place  the  dental  tissues  in  a  posi- 
tion to  more  or  less  successfully  withstand  the  action  of  the  direct  causes  of 
caries,  as  was  seemingly  proved  by  specimens  of  teeth  which  had  been 
filled  with  it  for  many  years  without  further  decay. 

Some  have  thought  this  preservative  action  to  be  due  to  the  formation 
of  the  sulphate  of  copper,  which  is  an  antiseptic  of  considerable  value. 
In  corroboration  of  this  supposition  the  fact  has  been  stated  that  when 
wood  has  been  treated  with  solutions  of  sulphate  of  copper  it  is  rendered 
much  more  enduring,  as  is  known  to  civil  engineers. 

It  has  also  often  been  noticed  in  opening  old  tombs  in  England  that  in 
the  oak  cof&ns  which  had  been  put  together  with  copper  nails  the  wood 
immediately  surrounding  the  nails  was  in  a  state  of  perfect  preservation, 
while  the  balance  of  the  timber  had  literally  crumbled  to  dust  from  decay. 
The  inference  is  therefore  drawn  that  inasmuch  as  the  sulphate  of  copper 
preserves  the  wood  that  has  been  treated  with  it,  tooth-structure  will  also 
be  preserved  if  the  tubuli  are  impregnated  with  this  salt,  as  it  destroys  the 
bacteria  already  in  the  tubuli  and  renders  the  dental  tissues  an  unfavora- 
ble soil  for  the  growth  of  the  lactic-acid-producing  bacteria. 

The  merits  and  demerits  of  amalgam  as  a  filling-material  have  furnished 
a  ' '  bone  of  contention' '  over  which  the  i)rofession  has  wrangled  for  years, 
and  have  been  the  cause  of  much  heart-burning  and  bitterness.  The  strife 
and  ill-feeling  engendered  between  the  contending  parties  ran  so  high  at 
one  time  as  to  bring  about  a  professional  and  almost  a  social  ostracism  of 
those  who  dared  to  advocate  its  use. 

The  opponents  of  amalgam  looked  upon  this  material  as  an  agent  which 
was  destined  to  degrade  the  profession  and  set  at  naught  the  achievements 
296 


PLASTIC    FILLING-MATERIALS.  297 

wliicli  had  been  wrought  with  gold  as  a  material  for  filling  and  saving 
teeth. 

It  was  a  fact,  also,  in  the  earlier  years  of  the  amalgam  controversy,  that 
a  large  majority  of  those  who  used  this  material  were  men  not  worthy  of 
the  name  of  dentist,  men  who  had  not  the  skill  to  make  a  creditable  oper- 
ation with  gold  ;  hence  the  contempt  in  which  they  were  held  by  the  better 
class  of  practitioners.  This  contempt  was  also  heaped  upon  the  material 
which  had  formed  the  basis  of  the  controversy.  A  few,  however,  of  the 
better  class  of  practitioners,  who  had  a  scientific  turn  of  mind,  began  an 
investigation  into  the  merits  and  demerits  of  this  material  from  the  stand- 
point of  science,  and  finally  succeeded  in  clearing  away  much  of  error  and 
misstatement  upon  both  sides  of  the  cxuestion. 

As  a  result  of  this  labor,  the  iDrejudice  which  was  at  that  time  so  strong 
has  of  late  years  been  gradually  dying  out,  while  to-day  many  of  those 
who  were  among  its  bitterest  enemies  admit  that  under  certain  circum- 
stances and  pathologic  conditions,  amalgam  has  proved  itself  to  be  a 
very  valuable  adjunct  to  the  armamentarium  of  the  dentist  for  saving 
teeth. 

Since  the  first  introduction  of  amalgam  as  a  filling-material  many  im- 
provements have  been  made  in  its  composition  and  in  the  methods  of  its 
manipulation. 

To  the  New  Dejmrture  Triumvirate,  Flagg,  Chase,  and  Palmer,  belongs 
the  credit  of  placing  amalgam  upon  a  scientific  basis  as  a  filling-material, 
although  the  earlier  efforts  of  Townsend,  Walker,  and  Arrington  to  perfect 
this  material  by  eliminating  the  main  objectionable  feature  of  discoloration 
should  not  be  forgotten. 

Townsend,  recognizing  the  one  great  demerit  of  the  old  form  of  amal- 
gam, introduced  in  1855,  after  a  long  series  of  experiments,  an  alloy  com- 
posed of  forty-four  and  one-half  i)arts  of  pure  silver  and  fifty-five  and 
one-half  parts  of  pure  tin.  The  progress  gained  by  this  formula  was, 
however,  very  doubtful,  although  .there  was  a  marked  improvement  in  the 
tendency  to  discoloration.  This  feature  was  more  than  counterbalanced 
by  its  greater  degree  of  shrinkage,  which  caused  leakage  and  secondary 
decay. 

The  formula  forty  parts  of  silver  and  sixty  parts  of  tin  formed  the 
basis  of  all  the  various  alloys  that  were  introduced  to  the  profession  from 
the  time  of  Townsend  until  the  ISTew  Departure  Triumvirate  gave  to  the 
profession  the  results  of  its  researches  into  the  nature  and  physical  prop- 
erties of  amalgams  and  other  plastic  filling-materials.  These  studies  re- 
sulted in  a  radical  change  in  the  composition  of  the  alloys  used  in  making 
amalgams.  The  amount  of  silver  was  increased  and  the  tin  decreased,  the 
ho^ic  formula  being  sixty  parts  of  silver  to  forty  parts  of  tin. 

The  introduction  of  more  scientific  methods  in  the  manufacture,  prep- 
aration, and  manijDulation  of  amalgam  and  the  other  plastic  filling-mate- 
rials has  greatly  increased  their  usefulness  as  therapeutic  agents,  and  made 
it  possible  for  the  i)Oor,  by  a  limited  expenditure  of  money,  to  have  their 
teeth  cared  for  and  saved  for  years  of  comfort  and  usefulness,  while,  upon 
the  other  hand,  the  more  exact  knowledge  gained  of  the  nature  of  their 


298  OPERATIVE    DENTISTRY. 

physical,  chemical,  and  therapeutic  properties  has  made  it  possible  to 
apply  them  to  particular  pathologic  conditions  with  a  reasonable  assurance 
that  they  will  fulfil  the  requirements  of  the  individual  state  or  condition 
for  which  they  were  applied. 

THE   NATURE   AND   PROPERTIES   OF   AMALGAM. 

One  or  more  metals  held  in  combination  with  mercury  is  termed  an 
amalgam.  Two  or  more  metals  combined  by  melting  are  termed  an  alloy. 
No  combination  of  metals  can  be  called  an  amalgam  until  they  have  been 
combined  with  mercury ;  hence  the  combinations  of  metals  used  for  the 
purpose  of  making  an  amalgam  should  be  termed  dental  alloys,  and  not 
amalgams.  No  mixture  or  combination  of  metals  can  be  regarded  as  an 
amalgam  unless  it  has  mercury  as  one  of  its  component  parts,  and  that  ^ '  in 
sufficient  quantity  to  exert  a  combining  influence  over  the  other  metals." 
(Flagg.) 

Amalgams  are  classified  according  to  the  number  of  metals  which  they 
contain.  Those  containing  two  metals — as,  for  instance,  copper  and  mer- 
cury— are  termed  binary  ;  those  containing  two  metals  in  combination  with 
mercury  are  termed  ternary ;  those  containing  three  in  combination  with 
mercury  are  known  as  quaternary  amalgams. 

Mercury  has  the  property  of  dissolving  or  melting  certain  other  metals 
of  a  higher  fusing  character.  '■ '  The  combinations  thus  formed  are  in  the 
case  of  solid  amalgams  definite  compounds,  but  in  which  there  is  only  a 
feeble  chemical  affinity  between  the  constituents.  Liquid  amalgams  are 
merely  solutions  of  the  various  metals  in  mercury,  and  not,  as  a  rule, 
definite  chemical  compounds."     (Watts.) 

Amalgams,  however,  may  with  correctness  be  classed  as  alloys.  Mat- 
th lessen  has  suggested  that  "an  alloy  may  be  either  (1)  a  solution  of  one 
metal  in  another,  (2)  a  chemical  combination,  (3)  a  mechanical  mixture, 
or  (4)  a  solution  or  mixture  of  two  or  all  of  the  foregoing." 

Kirk  is  of  the  oi^inion  that  in  combijiing  mercury  with  dental  alloys  a 
chemical  combination  is,  formed.  He  says,  "In  all  amalgams  which  possess 
the  quality  of  setting  or  hardening  from  a  plastic  mass,  we  have  to  deal 
almost  certainly  with  a  chemical  combination.  The  property  of  setting  is 
in  itself  an  evidence  of  chemical  combination,  and  the  formation  of  many 
amalgams  is  attended  with  elevation  of  temperature,  more  or  less- marked, 
which  is  another  indication  of  chemical  combination.  Changes  of  the 
volume  of  the  mass  attendant  upon  the  act  of  setting  still  further  indicate 
that  chemical  union  of  some  portion  of  the  constituent  elements  of  the 
amalgam  has  taken  jjlace." 

The  Physical  Properties  of  Amalgam. — The  peculiar  i)hysical 
properties  of  amalgams  are, — viz.,  setting,  contraction,  expansion,  flow, 
stability,  color,  conductivity. 

Setting. — Du  Bois  says,  "  Our  present  theory  in  regard  to  the  forma- 
tion of  an  amalgam  is,  that  metals  which  melt  at  comparatively  high  tem- 
peratures when  brought  under  the  fusing  influence  of  mercury — which  re- 
mains liquid  at  a  temperature  of —30°  F.— are  melted  into  union  with  it." 
The  setting,  hardening,  or  crystallizing  of  the  mass  is  therefore  due  to  the 


PLASTIC    FILLING-MATERIALS.  299 

secondary  cooling  effect  exerted  upon  the  mercury  by  the  admixture  of  those 
metals  which  possess  a  high  fusing-point,  and  that  the  higher  the  fusing- 
point  of  the  metals  amalgamated,  the  more  rapid  will  be  the  process  of 
setting.     Platinum,  however,  presents  an  exception  to  this  rule. 

Amalgams  are  decomposed  by  the  application  of  heat  sufficient  to 
volatilize  the  mercury  which  holds  the  other  metals  in  combination. 

During  the  process  of  setting,  and  for  some  time  thereafter,  nearly  all 
amalgams  undergo  a  change  in  volume  and  form.  This  change  in  volume 
may  be  either  a  contraction  or  an  expansion. 

Contraction  and  Expansion. — Contraction,  or  "shrinking,"  and  ex- 
pansion, or  "bulging,"  of  amalgams  is,  according  to  Flagg,  in  a  general 
way  in  harmony  with  the  natural  contraction  or  expansion  of  the  metals 
composing  it,  when  passing  from  a  fluid  to  a  solid  state.  Those  metals 
which  lose  their  fluidity  slowly,  like  tin,  for  instance,  cause  the  greatest 
amount  of  contraction,  while  metals  like  gold  and  copper,  which  lose 
their  fluidity  quickly,  and  silver,  which  expands  when  passing  from  the 
fluid  to  the  solid  state,  exert  a  controlling  influence  upon  contraction. 

The  contraction  of  an  amalgam  filling  produces  "cupping  of  the  sur- 
face and  a  drawing  away  of  the  mass  from  the  walls  of  the  cavity,  while 
exxmnsion  of  an  amalgam  produces  bulging  of  the  surface. 

Black  has  shown,  in  his  studies  upon  the  "Physical  Character  of  Amal- 
gams, ' '  etc.  {Dental  Cosmos,  1895),  that  contraction  and  expansion  of  dental 
amalgams  are  influenced  by  many  factors, — viz.  : 

"  (1)  To  the  composition  of  the  alloy. 

"  (2)  To  the  fineness  of  the  cut  of  the  alloy. 

"  (3)  To  the  amount  of  mercury  used  in  amalgamation. 

"  (4)  To  the  evenness  with  which  the  mercury  is  distributed. 

"(5)  To  the  method  of  manipulation." 

Dental  alloys  which  are  composed  of  silver  and  tin — the  tin  in  excess  of  the 
silver — contract  very  considerably  during  the  process  of  setting,  Avhile  in 
those  containing  silver  in  excess  the  contraction  is  notably  lessened.  The 
proportions  of  these  metals  which  will  produce  an  amalgam  with  the  mini- 
mum amount  of  contraction  has  been  demonstrated  by  Flagg,  and  later 
by  Black,  to  be  silver  sixty-five  per  cent.,  tin  thirty-five  per  cent.  Ee- 
ducing  the  amount  of  silver  and  increasing  the  tin  produces  an  alloy 
which  will  form  a  contracting  amalgam,  while  increasing  the  silver  and 
decreasing  the  tin  produces  an  expanding  amalgam. 

Black  in  his  experiments  found  that  in  all  silver-tin  amalgams  in  which 
the  percentage  of  silver  was  below  sixty  per  cent,  contraction  was  the 
rule,  the  amount  of  contraction  seemingly  being  governed  by  the  relative 
proportions  of  the  silver  and  tin  contained  in  the  alio}'.  He  also  found 
that  contraction  occurred  during  the  first  twenty-four  hours,  being  greatest 
during  the  first  two  hours.  A  slight  compensating  expansion  then  occurred, 
lasting  for  from  one  to  three  days.  During  the  process  of  expansion  the 
amalgam  softens  very  materially.  This  process  he  thinks  is  normal  to  all 
amalgams  containing  less  than  sixty  per  cent,  of  silver,  as  its  absence  is 
the  exception.  Slight  contraction  again  follows  the  expansion,  and  this 
he  thinks  extends  over  an  indefinite  period. 


300  OPERATIVE   DENTISTRV. 

In  alloys  containing  more  than  sixty  per  cent,  of  silver  there  is  no 
primary  contraction,  while  iu  those  containing  eighty  per  cent,  of  silver 
and  twenty  per  cent,  of  tin  the  expansion  was  very  great,  causing  bulging 
or  "  spheroiding"  of  the  surface  of  the  filling.  This  condition  was  always 
notably  present  in  the  old,  coin  silver  amalgam,  which  contained  ninety 
per  cent,  of  silver. 

The  fineness  of  the  cut  of  the  alloys,  also,  seems  to  exert  an  influence  upon 
the  contraction  and  expansion  of  amalgams  containing  fifty  to  sixty  per 
cent,  of  silver,  for  Black  found  alloys  of  the  same  grade  or  composition,  if 
cut  fine  or  comminuted  into  very  fine  particles,  always  contracted  much 
more  than  when  cut  in  moderately  coarse'  filings.  This  was  a  constant 
condition  with  this  grade  of  amalgam.  He  was  unable  to  definitely  ex- 
plain this  condition,  but  states  the  facts  that  the  reduction  of  the  alloy  to 
such  fine  particles  causes  them  to  take  up  more  mercury,  and  that  the  re- 
sulting amalgam  is  much  softer  and  contraction  greater. 

The  percentage  of  mercury  contained  in  amalgam  influences  the  con- 
traction and  expansion  to  a  greater  or  less  degree.  Black  says,  however, 
that  it  "is  not  so  important  a  factor  in  the  contraction  of  amalgam  as  he 
had  supposed,  and  yet  when  the  mass  has  been  worked  very  dry  the  change 
of  bulk  has  been  markedly  less,  whether  contraction  or  expansion."  An 
excess  of  mercury  in  contracting  amalgams  increases  the  contraction,  while 
in  expanding  amalgams  it  increases  the  expansion. 

He  found  that  "  soft  fillings,  or  fillings  made  from  a  mass  containing 
fifty  per  cent,  or  more  of  mercury,  showed  great  irregularity  in  contrac- 
tion." 

This  author  also  found  that  a  difference  of  five  per  cent,  of  mercury, 
or  even  more,  in  the  fifty  to  sixty  per  cent,  silver  alloys,  did  not  materially 
affect  the  contraction,  but  when  the  mass  was  so  dry  that  no  mercury  could 
be  worked  to  the  surface  in  the  process  of  packing  it  into  the  cavity,  there 
was  a  marked  lessening  of  the  contraction. 

The  amount  of  mercury  required  to  amalgamate  the  different  alloys 
depends  largely  upon  the  per  cent,  of  silver  which  they  contain.  This 
fact  has  long  been  recognized. 

Black  found  that  the  increase  of  mercury  to  form  a  workable  mass  was 
not  very  noticeable  until  the  amount  of  silver  passed  beyond  sixty-five  per 
cent. ;  but  with  seventy  per  cent,  silver  alloys  it  became  very  difficult  to 
amalgamate  them  with  fifty  per  cent,  of  mercury  j  while  with  eighty  per 
cent,  of  silver,  sixty  per  cent,  of  mercury  was  necessary  to  form  a  work- 
able amalgam.  The  increase  in  expansion  became  very  notable  with  the 
increase  in  the  percentage  of  mercury. 

He  also  discovered  that  an  increase  of  mercury  was  necessary  for  com- 
plete amalgamation  of  those  alloys  which  contained  less  than  sixty  per 
cent,  of  silver,  though  this  increase  was  much  less  marked.  Alloys  which 
contain  sixty  per  cent,  of  silver  require  less  mercury  to  form  a  good 
workable  mass  than  those  containing  any  other  proportion. 

These  facts,  and  many  others,  are  most  graphically  shown  in  the  accom- 
panying table  or  exhibit  of  Dr.  Black,  "On  the  Contraction  and  ExpauwSion 
of  Amalgrams." 


PLASTIC   FILLING-MATERIALS. 


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PLASTIC    FILLING-MATERIALS. 


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306  OPERATIVE    DENTISTRY. 

Tt  will  be  noticed  by  a  reference  to  this  exhibit  that  formula  'Ro.  1— 
silver  65,  tin  35,  mercury  44.60,  mixed  in  the  hand— gave  the  best  results, 
there  being  no  change  in  volume  by  either  contraction  or  expansion  at  the 

sixth  day. 

The  evenness  with  ivhich  the  mercury  is  distributed  through  the  mass  appears 
to  be  a  controlling  factor  in  the  contraction  and  expansion  of  amalgams. 
This  investigator  found  that  wringing  or  compressing  the  mass  in  a  piece 
of  linen  or  chamois-skin  had  the  effect  of  improving  the  amalgam  both  in 
its  working  qualities  and  in  the  stability  of  the  final  product,  independently 
of  the  removal  of  an  excess  of  mercury,  especially  if  the  compression  is 
maintained  for  a  little  time.  This  he  found  to  be  the  case  when  the  amal- 
gam was  so  dry  that  no  mercury  could  be  squeezed  out  of  it,  and  suggests 
that  the  steady  compression  has  the  effect  of  producing  an  even  distribu- 
tion of  the  mercury  through  the  whole  mass. 

The  method  of  manipulation  was  also  found  by  Black  to  be  an  important 
factor  in  controlling  contraction  in  contracting  amalgams  and  in  obtaining 
good  margins.  In  packing  amalgams,  he  recommends  that  it  should  be 
introduced  layer  by  layer,  and  the  pressure  so  applied  as  to  thoroughly 
condense  the  mass,  without  breaking  it  up  or  kneading  it,  and  the  softened 
material  cut  away  with  sharp  spoon-shaped  excavators  before  another  layer 
is  added,  this  process  to  be  repeated  until  the  cavity  is  full  and  a  fine  hard 
surface  remains.  To  obtain  good  margins,  the  mass  should  be  carefully 
compressed  against  the  walls  with  a  small  instrument,  but  in  such  a  way  as 
not  to  break  up  the  integrity  of  the  partially  packed  material. 

Floiv  of  amalgams, — change  of  mass  from  molecular  motion  under  stress. 
This  is  a  property  which  has  been  observed  to  be  possessed  by  the  majority 
of  metals,  and  described  as  the  Jloiv  of  solids,  but  hitherto  entirely  unsus- 
pected as  a  property  of  amalgams  until  Black  discovered  it.  In  the  ' '  flow" 
of  metals,  iron,  steel,  gold,  silver,  etc.,  except  tin  and  a  few  of  the  softer 
metals,  a  given  stress  will  cause  the  metal  to  yield,  spread,  or  flow.  The 
phenomena  occur  immediately,  and  cease  after  a  period  of  from  one  to  two 
minutes  after  the  stress  is  applied,  even  though  the  stress  be  maintained. 
The  application  of  greater  stress  causes  an  increased  flow,  which  again 
ceases  until  still  greater  stress  is  applied. 

Black  has  discovered  that  the  flow  of  dental  amalgams  is  very  different 
from  this.  He  says,  ' '  When  the  flow  of  amalgam  has  begun,  it  continues 
so  long  as  stress  is  maintained.  No  increase  of  the  stress  is  required  to 
maintain  the  flow,  even  after  the  area  of  the  amalgam  has  been  greatly 
increased  by  the  flattening  of  the  mass  between  plain  surfaces.  If  a  stress 
of  fifty  pounds  be  put  upon  a  block  of  amalgam  one-tenth  of  an  inch  square, 
and  maintained  for  one  hour,  flow  will  occur  at  a  certain  rate  ;  if  the  stress 
is  reduced  to  twenty-five  pounds,  the  flow  will  continue,  but  at  a  reduced 
rate.  There  is  a  manifest  disposition  of  the  material  to  creep  out  from 
under  a  load.  It  will  go  slowly  with  a  light  stress,  somewhat  quicker  with 
a  heavier  one,  but  it  cannot  be  made  to  go  very  quickly  with  a  very  heavy 
stress  ;  but  will  instead  break  into  fragments." 

This  investigator  also  discovered  that  there  was  a  vast  difference  in  the 
strength  of  amalgams  under  stress. 


PLASTIC    FILLING-MATERIAI.S.  307 

Exhibit  of  the  Physical  Properties  of  Silver-Tix  Amalgams. 


5'^ 

p 


"^  o 
£53 

4 

33.26 

1 
1 

30.90 
35.77 

4 

2.91 

4 

4.82 

2 
2 

5.07 
8.32 

2 

5.82 

6 

4.89 

6 
5 
5 

8.61 
9.00 
9.76 

3 

2.44 

1 
1 

1.89 
4.10 

4 

7.57 

1 
1 
4 
1 
1 

5.12 
6.56 
11.75 
6.72 
9.33 

3 

26.55 

1 
1 
3 

1 

1 

20.49 
22.95 
30.65 
31.97 
40.16 

3 

25.64 

1 
1 

22.76 
26.23 

3 

26.28 

1 
1 

15.78 
28.70 

3 

19.81 

1 
1 
4 

15.57 

24.59 
25.14 

3 

27.59 

3 

2 

34.91 
36.11 

A  mechanical  mix  of  precipitates 
of  the  metals.  Materials  fur- 
nished by  Dr.  Ames,  of  Chicago 

Pressed  in  with  serrated  points,  re- 
moving no  mercury 

Burnished  in ". 

Weighed  and  mixed  and  used 
without  wringing  out;  fillings 
made  at  once 


Fillings  made  after  forty  minutes 

Made  with  hot  instruments,  after 

fifty  minutes 


As  the  blocks  were  made  the  odd 
numbers  were  placed  in  one 
box  and  the  even  numbers  in 
another,  so  that  they  should  be 
alike,  and  the  tests  made  two 
days  apart. 


Pressed  in 

Burnished  in. 


Pressed  in. . . 
Burnished  in 

Pressed  in... 
Burnished  in 


Pressed  in . . . 
Burnished  in 

Pressed  in.. . 
Burnished  in 


Pressed  in 

Burnished  in. 


Pressed  in 

Burnished  in. 


Pressed  in 

Burnislied  in. 


Made  with  hot  points. 


f  Silver  60 

\  Tin  40 


/  Silver  60 

t  Tin  40 


.45  \ 
.55/ 


42.45 
57 


53.22 

45.88 

0.45 

0.45 


f  Silver 
ITin 


f  Silver 
J.  Tin 
(Copper 


f  Silver 
J  Tin 
]  Copper 
[Bismuth 


(Silver 
-^Tin 
(Gold 


Silver  60      ) 

Tin  37      y 

Gold  3      j 


Silver         48.5 
Tin  48.5 

Platinum     3.0 


Silver  44.81 

Tin  52.78 

Gold  1.87 

Platinum  0.62 


Silver  54.86') 

Tin  44.89  V 

Zinc  0.25  j 


.55.61 
55.61 


38.58 
41.04 


40.00 
40.00 


40.00 


40.  .59 
40.59 
39.05 
39.05 


32.66 


32.66 
32.66 


39.08 

39.08 
39.08 
38,71 
38.71 
38.71 


31.92 

31.92 

31.92 
40.18 
40.18 
40.18 


30.31 
30.31 


26.47 
26.47 


37.45 

37.45 
37.45 
36.75 


40.65 
40.65 


Mortar 


Mortar 
Mortar 


Hand 
Mortar 


Hand 
Hand 


Hand 


Hand 
Mortar 
Mortar 


Hand 
Hand 


Hand 
Hand 

Mortar 
Mortar 
Mortar 


Hand 

Hand 
Hand 
Mortar 
Mortar 
Mortar 


Hand 


Hand 
Hand 


Hand 


Hand 
Hand 


Hand 

Hand 
Hand 
Mortar 


Mortar 
Mortar 


160 


277 
255 


250 
2.50 


230 

230 
235 
220 


315 


253 


257 


210 


225 


225 


225 


308  OPERATIVE   DENTISTRY. 

Exhibit  of  tmk  Physical  Properties  op  Silver-Tin  Amai.gams.— Continued. 


t- 

xn  u 

u  >        i. 

o 

S 

tIo 

^  o 

"oo 

0) 

a 

•^s 

S  ^ 

Notes. 

No. 

Formulae. 

2 

h 

C  0)  ? 

^5 

o 

5.5 

Ph 

W 

p 

12; 

< 

Ch 

r  Silver 

54.861 

11 

I  Tin 
1  Zinc 

44.89  1 
0.25  f 

40.89 

Hand 

2 

3 

26.92 

2.50 

[Palladium  0.25  J  | 

AladG  witli  liot  points 

11 
11 

' 

40.89 
40.61 

Hand 
Mortar 

2 
2 

2 
3 

19.. 55 
14.96 

260 

11 

1' 

.33.01 

Hand 

2 

4 

16.34 

275 

11 

■  Silver 
Tin 

41.92] 
56.33  1 

36.29 

Mortar 

2 

4 

22.44 

252 

12 

■  Platinum 
Zinc 
Bismuth 

0.44  >■ 
0.8S 
0.44  J 

38.46 

Hand 

3 

3 

16.53 

207 

Pacljed  lightly,  without  removing 
any  mercurv 

12 

« 

41.43 

Hand 

3 

3 

11..33 

195 

Packed  heavily  with  small  points, 

removing  all"  mercury  possible. . 

12 

" 

41.43 

Hand 

3 

3 

19.92 

Mixed  without  wringing  out  and 

packed  lightly  without  remov- 

ing any  mercury 

12 

f  Silver 

47.061 

.50.00 

Hand 

3 

3 

11.26 

160 

Pressed  in 

13 

J  Tin 

51.70  1 

41.00 

Hand 

2 

3 

25.09 

235 

Burnished  in 

13 

1  Cotrner 

0.94  f 

[Zinc 

0.24  J 

" 

38.74 

Mortar 

2 

3 

24.48 

237 

Silver 

42.83] 
51.62 

Tin 

14 

-  Copper 

4.65  y 

35.95 

Hand 

2 

3 

14.22 

220 

Aluminum  0.55  | 

Gold 

0.01  J 

Pressed  in 

14 

" 

35.95 

Hand 

4 

1 

4.09 

Burnished  in 

14 

" 

.35.95 

Hand 

4 

1 

8.13 

14 

" 

31.15 

Mortar 

2 

3 

28.44 

200 

14 

" 

31.15 

Mortar 

4 

1 

16.40 

14 

" 

31.15 

Mortar 

4 

1 

17.50 

Experimental  alloys  made  by  Dr. 

P.  ,1.  Kester,  of   Chicago,   espe- 
cially for  investigation 

1.5 

J  Silver 
JTin 

70      1 
30      J 

50.00 

Hand 

2 

4 

4.28 

300 

(No  mercury  could  be  removed 

15 

„ 

50.00 

Mortar 

2 

3 

4.12 

345 

from    these    mixes    by    wringing 
through  muslin.) 

15 

" 

50.00 

Mortar 

5 

3 

5.71 

360 

(With  50  per  cent,  of  mercury 

16 

f  Silver 
ITin 

80      ■( 
20     ; 

50.00 

Hand 

2 

4 

7.41 

275 

the  mix  was  a  dark,  semi-coheren't 

powder  that  was  extremely  diffi- 

16 

" 

50.00 

Mortar 

2 

3 

9.23 

280 

cult  to  pack.) 

16 

" 

60.00 

Hand 

2 

3 

2.40 

330 

(These  mixes  worked  easily  and 

16 

" 

60.00 

Hand 

5 

3 

8.50 

340 

well,    only    that    they    set    very 

16 

" 

60.00 

Mortar 

2 

3 

4.24 

315 

quickly.) 

16 

** 

1  60.00 

Mortar 

5 

3 

4.50 

325 

Note. — In  the  above  experimental  alloys  the  increase  of  mercury  required  as  the  tin  is  diminished  is 
very  notable.  It  shows  that  after  a  certain  point,  n.ot  yet  accurately  determiiied,  we  cannot  diminish 
the  flow  by  diminishing  the  percentage  of  tin. 


The  foregoing  table  gives  the  iiow,  crushing  stress,  etc.,  of  a  series 
of  experiments  conducted  by  Dr.  Black  with  sixteen  different  formulae  for 
dental  amalgams. 

The  flow  of  jDure  silver-tin  alloj^s  was  found  to  range  from  two  and  one- 
"half  per  cent,  to  ten  per  cent,  under  a  stress  of  sixty  pounds,  the  differ- 
ence depending  upon  the  composition  of  the  alloy,  the  fineness  of  the  cut, 
and  the  special  mode  of  manipulation. 

The  silver-tin  formulae  ranged  in  composition  from  forty  per  cent,  of 
silver  and  sixty  per  cent,  of  tin  to  sixty  per  cent,  of  silver  and  forty  per 


PLASTIC    FILLING-MATERIALS.  309 

cent,  of  tin.  The  addition  of  a  small  per  cent,  of  copper  had  a  tendency 
to  somewhat  diminish  the  flow  and  give  greater  strength  under  stress. 
All  other  metals  which  enter  into  the  composition  of  dental  alloys  mark- 
edly increase  the  flow  of  the  amalgam^  but  do  not  seem  to  materially  injure 
the  strength  of  the  amalgam  under  stress.  He  thinks,  however,  that  the 
crushing  strength  of  an  amalgam  is  not  a  test  of  its  stability  under  stress, 
but  looks  upon  the  amount  of  floio  as  the  important  test.  The  great  difficulty 
with  the  silver-tin  amalgams  is  that  they  will  gradually  change  in  form 
under  the  stress  of  mastication,  as  was  demonstrated  in  the  laboratory  ex- 
periments by  subjecting  specimens  of  hardened  amalgam  to  an  intermittent 
stress. 

The  copper  amalgams  do  not  flow  under  stress,  and  the  margins  remain 
perfect.  This  was  not  the  case  with  the  silver-tin  amalgams.  Their  disposi- 
tion to  flow  under  the  stress  of  mastication  allows  them  to  move  in  the 
cavity,  and  on  account  of  this  movement  they  do  not  retain  perfect  mar- 
gins, and  thus,  after  a  time,  the  way  is  opened  for  the  establishment  of 
secondary  caries  by  reason  of  the  re-entrance  of  the  active  agents  of  the 
disease. 

A  careful  study  of  the  table  in  reference  to  the  relative  influence  of  the 
various  metals  entering  into  the  com]30sitiou  of  dental  alloys  upon  the  flow 
of  amalgams  will  be  found  to  be  exceedingly  interesting,  from  the  fact 
that,  coux)led  with  the  discovery  that  all  silver-tin  alloys  containing  less 
than  sixty  per  cent,  of  silver  contract  or  shrink  during  the  process  of 
setting  and  for  some  time  thereafter,  it  explains  the  condition  which  after 
a  few  months  or  years  almost  universally  exists, — defective  margins  and 
imxDcrfect  adaptation  to  the  walls  of  the  cavity  of  fillings  made  from  these 
alloys. 

Annealing.— Dr.  Black  also  made  another  important  discovery  while 
experimenting  with  alloys  made  by  himself  as  to  the  influence  of  time 
upon  cut  alloys,  or  aging  of  the  alloy,  as  it  has  been  termed. 

Flagg,  in  his  work  on  "Plastics  and  Plastic  Fillings,"  claims  that  freshly 
cut  alloys  do  not  mix  as  well,  neither  do  they  give  as  good  "setting," 
^ '  shrinkage, "  "  edge-strength, "  or  "  color' '  tests,  as  when  properly  ' '  aged. ' ' 

Black  in  his  experiments  found  the  opposite  of  this  to  be  true  in  rela- 
tion to  the  shrinkage  test.  Freshly  cut  alloys  which  when  made  into 
amalgams  did  not  shrink,  or  might  expand,  were  invariably  found  to 
shrink  after  aging.  The  explanation  of  this  j^henomenon  at  first  seemed 
to  be  due  to  a  slight  oxidation  of  the  particles  of  the  cut  alloy,  by  which 
its  chemical  relations  to  mercury  were  profoundly  changed.  Further  ex- 
perimentation, covering  several  months  of  time,  finally  demonstrated  the 
fact  that  neither  oxidation  nor  time  had  anything  whatever  to  do  with  the 
working  qualities  or  the  shrinkage  of  dental  alloys.  During  these  experi- 
ments the  influence  of  temperature  in  aging  of  alloys  was  accidentally 
brought  to  his  notice.  He  immediately  set  to  work  to  verify  or  prove  the 
error  of  the  influence  of  this  new  factor,  and  finally  discovered,  after  ex- 
haustive experiments,  that  the  change  was  due  to  a  molecular  alteration 
in  the  particles  of  the  cut  alloy,  induced  by  heat,  or,  in  other  words,  it  was 
due  to  a  process  of  annealing  or  tempering.     Various  degrees  of  tempera- 


310  OPERATIVE    DENTISTRY. 

ture  were  used,  ranging  from  110°  to  212°  F.  ;  but  the  lower  tempera- 
ture produced  the  best  results.  130°  F.  was  found  to  be  the  temperature 
which  produced  the  greatest  amount  of  shrinkage. 

Each  alloy  was  found  to  have  a  definite  ^^ shrinkage  expansion  range.^'' 
In  some  this  range  is  all  shrinkage,  in  others  all  expansion,  and  in  still 
others  it  is  both  expansion  and  shrinkage.  It  was  also  found  that  by 
annealing  or  tempering  any  of  the  shrinking  or  expanding  alloys  these 
physical  properties  could  be  reduced  to  any  amount,  provided  the  tem- 
perature was  maintained  for  a  certain  period. 

Each  alloy  has  its  zero  point  of  contraction  or  expansion,  beyond 
which  no  amount  of  annealing  has  any  effect. 

''The  modified  silver- tin  alloys  that  have  seventy-five  per  cent,  of 
silver  or  more  expand  only.  They  cannot  be  made  to  shrink  by  aging, 
though  their  exxjansion  can  be  greatly  reduced.  The  same  class  of  alloys 
containing  as  much  as  sixty-five  per  cent,  of  silver  and  less  than  seventy- 
five  per  cent,  expand  when  freshly  cut,  and  shrink  when  fully  aged  or 
tempered.  Those  containing  from  fifty  to  sixty-one  or  sixty-two  per  cent, 
of  silver  shrink  only,  but  shrink  much  more  when  aged  than  when  freshly 
cut.  Those  that  contain  less  than  fifty  per  cent,  of  silver  first  shrink  and 
then  expand.  When  fresh  cut  the  expansion  is  the  greater,  when  aged 
the  shrinkage  is  the  greater. 

"Alloys  which  contain  sixty-five  to  seventy-five  per  cent,  of  silver 
are  hard,  and  make  hard  and  quick-setting  amalgams  ;  they  are  also  the 
strongest  amalgams  that  can  be  made  of  silver  and  tin.  Alloys  containing 
less  than  sixty- five  i)er  cent,  of  silver  are  soft,  and  make  soft,  slow-setting 
amalgams.  Alloys  containing  more  than  seventy-five  per  cent,  of  silver 
are  soft,  and  make  frail,  slow-setting  amalgams  ;  the  slow-setting  property 
occurs  somewhat  suddenly  after  passing  the  seventy-five  per  cent. 

' '  Alloys  which  suffer  no  alteration  in  volume  when  unannealed  shrink 
when  annealed." 

The  tables  given  on  page  311  show  the  extent  of  the  change  produced 
in  the  alloys  by  the  process  of  annealing  in  the  unmodified  and  the  modified 
silver- tin  alloys,  and  the  influence  of  the  modifying  metals  also  upon  the 
shrinkage,  expansion,  flow,  and  crushing  strength.  They  also  demonstrate 
the  fact  that  less  mercury  is  required  to  amalgamate  a  given  sample  of  alloy 
when  annealed  than  when  unannealed,  and  that  both  the  flow  and  crush- 
ing stress  of  amalgams  made  from  annealed  alloys  are  slightly  increased. 

Stability. — ^The  physical  property  of  amalgams  designated  as  stability 
or  rigidity  \B  the  antithesis  of  "flow."  That  amalgam  is  the  best,  other 
things  being  equal,  which  flows  the  least, — in  other  words,  is  most  stable, 
shrinks  the  least,  and  has  the  highest  crushing  strength.  Such  amalgams 
have  been  said  to  possess  great  "edge-strength." 

The  term  "edge-strength"  was  invented  to  designate  the  degree  of  re- 
sistance an  edge  or  an  angle  of  hardened  amalgam  offers  to  a  force  which 
on  being  applied  might  cause  it  to  be  fractured. 

It  is  evident,  however,  from  the  discovery  of  the  property  of  flow  under 
stress  possessed  by  the  "unmodified"  and  the  "  modified"  silver- tin  amal- 
gams, that  it  will  be  necessary  to  modify  all  former  notions  in  relation  to 


PLASTIC    FILLING-MATERIALS. 

Exhibit  of  Unmodified  Silver-Tin  Alloys. 


311 


How  prepared. 

Per  cent. 

of 
Mereurj'. 

Shrinkage. 

Expansion. 

Flow. 

Crushing 

Silver. 

Tin. 

Stress. 

40 

60 

Fresh-cut. 

45.78 

6 

7 

40.15 

178 

40 

60 

Annealed. 

34.14 

9 

3 

44.60 

186 

45 

55 

Fresh-cut. 

49.52 

4 

8 

25.46 

188 

45 

55 

Annealed. 

32.13 

11 

1 

28.57 

222 

50 

50 

Fresh-cut. 

51.18 

2 

2 

22.16 

232 

50 

50 

Annealed. 

37.58 

17 

1 

21.03 

245 

55 

45 

Fresh -cut. 

51.62 

2 

2 

19.66 

245 

55 

45 

Annealed. 

40.11 

18 

0 

17.53 

276 

60 

40 

Fresh-cut. 

52.00 

1 

0 

9.06 

239 

60 

40 

Annealed. 

39.80 

17 

0 

14.10 

297 

65 

35 

Fresh-cut. 

52.00 

0 

1 

3.67 

290 

65 

35 

Annealed. 

33.00 

10 

0 

5.00 

335 

70 

30 

Fresh -cut. 

55.00 

0 

14 

3.45 

316 

70 

30 

Annealed. 

40.00 

7 

0 

4.67 

375 

72.5 

27.5 

Fresh-cut. 

55.00 

0 

42 

3.92 

275 

72.5 

27.5 

Annealed. 

45.00 

3 

0 

3.76 

362 

75 

25 

Fresh-cut. 

55.00 

0 

60 

5.64 

258 

75 

25 

Annealed. 

50.00 

0 

6 

5.40 

300 

Exhibit  of  Modified  Silver-Tin  Alloys. 


Formulse. 


Modifying  Metal. 


Gold  5 

Gold  5 

Platinum  5.  . 
Platinum  5.  . 
Copper  5. . . . 
Copper  5 . . . . 

Zinc  5 

Zinc  5 

Bismuth  5. . . 
Bismuth  5. . 
Cadmium  5. . 
Cadmium  5. , 

Lead  5 

Lead  5 

Aluminum  5 
Aluminum  1 
Aluminum  1 


Silver. 


35 

35 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

33.25 

34.5 

34.5 


How  prepared. 


Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Annealed. 
Fresh-cut. 
Fresh-cut. 
Annealed. 


tl-t 

1^ 

bo 

a 

'u 

_o 
ft 

0 

52.33 

0 

1 

3.67 

33.00 

10 

0 

5.00 

51.52 

0 

4 

3.35 

33.53 

7 

0 

5.06 

47.56 

0 

1 

4.62 

30.35 

7 

0 

6.07 

51.87 

0 

9 

9.68 

37.33 

7 

0 

8.20 

53.65 

0 

23 

2.38 

35.60 

5 

0 

3.50 

56.65 

0 

68 

1.83 

40.65 

0 

9 

2.07 

46.26 

0 

0 

4.78 

23.67 

6 

0 

5.58 

57.57 

0 

100 

6.40 

47.25 

0 

5 

3.54 

44.17 

0 

1 

4.88 

32.76 

10 

0 

7.18 

65.00 

0 

445 

46.98 

0 

166 

12.60 

38.26 

0 

48 

17.90 

290 
335 
329 
380 
330 
395 
273 
352 
343 
416 
290 
345 
288 
308 
225 
290 
290 
276 

198 
213 


their  rigidity,  for  certain  of  them  possess  great  resistance  to  fracture  of  the 
edges  or  angles,  and  still  under  the  stress  of  mastication  evince  a  decided 
tendency  to  flow,  and  consequently  to  a  disturbance  of  the  margins.  All 
are  therefore  more  or  less  unstable,  and  still  some  of  them  might  be  said 
to  possess  great  '' edge-strength"  when  iu  reality  they  possess  very  little. 
It  therefore  becomes  necessary  to  discard  or  to  modify  the  generally  ac- 


312  OPERATIVE   DENTISTRY. 

cepted  meaning  of  the  term  "  edge-strengtli"  to  make  it  harmonize  with 
the  new  data  regarding  the  flow  of  all  silver-tin  amalgams  under  stress. 

Those  amalgams  which  flow  least  have  also  the  highest  crushing  strength, 
as  will  be  seen  by  a  reference  to  the  above  tables.  The  most  stable  ''  un- 
modified silver-tin"  amalgam  contains  72.5  per  cent,  of  silver  and  27.5  per 
cent,  of  tin  ;  its  shrinkage  when  annealed  was  3  ;  expansion,  0  ;  flow,  3.76  ; 
crushing  stress,  362  pounds. 

The  most  staUe  modified  silver-tin  amalgams  are  those  which  contain 
gold  and  those  which  contain  copper. 

The  formula  of  the  former  is,  silver,  61.75  ;  tin,  33.25  ;  gold,  5.  Fresh- 
cut,  shrinkage,  0  ;  expansion,  1 ;  flow,  4.62  ;  crushing  stress,  330.  An- 
nealed, shrinkage,  7  ;  expansion,  0  ;  flow,  3.07  ;  crushing  stress,  395. 

The  formula  of  the  latter  is,  silver,  61.75  5  tin,  33.25;  copper,  5. 
Fresh-cut,  shrinkage,  0  ;  expansion,  23  ;  flow,  2.38  ;  crushing  stress,  343. 
Annealed,  shrinkage,  5;  expansion,  0;  flow,  3.50;  crushing  stress,  416. 

Color. — The  tendency  of  amalgam  to  discolor  upon  its  surface  through 
the  action  of  oxygen  and  sulphur  has  restricted  the  use  of  this  material 
to  those  portions  of  the  mouth  where  the  objectionable  color  would  not 
attract  attention.  Ever  since  the  early  efforts  of  Townsend  to  manufacture 
a  dental  alloy  that  would  not  discolor,  it  has  been  the  ambition  of  manu- 
facturers and  individual  experimenters  to  discover  a  formula  which  would 
produce  an  amalgam  that  would  maintain  its  color  under  all  conditions 
that  are  likely  to  be  met  in  the  mouth.  The  formula,  silver  61. 75,  tin 
33.25,  gold  5,  comes  nearest  to  making  an  amalgam  that  will  not  discolor. 
Flagg's  formula,  silver  58,  tin  37,  gold  5,  also  gives  excellent  results. 
The  writer  has  for  years  made  an  alloy  containing  silver  65,  tin  30,  gold 
5,  which  has  stood  the  clinical  test  of  twenty  years  without  discoloration, 
and  shows  as  good  margins  as  many  gold  fillings  which  have  done  service 
in  the  same  locations  for  a  like  period  of  time. 

The  discoloration  of  amalgam  is  not  confined  alone  to  the  exposed  sur- 
faces of  the  filling,  but  often  extends  to  the  surfaces  which  lie  against  the 
dentin,  causing  discoloration  of  that  tissue.  This  discoloration  of  the  den- 
tin occurs  most  frequently  under  fillings  which  shrink  or  have  been  im- 
properly introduced,  or  in  which  secondary  caries  is  progressing,  causing 
leakage. 

This  discoloration  may  be  shallow  or  deep  according  to  the  character  of 
the  composition  of  the  alloy,  and  is  due  to  the  formation  of  metallic  sul- 
phides, from  the  decomposition  of  albuminous  substances  and  the  genera- 
tion of  hydrogen  sulphide.  Black  discolorations  are  found  in  amalgams 
containing  silver  and  copper  ;  yellowish  stains  in  those  containing  cadmium. 

To  prevent  discoloration  of  the  dentin  many  operators  are  in  the  habit 
of  lining  the  cavity  with  zinc  oxyphosphate  cement,  or  other  barrier,  before 
introducing  the  amalgam. 

Conductivity. — Amalgam  as  a  conductor  of  heat  and  cold  stands  mid- 
way between  gold  and  the  basic  zinc  cements  in  the  scale  of  the  filling- 
materials.     As  a  conductor  of  electric  currents  it  stands  next  below  gold. 

On  account  of  the  fact  that  amalgam  is  often  used  to  fill  cavities  which 
are  very  large  and  dangerously  near  to  the  pulp,  this  organ  should  be  pro- 


PLASTIC    FILLING-MATERIALS.  313 

tected  from  the  dangers  of  thermal  shock  by  the  interposition  of  some  low- 
conducting  filling-material,  like  zinc  oxyphosphate  cement  or  gutta-percha. 

Galvanic  shock  is  sometimes  experienced  when  some  other  metal  having 
a  higher  or  lower  potential  than  the  amalgam  filling  comes  in  contact  with 
it,  as,  for  instance,  a  gold  filling  in  an  opposite  tooth  when  contact  is  made 
and  broken  during  mastication,  or  when  a  table  fork  touches  it. 

As  soon  as  the  external  surface  of  the  filling  becomes  discolored  gal- 
vanic shock  ceases.  This  is  due  to  the  iuteri^osition  of  the  metallic  sul- 
phides, which  are  non-conductors  of  electric  currents. 

Chemical  Relations. — It  has  never  been  positively  demonstrated  that 
amalgam  exercises  any  si^ecific  therapeutic  influence  ui)on  the  dentin, 
although  clinical  evidence  is  abundant  that  such  is  the  fact  with  those  that 
contain  copper.  Miller,  in  experimenting  with  the  various  plastic  filling- 
materials,  as  to  their  antiseptic  properties  and  their  retarding  influence 
upon  the  growth  of  mouth  bacteria,  found  that  copper  amalgam  was  the 
only  one  which  possesses  such  qualities,  and  that  it  invariably  manifested 
a  retarding  or  preventive  action  upon  the  growth  of  bacteria.  Fig.  448 
shows  this  action  upon  a  gelatin  plate. 

Fig.  448. 


An  inoculated  gelatin  plate  containing  :  a,  pieces  of  oxyphospliate  cement  one  day  old ;  6, 
pieces  of  gold  amalgam  one  day  old  ;  c,  pieces  of  an  old  copper  amalgam  filling,  age  unknown ;  d, 
pieces  of  stained  dentin  from  a  tooth  wliich  had  been  filled  many  years  previously  with  copper  amal- 
gam.    (Miller.) 

Weagant,  in  writing  uj^ou  this  subject,  says,  "Instead  of  having  any 
injurious  effect  upon  the  teeth  or  surrounding  tissues,  it  is  decidedly  bene- 
ficial to  them,  acting  as  an  antiseptic  or  germ  destroyer.'''' 

Fletcher  also  maintains  the  same  view. 

According  to  Tomes,  the  sulphide  of  copper  formed  by  the  action  of  the 
hydrogen  sulphide  of  the  mouth  upon  the  coj)per  of  the  amalgam  is 
readily  converted,  on  exposure  to  air  and  moisture,  into  copper  sulphate ; 
hence  it  is  almost  certain  that  the  latter  is  formed  upon  the  exposed  sur- 
face of  the  filling.  Cupric  sulphate  is  freely  soluble,  and  therefore  is  likely 
to  xiermeate  the  dentin  by  following  the  tubuli.  Sulphides  of  the  other 
metals  are  not  so  readily  converted  into  soluble  salts,  and  therefore  do  not 
penetrate  the  dentin  so  freely. 


314 


OPERATIVE    DENTISTRY. 


Flagg  believes  there  is  a  gradual  formation  of  soluble  salts  of  silver, 
tin,  and  copper,— these  metals  forming  the  usual  constituents  of  dental 
alloys,— which  being  dissolved  are  taken  up  by  the  contiguous  dentin,  thus 
changing  the  relations  existing  between  the  filling  and  the  dentin,  and  ren- 
dering them  more  in  harmony  with  each  other  (''  compatible"),  and,  '^ivith 
its  incorporated  metallic  salts,  becomes  so  in  affinity  with  the  amalgam  filling 
as  to  insure  almost  completely  harmonious  apposition  of  tooth  bone  and 
filling,  cessation,  practically,  of  decay,  and  recalcification  (?)  with  metallic 
lustre  of  decalcified  dentin." 

Cadmium  amalgam  and  amalgams  which  contain  cadmium  gradually 
softeu  and  disintegrate,  and  if  the  cadmium  is  present  in  large  quantity, 
the  dentin  becomes  decalcified  and  stained  a  bright  orange-yellow  from  the 
formation  of  cadmium  sulphide. 

Dental  amalgams,  as  a  class,  are,  however,  chemically,  practically  in- 
soluble in  the  secretions  of  the  mouth.  Lactic  acid  and  the  other  less 
common  solvent  agents  found  in  the  mouth  have  little  or  no  effect  upon 
them. 

COMPOSITION   OF    ALLOYS. 

The  metals  which  are  used  in  the  manufacture  of  dental  alloys  are 
antimony,  aluminum,  bismuth,  cadmium,  copper,  gold,  platinum,  palla- 
dium, and  zinc. 

The  following  condensed  table  gives  the  composition  of  a  few  of  the 
best-known  dental  alloys. 


H 

0) 

> 

CO 

'6 

a 

a 

p. 
o 

o 

6 

a 

a 
o 

< 

51.52 

51.90 

57.5 

50.35 

37 

85 

35 

49.27 

40.60 

40 

40 

50 

48.48 

46 

42.5 

43.35 

58 

60 

60 

48.24 

52 

40 

50 

50 

1.70 

.40 

3.35 
5 

1.30 

1.65 

5 

5 

0.05 
4.40 
20 

3 
2.44 

3 

10 

Chase's  plastic  tin 

7 

Antimony.  (Stibium.  Symbol,  Sb.  Fuses  at  840°  F.) — This  metal  has 
but  little  place  in  the  manufacture  of  dental  alloys.  It  is  still  used,  how- 
ever, in  a  few  of  the  alloys  offered  for  sale,  sometimes  in  large  quantities. 

Amalgams  containing  antimony  in  considerable  quantity  are  notably 
fine  grained,  very  plastic,  and  do  not  shrink,  but  are  exceedingly  dirty  to 
work. 

Small  quantities  of  antimony  added  to  silver-tin  alloys, — tin  in  excess, 
— it  is  claimed,  control  the  shrinkage. 

Aluminum.  {Aluminum.  Symbol,  Al.  Fusing-point,  1292°  F.) — This 
is  the  lightest  of  the  known  metals,  its  specific  gravity  being  2.50  to  2.67. 
When  alloyed  with  silver  and  copper  it  gives  a  non-tarnishing  and  uon- 


PLASTIC   FILLING-MATERIALS.  315 

corrosive  quality  to  these  metals  and  greatly  increases  their  tensile 
strength .     (Mitchell. ) 

Aluminum  has  been  used  as  a  constituent  of  dental  alloys  for  the  pur- 
pose of  controlling  the  color  and  imparting  greater  tensile  strength,  but  it 
destroys  the  integrity  of  the  amalgam.  Black  found  that  the  addition  of 
five  per  cent,  of  aluminum  to  sixty-five  of  silver,  and  thirty-five  of  tin 
formed  an  alloy  that  when  mixed  with  mercury  ^'amalgamated  nicely, 
forming  a  very  white,  soft  mass,  but  it  soon  became  too  hot  to  handle." 
The  thermometer  indicated  186°  F.  The  setting  was  also  attended  with 
the  formation  of  considerable  heat  and  enormous  expansion,  and  later 
disintegration  of  the  mass  took  place,  resulting  in  the  formation  of  a  dark 
powder  which  would  cohere  a  little  on  being  pressed  together. 

Disintegration  did  not  take  place  when  the  mass  was  rapidly  worked 
and  packed  in  glass  tubes,  but  the  tubes  soon  became  too  hot  to  handle. 
A  remarkable  phenomenon  is  observed  during  the  combining  of  the  alloy 
with  the  mercury, — viz.,  the  evolution  of  gas,  which  gave  otf  a  distinct 
crepitating  sound  from  the  bursting  gas-bubbles.  The  instruments  used  in 
packing  the  amalgam  were  darkened  and  corroded. 

The  expansion  of  the  material  seems  to  be  almost  continuous,  for  Black 
states  "that  in  twenty-four  hours  an  expansion  of  one  hundred  and  twenty 
points  had  occurred,  as  indicated  by  the  micrometer ;  at  the  end  of  the 
second  day  the  expansion  reached  one  hundred  and  eighty-one  points  ;  and 
at  the  end  of  the  third  day  two  hundred  and  seventeen  points,  and  though 
diminishing  it  did  not  stop.  At  the  end  of  forty-three  days  it  had  reached 
the  enormous  figure  of  four  hundred  and  forty-five  points  of  expansion, 
when  it  passed  beyond  the  capacity  of  the  micrometer  to  register. 

"Annealing  the  alloys  at  130°  F.  controlled  the  expansion  somewhat, — 
it  was  stationary  from  the  second  day  to  about  the  fifth  day,  when  it  again 
began,  slowly,  and  continued  for  about  forty  days." 

Aluminum,  therefore,  should  have  no  place  as  a  constituent  of  dental 
alloys,  as  its  use  not  only  destroys  the  value  of  the  metals  with  which  it  is 
combined,  but  the  added  danger  is  to  be  considered  of  fracturing  or  burst- 
ing the  thin  walls  of  the  cavity  by  the  enormous  expansion  which  takes 
place  during  the  process  of  setting  and  afterwards. 

Bismuth.  (Bisnmthum.  Symbol,  Bi.  Fusing-point,  507°  F.) — This 
metal  has  been  used  in  dental  alloys  to  control  the  shrinkage  in  the  low- 
grade  silver-tin  alloys,  in  which  the  tin  is  largely  in  excess  of  the  silver, 
as  it  expands  very  considerably  on  cooling. 

Alloys  containing  bismuth  amalgamate  with  great  readiness  and  with  less 
mercury.     Amalgams  made  from  alloys  containing  bismuth  are  very  dark. 

Dr.  Black  found  the  expansion-shrinkage  range  reduced  in  those  amal- 
gams which  contained  it,  but  the  flow  was  increased. 

Cadmium.  {Cadmium.  Symbol,  Cd.  Fusing-point,  442°  F.)— The  use 
of  alloys  containing  cadmium  was  first  suggested  nearly  fifty  years  ago  by 
the  late  Dr.  Evans,  of  Paris.  It  was  claimed  for  this  metal  that  it  amal- 
gamated readily,  that  it  did  not  discolor,  and  that  it  set  very  raj)idly,  and 
made  a  durable  filling.  The  hoj^es  raised  by  these  claims  were  soon  dissi- 
pated, however,  for  gradual  softening  and  disintegration  of  the  mass  took 


316  OPERATIVE    DENTISTRY. 

place,  tlie  dentin  was  decalcified  and  stained  a  bright  orange-yellow  -,  but 
worst  of  all,  the  pulps  of  many  of  the  teeth,  filled  with  this  material 
were  (knitalized  from  the  poisonous— irritating— effect  of  the  cadmium 
sulphide,  and  which  is  stained  yellow  by  the  action  of  sulphuretted 
hydrogen.  Cadmium  is  still  used  as  an  occasional  component  of  dental 
alloys,  being  introduced  in  the  proportion  of  from  one  to  three  per  cent. 
It  is  claimed  by  those  using  it  that  it  causes  more  ready  amalgamation, 
controls  discoloration,  and  increases  the  rapidity  of  the  process  of  setting. 
Even  this  small  quantity,  nevertheless,  would  seem  to  be  out  of  place,  for 
all  of  the  above  advantages  can  be  obtained  by  more  satisfactory  and  less 
objectionable  means. 

Dr.  Black  found  ^'by  the  addition  of  five  per  cent,  of  cadmium  to  61.75 
per  cent,  of  silver  and  33.25  of  tin  that  it  greatly  increased  the  expansion 
of  the  amalgam  ;  that  it  requires  a  large  amount  of  mercury  to  amalgamate 
it ;  that  it  sets  very  quickly,  and  makes  very  white  and  beautiful-looking 
fillings. 

'  ^  The  expansion  of  the  unannealed  alloy  was  one  hundred  points  in  five 
days.  Annealing  largely  controlled  the  expansion,  reducing  it  to  five 
points.  In  the  expansion,  the  mass,  if  the  walls  of  the  cavity  are  smooth, 
slips  squarely  up  and  remains  flat  upon  the  top. 

"The  flow  in  the  unannealed  alloy  was  6.40;  in  the  annealed,  3.54. 
The  crushing  strength  was  increased  by  annealing  from  two  hundred 
and  twenty-five  to  two  hundred  and  ninety  pounds." 

Copper.  (Cuprum.  Symbol,  Cu.  Fusing- j)oint,  1996°  F.) — This  metal 
in  small  quantities  enters  into  the  composition  of  all  of  the  better  class  of 
dental  alloys.  An  addition  of  five  per  cent,  to  the  silver-tin  alloys — 
tin  in  excess — increases  the  rapidity  with  which  it  sets,  controls  the 
shrinkage,  gives  a  white  color  to  the  amalgam,  increases  its  hardness, 
and  exerts — by  reason  of  the  formation  of  sulphide  of  copper,  which 
on  becoming  oxidized  forms  the  sulphate — an  antiseptic  action  upon 
the  dentin. 

Dr.  Black  found  that  five  per  cent,  of  copper  added  to  the  61.75  of 
silver  and  33.35  of  tin  alloy  caused  the  unannealed  alloy  to  set  very 
quickly.     When  annealed  it  set  as  slowly  as  the  unmodified  alloy. 

The  expansion  and  the  expansion- shrinkage  range  was  greatly  in- 
creased, the  flow  was  diminished,  and  the  crushing  stress  was  raised 
to  the  highest  in  the  series. 

Copper  Amalgam. — This  substance  is  a  combination  of  pure  copper 
and  mercury  in  varying  quantities,  and  is  therefore  a  binary  amalgam.  It 
is  made  by  several  processes  : 

(1)  By  adding  freshly  precipitated  and  washed  metallic  copper  to  an 
excess  of  mercury  ;  as  soon  as  solution  of  the  cop]3er  is  complete,  the  sur- 
plus mercury  should  be  expressed  by  wringing  the  mass  in  a  piece  of 
chamois-skin.  The  plastic  material  remaining  should  then  be  formed  into 
small  tablets  by  pressing  in  suitable  moulds  ;  when  hardened  it  is  ready 
for  future  use. 

Eollins,  Ames,  and  others  have  published  methods  for  making  it  by 
electrolysis. 


PLASTIC    FILLING-MATERIALS.  317 

(2)  Eollins's  metliod  is  as  follows  : 

Distilled  water,  five  gallons  ;  sulphate  of  copper,  enough  to  saturate ; 
sulphuric  acid,  one  pound.  Mix,  filter,  and  pour  into  a  wooden  firkin 
with  wooden  hooi)s.  All  of  the  chemicals  should  be  absolutely  pure. 
Place  ten  pounds  of  pure  mercury  in  a  glass  jar  and  immerse  in  the  copper 
solution.  To  the  zinc  plate  of  a  galvanic  battery  attach  a  gutta-percha- 
covered  wire,  having  one  end  bare  for  about  an  inch.  This  exposed  end 
is  to  be  immersed  below  the  level  of  the  surface  of  the  mercury.  Tie 
granulated  pure  copper  in  a  bag  and  hang  it  in  the  copper  solution,  con- 
necting with  a  wire  to  the  carbon  of  the  battery.  The  battery  is  to  be 
kexDt  in  action  till  the  mercury  has  absorbed  enough  copper  to  make  a 
thick  paste.  Then  remove  and  wash  thoroughly  in  hot  water  till  all  of  the 
sulphate  solution  has  been  removed.  Squeeze  out  the  softer  amalgam  and 
allow  the  remainder  to  harden  ;  heat  it  and  renew  the  squeezing  as  before. 
This  method  insures  an  amalgam  of  perfect  purity,  and  is  simpler  than  any 
of  the  old  and  faulty  methods  in  use. 

(3)  Chandler  suggested  another  method  of  making  copper  amalgam, 
which  is  as  follows  : 

To  a  hot  solution  of  sulphate  of  copper  add  a  little  hydrochloric  acid 
and  a  few  sticks  of  zinc,  and  boil  for  about  a  minute.  The  copper  will  be 
precipitated  in  a  spongy  mass.  Take  out  the  zinc,  pour  off  the  liquid,  and 
wash  the  copper  thoroughly  with  hot  water.  Pour  on  the  mass  a  little  dilute 
nitrate  of  mercury,  which  will  instantly  cover  every  particle  of  copper 
with  a  coating  of  the  mercury.  Add  mercury  two  or  three  times  the 
weight  of  the  copper,  triturate  slightly  in  a  mortar,  and  finish  by  heating 
the  mixture  a  few  minutes  in  a  crucible. 

Copper  amalgam  is  prepared  for  introduction  into  the  cavity  of  a  tooth  by 
heating  one  of  the  prepared  and  hardened  tablets,  crushing  and  grinding 
it  in  a -mortar,  when  it  again  becomes  plastic.  It  may  be  made  to  set 
quickly  or  slowly  as  desired  by  squeezing  out  a  portion  of  the  mercury  or 
by  adding  to  it.  On  setting  it  becomes  very  hard, — in  fact,  it  is  the  hardest 
of  all  the  dental  amalgams.  It  neither  shrinks  nor  expands,  retains  good 
margins,  and  when  properly  made  does  not  waste  in  the  mouth.  Its  most 
objectionable  feature  is  the  black  discoloration  of  its  surface  ;  but  this 
does  not  ajjpear  so  objectionable  if  the  surfaces  of  the  fillings  have  been 
nicely  polished,  for  then  the  surface  has  a  black  polish  instead  of  the 
rough,  dirty  black  color  that  prevails  if  the  surfaces  are  left  in  a  rough 
state. 

This  material  has  no  equal  for  filling  the  posterior  teeth  of  children 
under  twelve  years  of  age,  where  antiseptic  qualities  are  needed.  Its 
greatest  value,  however,  lies  in  its  use  in  the  deciduous  molars  of  little 
children  for  whom  rapid  operations  are  a  necessity. 

Copper  amalgam  was  the  only  alloy  tested  by  Dr.  Black  which  did 
not  flow  under  stress.  It  suffers  no  change  of  form  under  stress,  except  to 
crush  into  fragments.  It  is  as  rigid  and  unyielding  within  the  limits  of  its 
strength  as  a  piece  of  hardened  steel,  and  can  neither  be  bent  nor  com- 
pressed. I^o  shrinkage  during  setting  could  be  discovered.  A  very  slight 
expansion  was  always  present,  but  it  was  so  slight  as  to  be  of  no  impor- 


318  OPERATIVE    DENTISTRY. 

tance.  In  the  large  majority  of  the  fillings  which  he  tested  it  did  not  ex- 
ceed TuouTT  of  an  inch. 

When  it  is  once  adapted  to  the  walls  of  the  cavity  and  hardened  the 
adaptation  is  permanent,  for  it  can  suffer  no  change  of  form  from  the  stress 
of  mastication.  These  physical  properties  of  copper  amalgam  give  it 
permanence,  and  according  to  the  opinion  of  Dr.  Black,  explain  the  power 
of  the  material  to  arrest  caries  rather  than  any  chemical  or  disinfectant 
property  of  the  copper  or  of  its  salts. 

Copper  amalgam  fillings,  when  well  placed  in  properly  prepared  cavi- 
ties, retain  their  perfect  margins,  and  do  not  discolor  the  tooth -structure  ; 
and  but  for  the  wasting  which  sometimes  occurs  at  the  exposed  surface 
and  its  dark  color,  this  material  would  be  the  most  satisfactory  of  all  of 
the  amalgams. 

Gold.  (Aurum.  Symbol,  Au.  Fusing-point,  2016°  F.) — This  metal 
during  late  years  has  become,  in  small  quantities,  a  quite  common  com- 
ponent of  most  of  the  high  grade  dental  alloys.  It  enters  into  these  alloys 
in  the  proportion  of  from  three  to  five  per  cent.  Experiment  has  demon- 
strated that  more  than  any  other  metal  used,  in  proportion  to  the  small 
amount  required,  except  copper,  it  diminishes  shrinkage,  increases  the 
rapidity  of  setting,  controls  the  color,  adds  to  its  crushing  strength,  and 
imparts  fine  grain  while  in  the  plastic  state.  The  addition  of  from  five  to 
seven  per  cent  of  gold  to  the  silver- tin  alloys — silver  in  excess — gives  the 
best  results. 

According  to  Dr.  Black,  the  addition  of  five  per  cent,  of  gold  seems  to 
give  a  little  softer  working  property  to  the  amalgam  and  slows  the  setting. 

Annealing  increases  the  soft  working  property.  It  requires  a  little  less 
mercury  than  the  unmodified  alloy,  and  the  flow  was  slightly  increased. 
This  amalgam  is  very  tough  and  bears  a  heavy  crushing  stress  before  break- 
ing, and  it  controls  the  shrinkage-expansion  range,  three  points.    • 

Palladium.  (Palladium.  Symbol,  Pd.  Fusing-point,  a  little  below  that 
of  platinum,  about  3500°  F.,  but  requires  the  oxyhydrogen  blow-pipe  to  fuse 
it.) — ^Palladium  in  combination  with  mercury  forms  a  compound  or  binary 
amalgam,  which  has  been  recommended  for  use  in  the  posterior  teeth  of 
children.  It  is  made  by  combining  palladium  with  three  times  its  weight 
of  mercury.  Palladium  is  precipitated  from  a  solution  of  its  chloride  by 
iron  or  zinc  washed  in  nitric  acid  and  dried.  To  this  precipitate  the 
mercury  is  added.  Care  is  necessary  in  the  mixing,  as  palladium  forms  a 
true  chemical  compound  with  mercury,  and  the  action  is  so  intense  and 
the  evolution  of  the  heat  so  great  that  under  certain  circumstances  an  ex- 
plosion might  take  place.  Palladium  amalgam  turns  black  upon  the  ex- 
ternal surface,  but  it  does  not  discolor  the  dentin.  It  sets  so  rapidly  that 
unless  it  is  mixed  very  soft  it  becomes  hard  before  it  can  be  introduced 
into  iihe  cavity,  consequently  it  should  be  worked  rapidly  and  with  warm 
instruments.  Chandler  found  that  the  adding  of  a  large  proportion  of  gold 
rendered  the  palladium  amalgam  more  tractable. 

It  has  no  good  qualities  which  are  not  possessed  m  a  higher  degree  by 
copper  amalgam.  The  only  thing  in  its  favor  is  its  name,  as  it  is  one  of 
the  precious  metals. 


PLASTIC    FILLING-MATERIALS.  319 

Platinum.  (Platirmm.  Symbol,  Pt.  Fusing-point,  above  3500°  F.,  and 
requires  the  oxyhydrogen  blowpipe.)— According  to  Essig,  platinum  is 
only  of  value  in  an  amalgam  when  combined  with  tin,  silver,  and  gold 
in  a  proper  proportion  of  mercury.  Fletcher  claims  that  the  addition  of 
a  small  quantity  of  platinum  to  a  three-metal  alloy,  forty  silver,  sixty  tin, 
ten  gold,  causes  it  to  set  quicklj^ 

Flagg  looks  upon  platinum  as  having  no  value  in  a  dental  alloy  over 
the  same  equivalent  of  tin,  and  therefore  valueless  as  a  component  of  amal- 
gams for  filling  teeth. 

Black  found  by  adding  five  per  cent,  of  platinum  to  the  silver-tin  alloy 
it  made  a  dirty  working  amalgam,  which  blackened  the  hands,  set  slowly, 
flowed  badly,  and  increased  the  shrinkage-expansion  range. 

Silver.  {Argentum.  Symbol,  Ag.  Fusing-point,  1873°  F.)— This  is  the 
most  valuable  and  important  of  all  the  metals  which  enter  into  the  compo- 
sition of  dental  alloys.  In  the  superior  grades  of  alloys  it  forms  the  largest 
portion,  while  in  the  inferior  grades  tin  holds  the  first  place. 

Silver  is  essential  to  the  proper  setting  of  an  amalgam.  Alloys  in 
which  silver  predominates  set  much  more  rapidly  than  those  in  which  tin 
forms  the  largest  proportion. 

Alloys  containing  a  large  proportion  of  silver  expand,  while  those  com- 
posed largely  of  tin  shrink.  When  silver  and  tin  are  united  in  the  proper 
proportions  they  will  make  an  amalgam  having  the  lowest  shrinkage- 
expansion  range  possible  with  any  other  known  metals,  except  copper 
amalgams.  This  formula  has  been  demonstrated  by  Dr.  Black  to  be,  sil- 
ver, 65  ;  tin,  35  ;  which  gave  shrinkage,  0  ;  expansion,  1. 

Tin.  {Stannum.  Symbol,  Sn.  Fusing-point,  442°  F.)— This  metal  oc- 
cupies the  next  most  important  place  to  silver  as  a  component  of  dental 
alloys.  It  shrinks  in  cooling  more  than  any  of  the  other  metals  which  enter 
into  these  compounds.  Amalgams  which  contain  an  excess  of  tin  shrink 
badly,  set  slowly,  and  lack  hardness.  These  objectionable  features  are 
overcome  by  combining  it  with  silver  or  with  silver  and  copper  or  silver 
and  gold.  The  advantages  of  tin  in  a  dental  alloy  are  that  it  facilitates 
amalgamation,  aids  in  producing  a  good  color,  and  reduces  conductivity. 

Zinc.  (Zincum.  Symbol,  Zn.  Fusing-point,  773°  F.)— This  metal  in 
combination  with  copper  formed  one  of  the  most  ancient  alloys  of  which 
there  is  any  record.  When  added  to  dental  alloys  in  which  tin  predomi- 
nates in  large  quantity,  in  the  amount  of  one  to  one  and  one-half  per  cent, 
it  completely  controls  the  shrinkage,  adds  a  satisfactory  whiteness  to  the 
filling,  and  prevents  discoloration.     (Flagg.) 

Black  found  the  addition  of  five  per  cent,  to  the  61.75  silver,  33.25  tin, 
formula  greatly  hastened  the  setting,  and  that  it  required  more  mercury 
for  amalgamation  ;  but  that  the  flow  was  decidedly  decreased,  the  expan- 
sion range  increased,  and  the  crushing  strength  above  the  average. 

MAKING  DENTAL  ALLOYS. 

The  rational  method  of  making  dental  alloys  is  to  melt  that  metal  first 
which  fuses  at  the  lowest  degree  of  heat.  Tin,  which  forms  a  considerable 
part  of  all  dental  alloys,  fuses  at  442°  F.     This  is  the  lowest  fusing  metal 


320  OPERATIVE    DENTISTRY. 

that  enters  into  their  composition,  and  should  therefore  be  melted  first, 
and  tlie  other  higher  fusing  metals  added  in  the  order  of  their  fasing-point, 
as,  for  instance,  in  a  binary  alloy  the  silver,  which  melts  at  1875°  F., 
should  be  added  to  the  melted  tin  ;  in  a  ternary  alloy  the  copper,  which 
fuses  at  1996°  F.,  should  be  added  after  the  silver  5  and  in  a  quarternary 
alloy  the  gold,  which  fuses  at  2016°  F.,  should  be  added  after  the  copper,  etc. 

The  object  of  thus  reversing  the  old  method  was  to  prevent  the  volatili- 
zation of  the  tin  and  thereby  secure  a  definite  compound,  which  was  not 
the  case  when  the  tin  was  heated  to  more  than  2000°  F.,  as  volatilization 
immediately  takes  place  and  an  indefinite  compound  is  the  result. 

The  practitioner  who  would  make  his  own  alloys  should  provide  him- 
self with  a  good  Hessian  or  sand  crucible,  holding  ten  or  twelve  ounces 
liquid  measure,  a  pair  of  crucible  tongs,  and  a  quantity  of  borax  to  be 
used  as  a  flux. 

Tin  may  be  obtained  at  any  hardware  shop  in  the  form  of  bars  or 
ingots.     Banca  tin  is  the  best,  as  being  most  free  from  impurities. 

Silve7^  can  be  obtained  of  any  silversmith.  Granulated  silver  is  the 
best  for  the  purpose,  as  it  is  divided  into  small  beads  or  granules,  and  is 
therefore  dissolved  more  rapidly  in  the  melted  tin  than  larger  pieces 
would  be. 

Copper  can  also  be  obtained  at  the  hardware  shop.  Soft  copper  wire  is 
the  best  form  in  which  to  buy  it.  This  should  be  cut  into  very  small 
pieces,  about  one-eighth  of  an  inch  in  length. 

Gold  in  the  form  of  foil  scraps  is  always  on  hand  in  the  office  of  every 
dentist. 

The  other  metals  which  sometimes  enter  into  the  composition  of  dental 
alloys  are  easily  obtained,  if  it  is  desired  to  experiment  with  them  ;  but 
tin,  silver,  copper,  and  gold  are  the  only  metals  that  are  used  in  a  really 
first-class  alloy. 

Flagg,  in  describing  a  "melt,"  says  the  crucible  should  contain  a  liberal 
amount  of  borax,  which  should  be  melted  first,  filling  it  about  one-third 
full.  "  This  is  intended  for  a  '  flux.'  An  ordinary  coke  or  coal  fire  is  all 
that  is  required  for  the  '  melt ;'  but  it  is,  of  course,  more  systematically 
and  perhaps  more  readily  done  in  the  usual  dental  or  smelting  forge-fire. 

''  Having  perfectly  fused  the  borax,  in  it  the  tin  is  melted  first,  requiring 
but  a  low  temperature,  and  after  it  is  melted  the  granulated  silver  is  added. 
These  two  metals  are  thoroughly  stirred  together  with  an  iron  rod  or  clay 
pipe-stem  of  suitable  size  and  length,  and  when  completely  incorporated 
the  copper — small  pieces  of  wire — is  added.  This,  like  the  silver,  is  soon 
melted,  and  may  be  equally  homogeneously  mixed.  Lastly  the  gold  is  added, 
melted,  and  all  is  thoroughly  stirred  together  with  the  iron  rod  or  pipe-stem. 

''When  perfectly  melted  and  mixed,  the  fused  mass  should  be  quickly 
poured  into  a  broad,  open,  flat,  shallow  matrix  made  of  iron  or  soapstone  : 
this  favors  prompt  cooling,  and  thus  secures  the  greatest  uniformity  of 
distribution  to  the  components." 

After  the  ingot  has  cooled  it  can  be  reduced  to  fine  grains  or  coarse 
powder  by  filing,  or  the  ingots  may  be  cast  in  round  bars  or  rods,  and 
reduced  to  fine  shavings  by  turning  in  a  lathe. 


CHAPTEE    XX. 

MANIPULATION   AND   INTRODUCTION   OF   PLASTIC   FILLING-MATEEIALS. 

Amalgam  is  generally  used  under  those  conditions  and  circumstances 
in  whicli  a  permanent  filling  is  desired,  but  in  which  gold  or  tin  and 
their  combinations  are  inadmissible,  either  from  the  inaccessibility  of  the 
cavity,  the  frail  condition  of  the  tooth,  the  physical  state  of  the  patient, 
forbidding  the  nervous  strain  of  long  and  tedious  gold  operations,  or  the 
inability  of  the  individual  to  i)ay  for  such  expensive  service.  Under  no 
conditions,  however,  should  amalgam  be  used  in  the  anterior  teeth.  It 
may  be  used  in  some  cases  upon  the  distal  surface  of  the  first  bicuspids, 
but  never  in  a  more  anterior  position.  If  the  conditions  require  the  use 
of  plastics  in  the  anterior  teeth,  the  oxyphosphate  cements  and  gutta- 
percha are  the  best  for  this  purpose. 

Crutta-percha  in  the  form  of  Hill's  stopping  is  the  most  reliable  of  the 
plastics  that  are  admissible  in  the  anterior  teeth. 

Amalgams,  however,  are  not  used  to  the  same  extent  as  they  once 
were ;  for  many  teeth  that  were  formerly  restored  to  normal  contour  by 
extensive  oi)erations  with  amalgam  can  now,  since  the  introduction  of  the 
more  advanced  methods  of  crowning,  be  better  and  more  permanently 
treated  by  these  methods. 

Various  combinations  of  filling- materials  have  also  been  resorted  to,  in 
order  to  limit  the  uses  of  amalgam  as  far  as  possible  to  those  positions  in 
which  they  would  be  unobserved,  to  prevent  discoloration  of  the  tooth 
substance,  or  to  give  added  beauty,  strength,  and  durability  to  such  fill- 
ings as  were  subjected  to  great  stress ;  as,  for  instance,  in  compound  cavi- 
ties in  the  bicuspids  and  molars,  when  the  cervical  portion  of  a  filling  is 
made  of  amalgam  and  the  morsal  portion  of  gold. 

The  preparation  of  cavities  for  the  reception  of  amalgams  requires 
the  same  care  and  thoroughness  in  all  of  its  details  as  would  be  observed 
in  preparing  them  for  gold  fillings,  the  only  difference  being  that  retain- 
ing grooves  and  pits  are  not  necessary  to  aid-  in  the  permanent  anchorage 
of  the  filling,  nor  for  starting  it.  If  a  general  retentive  form  is  given  to 
the  cavity,  that  is  all  that  will  be  required  to  prevent  its  dislodgement 
under  stress.  Temporary  separations  are  an  essential  preliminary  step  in 
the  preparation  of  approximal  cavities  and  in  the  restoration  of  contour 
in  these  locations. 

The  Especial  Uses  of  Amalgam. — 1.  Amalgam  is  especially  indi- 
cated in  that  class  of  cavities  in  which  the  cervical  margin  lies  at  some 
distance  beneath  the  border  of  the  gum,  making  it  impossible  from  its 
inaccessibility  and  the  difficulties  in  excluding  moisture  to  successfully 
introduce  gold. 

2.  In  large  distal  cavities  in  the  second  and  third  molars,  where,  by 

21  321 


322 


OPERATIVE    DENTISTRY. 


reason  of  their  location,  their  size  and  frail  walls,  or  the  physical  condi- 
tion of  the  patient,  gold  fillings  could  not  be  satisfactorily  placed. 

3.  In  large  buccal  cavities  in  the  molars,  which  extend  to  the  gum  line 
or  beneatli. 

4.  In  large  approximal  cavities  in  bicuspids  and  molars. 

5.  In  large  morsal  cavities  in  the  molars. 

6.  In  compound  cavities  involving  the  mesial,  distal,  buccal,  or  lingual 
surfoces  united  with  the  morsal. 

The  last  four  classes  of  cavities  can,  of  course,  be  successfully  filled  with 
gold,  and  usually  with  better  results,  than  with  amalgam  ;  but  conditions 
and  circumstances  are  often  presented  in  which  the  operator  is  obliged  to 
choose  amalgam  to  the  exclusion  of  the  better  material. 

The  exclusion  of  moisture  is  as  essential  in  the  preparation  and  steriliza- 
tion of  cavities  to  receive  amalgam  as  when  gold  is  to  be  used,  and  the 
rubber  dam  should  be  adjusted  for  this  purpose  whenever  and  wherever  it 
is  possible  to  do  so.  Because  amalgam  is  a  cheaper  material,  and  requires 
less  skill  to  manipulate  it  than  gold,  is  no  reason  why  its  introduction 
should  be  less  carefully  and  conscientiously  performed,  or  less  pains  taken 
with  the  finishing  of  such  a  filling,  than  would  be  expended  upon  it  if  it 
were  gold.  Better  results,  no  doubt,  would  be  obtained  in  the  use  of  amal- 
gam if  a  higher  degree  of  care  in  details  were  expended  upon  it. 

The  employment  of  matrices  is  often  a  necessity  in  filling  large  compound 
cavities  in  the  molars  when  it  is  desired  to  restore  the  contour  of  the  in- 

FiG.  449. 


B 


Creager  loop  matrices. 


volved  surfaces.  In  these  cases  the  band  matrix  is  the  most  serviceable, 
and  to  obtain  the  best  results  from  its  employment  it  should  be  permitted 
to  remain  until  the  amalgam  has  set  sufficiently  hard  to  allow  it  to  be 
dressed  to  the  desired  form  and  polished. 

The  ordinary  loop  matrix  (Fig.  449)  and  the  Guilford  and  Brophy 
matrices  are  not  adapted  to  be  left  in  the  mouth  by  reason  of  their  screw 
mechanism  being  in  the  way  of  the  cheek. 

Dr.  Herbst's  method  of  forming  a  matrix  to  suit  each  individual  case  is 
admissible  in  this  class  of  cases,  for  the  reason  that  they  are  made  in  a 
moment,  and  can  be  so  shaped  that  they  will  not  injure  the  gum  or  the 
cheek,  or  interfere  with  the  occlusion  of  the  teeth  ;  consequently  they  may 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      323 

be  permitted  to  remain  upon  the  tooth  for  several  days  if  desired.  They 
are  made  as  follows  :  A  strip  of  German  silver,  No.  33  gauge,  is  cut  of  such 
width  as  will  reach  from  the  gum  to  the  morsal  surface  of  the  tooth,  and 
of  sufficient  length  to  embrace  it  and  have  about  one-fourth  of  an  inch  to 
spare.  This  strip  is  then  passed  around  the  tooth,  and  the  ends  grasped 
with  a  pair  of  Herbst  pliers — any  flat  nose  pliers  will  answer  the  purpose, 
however — and  drawn  tightly  around  the  tooth  by  pinching  the  ends  to- 
gether. A  close  adaptation  of  the  band  to  the  tooth  is  thus  secured. 
AVhile  still  holding  the  ends  of  the  band  with  the  pliers  it  is  removed 
from  the  tooth,  and  the  ends  soldered  together  over  an  alcohol  flame  or  a 
Bunsen  burner  with  tinner's  solder.  The  matrix  is  then  replaced  upon 
the  tooth,  and  if  it  impinges  upon  the  gum  or  interferes  with  the  occlusion 
of  the  teeth,  it  is  again  removed  and  trimmed  with  small  curved  scissors 
to  suit  the  requirements  of  the  case,  when  it  is  again  replaced  after  the 
rubber  dam  has  been  adjusted. 

If  the  band  does  not  fit  properly  at  the  cervico-approximal  border,  it 
can  be  brought  to  position  by  the  insertion  of  a  wooden  wedge.  On  the 
removal  of  the  matrix,  which  should  not  be  done  until  the  amalgam  has 
set,  the  filling  can  be  shaped  and  polished  as  though  it  were  gold. 

Mixing  Amalgams. — The  proper  mixing  of  amalgams  is  an  important 
factor  in  the  ''shrinkage-expansion  range"  and  in  the  "flow"  of  the 
mass,  as  shown  by  Dr.  Black.  Amalgams  in  which  the  alloy  has  been  well 
incorporated  with  the  mercury,  or  in  which  the  mercury  has  been  evenly 
distributed,  shrink  or  expand  less — heavily  tinned  amalgams  shrink; 
heavily  silver  amalgams  expand — than  when  they  are  insufficiently  mixed 
or  the  mercury  is  unevenly  distributed.  The  flow  is  likewise  decreased  by 
an  even  distribution  of  the  mercury. 

Alloys  made  of  metals  which  fuse  at  a  comparatively  low  degree  of 
heat,  or  alloys  in  which  these  metals  predominate,  require  less  mercury  to 
dissolve  the  particles  of  the  alloy  and  to  form  a  plastic  mass  than  do  those 
made  of  metals  which  fuse  at  a  considerably  higher  degree  of  heat.  The 
silver-tin  alloys — tin  predominating — require  less  mercury  to  form  a  plastic 
workable  mass  than  the  same  binary  alloy  in  which  the  silver  is  in  excess. 

Flagg  and  Fletcher  both  recommend  the  weighing  of  the  alloy  and  the  7ner- 
cury  for  eyery  "mix."  Flagg's  submarine  alloy,  which  is  composed  of 
silver  60,  tin  35,  copper  5,  requires  from  forty-six  to  forty-eight  per 
cent,  of  mercury  to  make  a  workable  mass. 

Flagg's  contour  alloy,  containing  silver  58,  tin  37,  gold  5,  and  other 
alloys  of  this  grade  require  from  forty-eight  to  fifty  per  cent,  of  mercury 
for  perfect  amalgamation,  while  those  containing  tin  GO,  silver  40,  require 
only  from  thirty-seven  to  thirty-nine  per  cent.,  and  those  composed  of 
tin  60,  silver  35,  gold  5,  from  forty- one  to  forty-three  per  cent,  of 
mercury. 

If  the  operator  knows  the  exact  formula  of  the  alloy  which  he  is  using, 
the  proportion  of  mercury  necessary  to  completely  amalgamate  the  alloy 
is  readily  determined  by  the  above.  If,  however,  he  does  not  possess  the 
formula,  he  can  ascertain  by  an  experimental  "mix"  the  amount  of  mer- 
cury necessary  to  obtain  the  best  results  in  working  any  grade  of  amalgam. 


324 


OPERATIVE    DENTISTRY. 


The  amount  of  mercury  required  for  the  amalgamation  of  dental  alloys 
is  greatly  increased  as  the  amount  of  silver  passes  beyond  sixty  per  cent., 
so  that  with  an  alloy  containing  seventy  per  cent,  of  silver  it  was  very 
difficult  to  form  a  workable  mass  with  fifty  per  cent,  of  mercury  ;  while 
with  eighty  per  cent,  of  silver  it  becomes  necessary  to  use  as  much  as 
sixty  per  cent,  of  mercury. 

In  mixing  amalgams  by  weight,  the  amount  of  the  alloy  necessary  for 
the  case  in  hand  should  first  be  weighed,  and  then  the  exact  proportion  by 
weight  of  mercury  added  to  it.     These  should  be  placed  in  a  mortar  and 

Fig.  450. 


Fig.  451. 


Flagg  wafering  pliers. 

mixed  with  the  pestle  until  the  mercury  is  thoroughly  incorporated, 
making  an  even  mass  of  firm  consistency.  It  is  then  taken  in  the  palm  of 
the  hand  and  kneaded  into  a  mass,  and  compressed  in  a  piece  of  chamois- 
skin  or  silk  fabric,  by  wringing  with 
the  fingers  or  with  a  pair  of  flat-nosed 
pliers,  or  with  Flagg' s  wafering  pliers, 
shown  in  Fig.  450. 

If  the  "mix"  has  been  properly 
proportioned,  no  mercury  can  be  ex- 
pressed by  gentle  pressure  with  the 
pliers,  and  but  very  little  under  severe 
pressure.  The  practice  of  adding 
more  mercury  than  is  needed  in  mix- 
ing an  amalgam,  and  then  expressing 


it  in  order  to  obtain  a  good  working 
mass,  is  to  be  dej)recated,  from  the 
fact  that  the  mercury  is  the  solvent 
or  fusing  element  in  the  amalgam,  and 
whenever  any  portion  of  it  is  taken 
from  the  mass,  by  just  that  much  the 
composition  of  the  amalgam  is  altered  and  its  physical  characteristics 
changed. 

Dr.  Black  advocates  the  plan  of  mixing  the  amalgam  in  the  hand  until 
a  fairly  even  distribution  of  the  mercury  is  secured,  as  by  this  method  his 
experiments  showed  that  the  strongest  amalgam  was  secured.  He  found 
•also  that  '■^  any  form  of  violence  weakens  the  producV^  either  in  mixing,  ex- 
pressing the  excess  of  mercury  by  compression  with  a  vice,  or  by  undue 
manipulation  in  packing  it  into  the  cavity. 

Mixing  amalgams  in  the  hand  is  a  dirty  process,  which  discolors  the 
hand  and  the  fingers  with  the  metallic  oxides.    To  overcome  this  difficulty 


Glass  mortar  and  pestle. 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      325 

Dr.  Genese  invented  a  rubber  mortar  to  be  held  in  the  hand,  the  finger 
used  in  the  mixing  to  be  covered  with  a  rubber  finger-stall. 

Fletcher's  method  of  mixing  is  to  place  the  weighed  proportions  of 
alloy  and  mercury  in  a  long  glass  tube  and  then  violently  shake  it  until 
amalgamation  takes  place. 

The  writer  prefers  to  mix  amalgams  by  placing  the  desired  amount  of 
alloy  in  a  mortar  (Fig.  451)  and  adding  the  mercury  little  by  little  while 
the  mass  is  being  triturated,  until  a  rather  dry,  crumbly  mass  is  formed  ;  it 
is  then  turned  into  the  palm  of  the  hand  and  kneeded  with  the  index-finger 
for  a  little  time,  when  from  the  heat  imparted  to  it  from  the  hand  it  be- 
comes softer,  and  can  be  worked  into  a  mass  that  will  hold  together.  It  is 
then  placed  in  a  napkin  and  compressed  into  a  compact  mass  by  wringing 
and  squeezing  between  the  thumb  and  finger,  and  afterwards  cut  into  cubes 
of  suitable  size  for  the  case  in  hand.  This  forms  a  mass  which  works 
easily  and  without  the  appearance  of  an  excess  of  mercury  upon  the  sur- 
face of  the  filling  during  the  operation  of  packing  it  into  the  cavity. 

Washing  Amalgams. — The  idea  of  washing  amalgams  originated  in 
the  fact  that  alloys  that  had  been  cut  for  some  time  became  oxidized  upon 
the  surface,  and  it  was  thought  caused  discoloration  of  the  filling.  It 
was  believed  that  these  oxides  could  be  removed  by  washing  in  alcohol  or 
other  fluids  and  thus  prevent  discoloration. 

The  real  value  of  washing  amalgams  is,  however,  still  a  mooted  ques- 
tion in  the  profession.  Flagg  believed  that  "washing"  increased  the 
tendency  of  the  filling  to  shrink.  Fletcher  demonstrated  that  "washing" 
was  absolutely  detrimental,  as  it  greatly  facilitated  and  increased  shrink- 
age. Burchard  *  recommends  washing  the  amalgam  in  spirits  of  chloro- 
form, as  it  has  been  observed  that  washed  amalgams  retain  their  color 
better.  The  writer  has  never  been  able  to  discover  any  difference  in  the 
maintenance  of  color  between  washed  and  unwashed  amalgams,  and  he  has 
experimented  very  considerably  in  this  line  and  has  carefully  observed  the 
results  in  the  mouth. 

The  composition  of  the  amalgam  and  the  finish  given  to  the  filling  are 
the  main  factors  in  controlling  the  tendency  to  discoloration. 

INTRODUCTION   OF   THE   AMALGAM. 

The  cavity  having  been  prepared,  the  rubber  dam  adjusted,  and  the 
surface  of  the  dentin  dried  and  sterilized,  the  tooth  is  ready  to  receive  the 
filling.  The  amalgam  should  be  introduced  into  the  cavity  in  small  pieces. 
The  first  piece  should  be  large  enough  to  cover  the  bottom  of  the  cavity 
when  it  is  packed  into  place.  The  packing  should  always  be  done  by 
hand-pressure.  Another  piece  is  then  added  to  this  and  pressed  into 
position  with  suitable  instruments,  and  the  filling  built  up  layer  after  layer 
until  the  cavity  is  full. 

Various  instruments  have  been  devised  for  carrying  the  amalgam  to 
the  cavity  besides  the  ordinary  curved  pliers.  Fig.  452  represents  an 
instrument  for  this  purpose,  which  has  one  end  armed  with  coarse  serra- 

*  American  Text-Book  of  Operative  Dentistry. 


326 


OPERATIVE    DENTISTRY. 


tipns  iuto  which  amalgam  has  been  packed  and  permitted  to  harden.  This 
produces  a  surface  which  will,  by  affinity  or  attraction,  pick  up  small 
pieces  of  amalgam  and  hold  them  until  they  are  deposited  in  the  cavity. 

Other  efficient  instruments  are  shown  in  Fig.  453.     These  are  of  equal 
value  in  carrying  the  amalgam  to  cavities  in  the  teeth  of  the  upper  and 

lower  jaws. 

Fig.  452. 


Loadstone  amalgam -carrier. 

For  packing  the  amalgam  into  the  cavity  and  shaping  the  filling  there 
are  no  better  instruments  than  those  shown  in  Figs.  454,  455,  and  456. 

Fig.  453. 


Amalgam-carriers. 


Packing  and  Condensing.  — Several  methods  have  been  recommended 
for  packing  and  condensing  the  amalgam,— viz.,   by  burnishing,  pressing, 

and  tamping. 

Fig.  454. 


Dr.  J.  Foster  Plagg's  amalgam-instrumeuts. 


Burnishing  the  amalgam  into  place  is  the  method  most  commonly  fol- 
lowed, and  it  is  claimed  for  this  method  that  a  better  adaptation  of  the 
material  to  the  cavity  walls  is  obtained  than  by  any  other.  Dr.  Black  has 
shown  that  "severe  burnishing  makes  a  weak  filling." 

Pressure,  steady  and  light,  has,  according  to  the  same  investigator, 
given  the  best  results  in  his  experiments  upon  the  manipulation  of  amal- 
gams.   Strong  pressure,  while  bringing  free  mercury  to  the  surface,— which 


MANIPUl^ATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      327 


was  removed, — gave  the  next  best  findings.     Burnishing  the  filling  into 
the  cavity,  if  done  moderatelj^,  gave  about  the  same  results. 

Tamping  or  tapping  the  amalgam  into  position  is  a  method  which  was 
introduced  by  Dr.  Flagg,  and  is  described  as  follows :  "Tamping  consists 
of  delivering  light  blows,  from  the  appropriate  filling- instruments,  upon 
the  amalgam  aftey^  it  has  been  crushed  into  approximate  position  and  apposi- 
tion. This  'tamping'  is  not  to  be  done  with  the  mallet,  either  hand, 
automatic,  or  electric,  as  a  different  kind  of  blow  from  any  so  given  is  far 


Fig.  455. 


Fig.  456. 


Kirk's  universal  Revised  set  of  amalgam-instruments. 

approximal  instru- 
ments for  plastics. 

preferable.  Tamping  is  a  mingled  push  and  Mow,  which  is  soon  acquired, 
and  is  as  promptly  recognized  as  very  efficient  in  producing  admirable 
results."  The  writer  has  followed  this  method  for  many  years,  and  has 
never  seen  any  good  reason  for  changing  to  another. 

Wafering.— As  the  filling  nears  completion  many  operators  are  in  the 
habit  of  finishing  it  with  "wafers"  of  hard  amalgam,  after  the  manner 
suggested  by  Flagg.  These  wafers  are  made  by  compressing  a  portion  of 
amalgam — either  from  the  mix  then  being  used  or  of  a  higher  grade  alloy 
— in  chamois,  with  a  pair  of  strong  pliers,  until  all  the  mercury  possible 
is  ex]3ressed  from  it.  The  process  of  wafering  hastens  the  setting  of  the 
amalgam  and  facilitates  the  final  finishing. 

Lining. — In  large  cavities  having  thin  walls  it  often  becomes  necessary 
to  "line"  the  cavity,  in  order  to  give  them  the  needed  support  and  to 
prevent  discoloration  from  the  bluish  appearance  of  the  amalgam  showing 
through  the  enamel,  or  from  discoloration  caused  by  the  formation  of  sul- 
phides and  oxides  of  the  metals  contained  in  the  amalgam. 

The  materials  generally  used  for  this  purpose  are  the  zinc  oxy chloride 
and  oxy  phosphate  cements. 

In  lining  cavities,  the  cement  should  never  be  allowed  to  rest  in  contact 
with  the  enamel  margins.  The  margins  should  always  be  free  from  the 
cement,  so  that  the  amalgam  may  be  in  perfect  contact  with  them  through- 
out their  whole  extent.  If  for  any  reason  the  cement  is  allowed  to  remain 
in  contact  with  the  enamel  margins,  and  the  amalgam  makes  contact  with 
that  instead  of  the  enamel,  failure  of  the  filling  is  bound  to  result  by  the 
washing  away  of  the  cement  and  opening  the  cavity  to  the  agencies  of  caries. 


328  operativp:  dentistry. 

Two  methods  of  lining  are  employed  :  one  is  to  partially  fill  the  cavity 
with  the  cement  and  allow  it  to  become  thoroughly  hardened,  and  then  to 
prepare  it  for  the  amalgam  filling  by  removing  the  cement  from  the  enamel 
margins,  and  give  a  retentive  shape  by  undercuts  in  the  base  of  the  cement. 
Another  method  is  to  line  the  cavity  with  rather  soft  cement,  care  being 
taken  to  keep  the  enamel  margins  free,  and  while  the  cement  is  yet  soft 
to  introduce  the  amalgam,  rubbing  it  into  the  surface  of  the  cement.  It 
is  claimed  for  this  method  that  by  introducing  the  amalgam  while  the 
cement  is  in  a  plastic  state  it  adheres  to  the  enamel  and  renders  retentive 
shaping  unnecessary. 

Guarding. — In  large  cavities  in  the  approximal  surfaces  of  the  bicus- 
pids and  molars  which  extend  beneath  the  gums,  it  becomes  necessary  to 
introduce  a  filling-material  which  by  reason  of  its  physical  character  and 
antiseptic  action  wall  conserve  the  tooth-structure.  Flagg  describes 
"guarding"  as  "placing  a  material  in  apposition  with  the  cervical  wall 
of  a  cavity  of  decay,  which  shall,  by  its  possession  of  certain  physical 
characteristics,  act  under  certain  'law,'  to  prevent,  in  greatest  degree,  the 
recurrence  of  decay  at  that  'vulnerable  spot.'  " 

Tin-foil  is  generally  used  for  this  purpose  under  gold  fillings,  while 
some  operators  use  amalgam. 

In  guarding  the  cervical  margin  under  amalgam  fillings,  alloys  are  used 
which  contain  copper  and  a  high  per  cent,  of  silver.  For  this  purpose 
there  is  no  alloy  better  than  Flagg' s  "submarine,"  composed  of  silver, 
60  ;  tin,  35  ;  cox)per,  5. 

Copper  amalgam  may  also  be  used  for  the  same  purpose,  and  some 
operators  prefer  it. 

Guarding  with  amalgams  is  usually  employed  in  those  cases  in  which 
caries  has  extended  so  far  beneath  the  gum  as  to  make  it  impossible  to 
keep  the  cavity  dry  by  adjusting  the  rubber  dam.  Under  such  circum- 
stances, after  the  cavity  has  been  prepared  an  antiseptic  should  be  applied, 
and  sealed  into  the  cavity  with  a  temporary  stopping.  On  the  next  day, 
after  adjusting  a  napkin  to  prevent  the  entrance  of  moisture,  the  dressing  is 
removed,  and  the  submarine  amalgam,  which  had  been  previously  prepared, 
should  be  rapidly  introduced,  packed  into  position  with  suitable  instru- 
ments or  pellets  of  bibulous  paper,  and  built  up  to  the  gingival  border,  the 
balance  of  the  cavity  being  filled  with  a  temporary  stopping.  The  surface 
of  the  amalgam  should  be  smoothed  and  overhanging  edges  removed  while 
it  is  in  the  plastic  state,  for  after  it  has  "set"  it  is  cut  with  great  difficulty. 
At  a  subsequent  sitting  the  surface  of  the  amalgam  filling  beneath  the 
gum  should  be  nicely  finished,  when  the  rubber  dam  may  be  adjusted,  the 
temporary  stopping  removed,  and  the  balance  of  the  cavity  filled  with 
ordinary  amalgam.  The  amalgam  which  is  used  for  the  bulk  of  the  filling 
should  be  one  which  will  maintain  a  good  color.  An  alloy  containing 
silver  60.  tin  35,  gold  5,  will  best  subserve  the  purpose. 

It  sometimes  becomes  necessary  to  complete  the  operation  at  one  sitting. 
Under  these  circumstances,  the  rubber  dam  can  be  adjusted  after  the  cer- 
vical section  of  the  cavity  has  been  filled  and  the  operation  completed. 
This  method  is,  however,  not  so  satisfactory  as  the  other,  because  of  the 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      329 

danger  of  dis]3lacing  the  cervical  section  of  the  filling  while  the  other  is 
being  packed  into  position,  and  the  greater  difficulty  of  perfectly  finish- 
ing the  cervical  portion  after  the  entire  filling  has  been  completed. 

Flagg  recommends  in  all  of  those  fillings  which  are  located  in  surfaces 
of  the  teeth  exposed  to  view,  and  where  any  discoloration  would  be  objec- 
tionable, wafering  such  fillings  with  "facing"  alloy,  composed  of,  rela- 
tively, silver  57,  tin  35,  gold  5,  zinc  3,  as  this  gives  a  more  accejitable  color. 

COPPER    AMALGAM. 

For  the  purj^ose  of  guarding  and  for  submarine  work  in  unexposed 
jDOsitions,  and  in  the  molar  teeth  of  little  children,  some  of  whom  will 
not  tolerate  the  rubber  dam  or  even  a  napkin,  coi^per  amalgam  occupies  a 
higli  position  as  a  filling-material  and  a  couserver  of  tooth -structure. 

Cavities  prepared  for  this  material  require  but  slight  retentive  shaping 
to  retain  it  in  position. 

Fig.  457. 


Ebony  cone-socket  handle, 

In  preparing  copper  amalgam  for  introduction  into  a  cavity,  a  cube  of 
the  material  is  placed  in  an  iron  spoon  (Fig.  457),  or  grasped  with  a  pair 
of  pliers,  and  held  above  an  alcohol  or  Bunsen  flame  until  the  mercury 
shows  itself  in  tiny  globules  upon  the  surface,  when  it  is  placed  in  a  mor- 
tar, crushed  and  ground  into  a  soft  mass. 

The  cavity,  when  possible,  should  be  protected  from  moisture  by  adjust- 
ing a  rubber  dam  or  a  napkin  and  sterilized.  The  amalgam  is  then  intro- 
duced in  small  pieces,  and  packed  by  tamping  or  burnishing  the  material 
against  the  walls  of  the  cavity  until  it  is  full.  The  surface  of  the  filling 
may  be  smoothed  with  a  broad  spatula  or  by  wiping  with  pellets  of  cotton. 

Large  cavities  may  be  advantageously  filled  or  lined  with  zinc  oxy- 
phosphate  cement  for  the  lower  two-thirds  or  three-fourths  of  the  cavity 
and  the  filling  finished  with  amalgam.  This  practice,  however,  is  im- 
peratively demanded  in  large  and  deep-seated  cavities  which  have  ex- 
tended nearly  to  the  pulp,  to  guard  against  shock  from  thermal  changes. 

By  the  aid  of  "Mack's"  screws,  set  in  the  jjulp-canals,  the  Herbst 
matrix,  and  a  strong,  quick-setting  alloy — Flagg' s  contour — large  contour 
operations,  like  the  building  of  a  large  section  of,  or  the  whole  crown  of,  a 
molar,  may  be  successfully  accomplished,  as  shown  in  Figs.  458,  459,  460, 
and  461.  It  is  important  that  the  matrix  fit  the  cervix  of  the  tooth  closely, 
and  be  so  adjusted  to  the  occlusion  of  the  opposing  teeth  that  the  jaws  can 
be  closed  in  a  normal  manner.     After  the  cavity  has  been  filled  or  the 


330 


OPERATIVE    DENTISTRY. 


crown  restored,  tlie  matrix  sliould  be  allowed  to  remain  for  a  few  hours, 
or  better,  overnigiit,  wlien  the  surfaces  may  be  trimmed  and  shaped  by 
filing  and  grinding. 

In  packing  the  amalgam  great  care,  for  obvious  reasons,  should  be 
exercised  to  secure  perfect  adaptation  of  the  material  to  the  walls  of  the 
matrix  and  the  surfaces  of  the  screws. 


Fig.  458. 


Fig.  459. 


Fig.  460. 


Fig.  461. 


Cavity  prepared. 


Cavity  filled. 


Cavity  prepared. 


Crown  restored. 


If  the  matrix  has  been  carefully  fitted  to  the  cervix  and  the  occlusion 
properly  adjusted,  there  will  be  very  little  trimming  and  carving  required 
to  give  proper  form  to  the  restored  crown. 

Finishing. — The  proper  finishing  of  an  amalgam  filling  is  as  important 
as  the  finishing  of  gold  fillings.  An  imperfectly  finished  filling  will,  by 
the  roughness  of  its  surface,  its  ragged  or  overhanging  edges,  invite  a  re- 
currence of  dental  caries  at  the  enamel  margins  by  the  retention  of  ferment- 
able material  and  the  protection  offered  to  the  zymogenic  bacteria,  while 
fillings  that  are  highly  finished  retain  a  better  color,  or,  in  other  words,  do 
not  tarnish  or  oxidize  so  readily. 

The  process  of  finishing  amalgam  fillings  which  have  become  hard  by 
crystallization  is  so  similar  to  the  finishing  of  gold  fillings  that  it  is  not 
necessary  to  describe  it,  as  it  would  be  only  a  reiteration  of  these  methods. 


GUTTA-PERCHA. 

Gutta-percha  was  first  introduced  to  the  consideration  of  dental  practi- 
tioners a  little  over  fifty  years  ago  (1847)  as  an  admirable  material  for 
temporary  fillings  in  frail  teeth,  on  account  of  the  ease  with  which  it  could 
be  manipulated,  its  non-irritating  and  non-conducting  qualities,  its  in- 
solubility in  the  fluids  of  the  mouth,  and  its  fair  resistance  to  the  attrition 
of  mastication.  Its  color,  dark  brown,  was  so  objectionable  that  it  found 
little  favor  with  the  profession  on  this  account.  But  upon  the  introduc- 
tion soon  afterwards  of  a  secret  preparation  known  as  "Hill's  stopping," 
which  was  white  in  color  and  possessed  all  of  the  advantages  of  the  crude 
gum,  it  rapidly  came  into  use  for  a  temporary  stopping. 

Its  inventor,  Dr.  Hill,  however,  had  very  exalted  views  of  its  value, 
for  he  said,  "Though  I  do  not  expect  it  to  supersede  gold  entirely,  yet  I 
believe  it  can  be  advantageously  substituted  for  that  material  in  many 
instances."  Although  this  opinion  has  never  been  generally  concurred 
in  by  the  profession,  it  was  nevertheless  the  very  best  material  for  tempo- 
rary fillings  that  the  dentist  has  ever  had  placed  in  his  hands  j  and^  in  fact, 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.     331 

it  has  proved  iu  many  instances,  when  introduced  into  cavities  wliich.  by 
their  position  were  not  subject  to  the  attrition  of  mastication,  to  be  worthy 
to  be  classed  as  a  permanent  filling- material,  for  it  has  been  known  in  such 
locations  to  have  perfectly  j)reserved  the  teeth  so  filled  for  from  five  to  ten 
years,  and  even  longer.  With  the  death  of  Dr.  Hill  the  manufacture  of 
the  "stopping"  ceased,  and  although  several  alleged  analyses  of  the 
material  have  been  published,  no  one  has  ever  been  able  to  produce  a 
substance  that  possessed  all  of  the  qualities  of  Hill's  stopping. 

A  formula  which  makes  a  very  good  substitute  for  it,  and  which,  when 
published,  was  claimed  to  be  identical  with  Hill's  formula,  is  as  follows  : 

R   Quicklime,  2  parts  ; 
Quartz,  1  part ; 
Feldspar,  1  part. 

These  are  ground  to  an  impalpable  powder  and  mixed.  Pure  gutta- 
percha is  then  heated  to  a  plastic  state  and  the  powder  kneaded  into  it  as 
long  as  it  will  receive  it  without  becoming  brittle. 

The  white  gutta-percha  preparations  of  to-day  are  made  in  imitation  of 
Hill's  stoj^ping,  but  they  are  only  imitations  to  those  of  the  older  members  of 
the  ]3rofession  who  had  any  experience  in  the  use  of  the  original  material. 

The  gutta-percha  jpreparations  as  manufactured  at  the  present  time  are 
composed  chiefly  of  gutta-percha  and  oxide  of  zinc,  these  materials  being 
kneaded  together — upon  an  iron  or  porcelain  slab  heated  over  boiling 
water — by  the  aid  of  a  broad  steel  wedge-shaped  instrument  termed  a 
kneader.  The  greatest  care  has  to  be  exercised  in  its  manufacture  to 
prevent  overheating  (heat-rotting),  as  this  spoils  the  material  by  destroy- 
ing its  toughness  and  causing  disintegration  of  the  mass. 

Gutta-percha  as  prepared  for  the  use  of  the  dentist  is  in  three  forms, 
— one,  the  well-known  pink  base-plate  gutta-percha ;  another,  the  white 
gutta-percha  prepared  in  small  cakes,  sticks,  or  pellets ;  and  the  third,  a 
softer  "temporary  stopping"  used  for  covering  dressings.  The  white 
gutta-XDercha  is  prepared  in  three  grades, — viz.,  "low  heat,"  "medium," 
and  "high  heat."  The  "low  heat"  grade  becomes  sufficiently  plastic  for 
manipulation  at  temperatures  ranging  from  140°  to  200°  F.  The  "medium" 
grade  is  rendered  of  equal  plasticity  by  a  temperature  ranging  from  200° 
to  210°  F.  The  "high  heat"  grade  requires  a  temperature  of  from  216° 
to  230°  F.  to  render  it  sufficiently  ijlastic  for  manipulation,  and  is  therefore 
more  liable  to  be  overheated  and  its  integrity  destroyed  than  are  those 
which  can  be  rendered  plastic  over  hot  or  boiling  water.  Flagg  thinks  for 
this  reason  the  medium  grade  of  gutta-percha  is  the  best  for  general  use. 

Flagg' s  formulae  for  the  "low  heat"  and  "medium"  grades  of  gutta- 
percha are,  "low  heat,"  gutta-percha,  one  part ;  oxide  of  zinc,  four  parts ; 
"medium,"  gutta-percha,  one  part;  oxide  of  zinc,  six  to  seven  parts  by 
weight. 

Physical  Characteristics.— Gutta-percha  stopping  is  the  most  bland 
and  non-irritating  filling-material  known,  and  by  its  non-conducting  prop- 
erties of  both  heat  and  electricity  it  becomes  the  most  valuable  filling- 
material  for  the  temporary  treatment  of  hypersensitive  dentin  and-  nearly 


332  OPERATIVE    DENTISTRY. 

exposed  pulps  that  the  dentist  has  at  his  command.  It  is  not  acted  upon 
by  tlie  fhiids  of  the  mouth,  at  least  in  any  appreciable  degree,  while  it  is  a 
notable  fact  that  it  maintains  its  integrity  better  in  the  fluids  of  the  mouth 
than  when  exposed  to  the  atmosphere.  Softened  gutta-percha  pellets  will 
unite  with  each  other  under  pressure  when  the  surfaces  are  dry,  but  they 
cannot  be  made  to  do  so  when  wet.  It  contracts  on  cooling,  so  that  it  is 
almost  impossible  to  make  an  absolutely  moisture-tight  plug  ;  in  fact,  very 
few  fillings  made  out  of  the  mouth  will  resist  the  "carmine  test ;"  and  yet 
with  this  great  fault  its  record  as  a  "tooth-saver"  is  exceptionally  good. 
It  is  susceptible  of  being  colored  to  imitate  any  shade  of  the  teeth.  It  is 
not  so  hard  nor  so  rigid  as  the  other  filling-materials,  but  it  has  been  no- 
ticed that  its  hardness  increases  with  time  when  it  has  been  properly  intro- 
duced into  a  cavity  that  is  protected  from  attrition.  Gutta-percha  fillings 
which  soften  and  disintegrate  in  the  mouth  have  been  spoiled  by  "heat- 
rotting,"  either  during  the  process  of  manufacture  or  in  being  prepared 
for  introduction  into  the  cavity.  The  pink  base-plate  gutta-percha  assumes 
a  polished  surface,  and  seems  to  wear  better  when  subjected  to  attrition 
than  do  the  white  varieties. 

Some  operators  prefer  the  pure  gum  to  any  other  form,  believing  that 
its  admixture  with  the  substances  that  are  used  to  harden  and  bleach  it 
detract  from  its  wearing  qualities  and  only  render  it  more  destructible. 

Use  of  Gutta-Percha. — Gutta-percha  is  employed  principally  as  a 
temporary  filling  in  the  deciduous  and  permanent  teeth,  for  "sealing  in" 
dressings,  treating  hypersensitive  dentin,  for  the  permanent  filling  of 
root-canals,  for  "guarding"  oxyphosphate  fillings,  for  capping  or  pro- 
tecting nearly  exposed  pulps,  for  permanent  fillings  in  locations  not  ex- 
posed to  attrition,  and  in  badly  broken-down  teeth  which  are  too  frail  to 
be  filled  with  metallic  stoppings.  Dissolved  in  chloroform — chloro-percha 
— it  is  often  used  to  line  cavities  which  are  to  receive  zinc  oxychloride  or 
zinc  oxyphosphate  cements,  the  object  being  to  jirotect  the  pulp  from  irri- 
tation and  pain  which  might  be  induced  from  the  zinc  chloride  in  the 
former  and  the  glacial  phosphoric  acid  in  the  latter. 

The  form  of  gutta-percha  known  as  "temj)orary  stopping"  is  furnished 
in  two  colors,  pink  and  white,  and  is  used  j^rincipally  for  "sealing  in" 
dressings  that  have  been  placed  in  carious  cavities  to  reduce  hypersensi- 
tiveness  or  to  destroy  the  vitality  of  the  pulp^  or  for  covering  dressings 
that  have  been  placed  in  the  root-canals  of  devitalized  teeth.  On  account 
of  its  extreme  softness,  however,  it  is  not  intended  to  subserve  more  than 
the  most  temporary  purpose,  although  this  feature  makes  it  very  valu- 
able, as  it  is  easily  and  quickly  introduced,  and  as  easily  and  quickly 
removed. 

Many  operators  confine  their  use  of  the  pinTc  variety  to  covering  arseni- 
cal applications  and  other  dressings  which  the  conditions  of  the  tooth 
make  imperative  should  be  changed  at  the  next  sitting,  while  the  white 
is  used  for  those  cases  which  are  not  urgent,  or  are  being  tested  as  to  their 
fitness  to  receive  a  permanent  filling. 

Gutta-percha  which  is  prepared  for  filling  the  root-canals  of  devitalized 
teeth  is  made  in  the  form  of  long  slender  cones  or  points,  either  by  rolling 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      333 

or  cutting  of  proper  size  and  form  to  be  readily  introduced  into  the 
canals.  They  may  be  prepared  either  from  the  pink  base-plate  gutta- 
percha or  from  the  white  variety. 

Gutta-percha  by  reason  of  its  indestructibility,  non- irritating  character, 
ready  adaptability,  and  ease  of  manipulation  is  the  material  pay^  excellence 
for  filling  root-canals. 

For  "  guarding^  ^  zinc  oxyphosphate  fillings  at  the  cervical  margin  it  is  of 
great  value,  for  it  prevents  the  dissolution  of  the  cement  which  is  so  com- 
mon at  this  location,  and  thereby  relieves  the  anxiety  of  the  oj^erator  over 
the  possibility  of  the  oxyphosphate  being  undermined  in  a  few  months 
and  the  carious  process  re-established.  In  many  individuals  the  oxyphos- 
IDhate  cement  wears  well,  even  in  positions  exposed  to  the  attrition  of  mas- 
tication, but  is  rapidly  disintegrated  at  the  cervical  margins.  By  "guard- 
ing" with  gutta-percha  at  these  locations  the  durability  and  value  of  such 
fillings  is  greatly  increased. 

As  a  capping  for  nearly  exposed  pulps  gutta-percha  of  the  "low  heat" 
grade  has  no  equal,  its  greatest  value  lying  in  its  non-conducting  quality, 
which  protects  the  pulp  from  thermal  shock. 

As  a  permanent  filling  in  large  cavities  in  the  deciduous  and  permanent 
teeth  not  subjected  to  the  friction  of  mastication,  especially  buccal  cavi- 
ties in  molars  and  simple  labial  or  approximal  cavities,  the  "high  heat" 
grade  may  be  depended  upon  to  wear  well  and  to  protect  from  a  recurrence 
of  caries.  It  has  its  greatest  usefulness  in  those  cavities  in  which  the 
carious  process  has  penetrated  to  such  depth  as  to  nearly  expose  the  pulp, — 
the  pulp  being  first  protected  by  a  layer  of  the  "low  heat"  grade,— and  in 
devitalized  teeth  which  have  very  frail  cavity  walls  or  are  inclined  to 
pericemental  or  apical  irritation,  and  by  reason  of  its  non-irritating 
quality  in  all  cavities  which  extend  beneath  the  free  margin  of  the  gum. 
Many  operators  use  it  to  the  exclusion  of  all  other  filling- materials  for 
stopping  approximal  cavities  in  the  anterior  permanent  teeth  of  children 
under  twelve  to  fourteen  years  of  age.  Fillings  in  these  locations,  if 
properly  introduced,  may  be  counted  upon  for  doing  good  service  for  from 
five  to  eight  years  or  longer. 

The  pink  base-plate  gutta-percha  wears  better  in  all  exposed  surfaces 
than  the  white,  but  the  white,  by  reason  of  its  more  harmonious  color, 
should  be  invariably  used  in  all  cavities  in  the  anterior  part  of  the  mouth. 

The  i^ink  base-jDlate  is  also  a  very  serviceable  material  for  maintaining  a 
temporary  separation  of  teeth  which  are  to  be  filled  with  metallic  stoi)pings, 
but  in  which  the  pericemental  irritation  induced  by  the  sepai^ating  pro- 
cess is  so  great  as  to  make  it  necessary  to  j)ostpone  the  ox^eration  to  a  later 
date.  Or  it  may  be  used  for  gaining  temporary  separations  between  the 
bicuspids  and  molars  prei^aratory  to  introducing  contour  fillings,  by  pack- 
ing the  approximal  cavities  full  of  the  material  and  allowing  the  force  of 
mastication  coming  upon  the  fillings  to  gradually  separate  the  teeth  by  the 
spreading  of  the  material. 

Methods  of  Softening. —  Upon  the  proper  softening  of  the  prepared  gutta- 
percha stoppings  depends  their  integrity  and  durability.  The  greatest  of  care 
should  be  exercised  in  softening  gutta-percha  that  it  be  not  overheated  5  this 


334 


OPERATIVE   DENTISTRY. 


Fig.  462. 


caution  cannot  be  emphasized  too  strongly,  as  tlie  complaints  so  often  made 
of  gutta-perclia  '^rotting"  or  disintegrating  in  the  mouth  are  the  result  of 
overheating,  or  ^' heat-rotting,"  before  introducing  the  filling,  and  not  dis- 
integration of  the  material  from  the  action  of  the  oral  secretions,  as  some 
have  supxjosed. 

Permanent  results  cannot  be  obtained  with  gutta-percha — except  by 
accident — when  the  material  is  heated  by  holding  it  in  the  flame  of  a  lamp 
or  Bunsen  burner,  as  practised  by  so  many  operators,  as  by  this  method  it 
is  usually  overheated,  and  as  a  result,  when  subjected  to  the  influences  of 
the  oral  secretions,  softening  and  disintegration  take  place. 

Dr.  Flagg  some  years  ago  invented  the  device  shown  in  Fig.  462  for 
heating  the  various  grades  of  gutta-percha  and  the  packing  instruments. 

It  is  composed  of  a  lamp-stand, 
which  carries  a  small  metal  wa- 
ter-tank, upon  the  cover  of  whicli 
are  arranged  two  shelves ;  tlie 
upper  one,  which  receives  the 
least  amount  of  heat,  is  intended 
for  softening  the  "low  heat" 
grade  of  gutta-percha,  the  lower 
one  softening  the  "medium" 
grade,  while  the  cover  of  the 
tank  is  utilized  for  heating  the 
"high  heat"  grade  and  the  pack- 
ing instruments,  the  handles  of 
which  rest  upon  a  notched  rack 
and  the  ijoints  upon  the  cover  of 
the  tank.  Water  is  placed  in 
the  tank  and  heated  to  the  boil- 
ing-point. Overheating  of  the 
various  grades  of  the  material  becomes  impossible  by  using  this  method 
of  softening. 

Of  late  years  there  has  been  a  demand  upon  the  part  of  some  0]3erators 
for  harder  grades  of  gutta-percha,  which  require  a  degree  of  heat  for  their 
softening  greater  than  can  be  obtained  by  boiling  water.  The  thermoscopic 
heater  of  Dr.  W.  Storer  How,*  shown  in  Fig.  463,  meets  these  require- 
ments in  a  most  perfect  and  scientific  manner.  The  heater  is  composed  of 
a  block  of  steatite,  selected  for  its  heat-retaining  qualities  and  the  desira- 
bility of  its  surface.  At  one  end  is  a  wooden  handle,  at  the  other  end  a 
circular  recess,  in  the  centre  of  which  is  a  small  disk.  A,  made  of  fusible 
metal  which  melts  at  212°  F.  On  the  heater  within  the  circular  recess  are 
placed  a  suitable  number  of  gutta-percha  i)ellets,  as  1,  1,  and  the  heater 
is  held  over  the  flame  of  a  spirit-lamjp  or  Bunsen  burner  until  the  disk 
of  fusible  metal  is  melted,  when  the  gutta-percha  will  be  sulflciently 
softened  for  introduction  into  the  cavity.  The  heater  will  maintain 
the  proper  temperature  long  enough  for  the  completion  of  an  ordinary 


Flagg's  improved  gutta-percha  softener  and 
tool-heater. 


*  Dental  Cosmos,  vol.  xxxiv.  p.  281. 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      335 

operation,  but  if  tlie  metal  in  the  mean  time  loses  its  fluidity  and  tlius 
indicates  tlie  lowering  of  the  temperature,  it  can  be  restored  hj  hold- 
ing the  heater  for  a  moment  over  the  flame  until  the  metal  again  becomes 
fluid. 

Fig.  463. 


Dr.  How's  thermoscopic  heater. 


When  the  metal  disk  is  fused  the  pellets  1,  1,  will  be  at  a  temperature 
of  about  212°  F.,  while  pellets  at  2  would  have  a  temperature  of  about  200° 
F.,  and  those  at  3  and  4  about  194°  and  180°  F.  respectively.  Disk  B, 
which  is  made  of  fusible  metal  which  melts  at  230°  F.,  is  provided  as  a 
substitute  for  disk  A,  which  may  be  melted  and  poured  out,  and  B  used  in 
its  stead.  In  this  manner  the  "high  heat"  gutta-percha  and  the  lower 
grades  may  be  properly  softened  without  the  least  degree  of  "heat-rotting" 
of  the  material. 

Manipulation  of  Gutta-Percha. — Instruments  which  are  suitable  for 
filling  difficult  and  inaccessible  cavities  with  gold  are  best  adapted  for 
packing  gutta-percha,  for,  as  a  rule,  the  cavities  in  which  this  material 
is  generally  used  are  in  difficult  and  inaccessible  locations.  In  packing 
this  material  it  is  best  to  use  warm  instruments,  as  it  is  important  that  the 
whole  mass  of  the  filling  be  kept  in  a  plastic  state  until  perfect  adaptation 
to  the  walls  has  been  secured. 

The  jpreparation  of  cavities  to  receive  gutta-percha  fillings,  while  re- 
quiring the  thorough  removal  of  all  decalcified  and  infected  dentin,  should 
also  be  directed  to  the  conservation  of  the  enamel  walls  to  the  full  limit 
of  safety  against  fracture,  especially  in  preparing  approximal  cavities  in 
the  incisors  and  cuspids. 

With  an  intact  labial  enamel  wall,  though  it  be  transparent,  gutta- 
percha can  be  so  packed  against  it  as  to  protect  and  strengthen  it,  and 
at  the  same  time  so  restored  in  color  as  to  defy  detection  except  by  close 
scrutiny. 

It  is  important  in  the  introduction  of  gutta-percha  that  moisture  be  ex- 
cluded from  the  cavity.    The  rubber  dam  should  therefore  be  adjusted,  and 


336  OPEEATIVE   DENTISTRY. 

as  much  care  taken  in  this  respect  as  would  be  given  to  it  if  the  cavity 
were  to  'be  filled  with  gold.  The  cavity  should  next  be  dried  and  steril- 
ized, and  again  dried,  after  which  the  gutta-percha  may  be  packed  in 
place.     This  may  be  done  by  either  one  of  two  methods. 

The  first  method  is  by  introducing  the  gutta-percha  in  small  pellets 
into  the  cavity, — which  has  been  previously  warmed  by  a  blast  of  heated 
air, — packing  them  first  into  the  most  inaccessible  parts  of  the  cavity,  and 
finishing  with  a  larger  mass. 

The  second  method  is  to  introduce  a  single  large  mass  somewhat  larger 
than  the  cavity,  and  with  a  broad  spatula-like  instrument,  with  a  rocking 
motion  work  it  into  the  cavity  much  as  would  be  done  in  taking  an  im- 
pression of  the  part. 

Some  operators  prefer  to  line  the  cavity  walls  with  oxychloride  or 
oxyphosphate  of  zinc  cement  in  those  cases  in  which  the  walls  are  very 
thin  and  frail ;  tinting  these  materials  to  match  the  color  of  the  tooth,  and 
after  it  has  hardened  to  fill  the  balance  of  the  cavity  with  gutta-percha 
after  one  of  the  above  methods. 

Dr.  How  believes  that  the  common  method  of  introducing  the  filling  in' 
small  pellets  is  responsible  for  leaky  fillings.  He  says,  ^' There  is  good 
reason  for  the  belief  that  the  common  mode  of  successively  introducing 
small  pieces  of  perfectly  softened  gutta-percha  into  a  comparatively  cold 
cavity,  and  employing  instrument  points  more  or  less  heated  for  packing 
the  cooled  plastic  against  one  side  of  the  cavity  after  another,  must  in  the 
nature  of  the  case  result  in  a  leaky  filling,  such  as  gutta-percha  is  com- 
monly said  to  make,  whereas  the  defect  is  due  not  to  the  material,  but  to 
its  inconsiderate  manipulation."  Dr.  How  claims  that  by  the  "single 
mass"  method  perfectly  moisture-tight  plugs  can  be  made,  as  demonstrated 
by  him,  such  fillings  successfully  resisting  the  aniline-dye  test  after  several 
days'  immersion. 

Finishing  Gutta-Percha  Fillings. — Gutta-percha  fillings  which  have 
been  properly  introduced  need  but  little  trimming  or  finishing.  To  hasten 
the  hardening  of  the  filling,  a  spatula  which  has  been  immersed  in  ice- 
water  and  quickly  dried  should  be  applied  to  the  surface  of  the  filling  to 
abstract  the  heat,  and  as  soon  as  it  has  been  sufficiently  cooled  the  over- 
lapping edges  may  be  removed  with  Dr.  Gordon  White's  sickle-shaped 
trimmers  (Fig.  444)  or  those  of  Dr.  E.  K.  Wedelstaedt.  The  surplus  ma- 
terial should  be  shaved  off  in  thin  slices,  never  in  large  mass,  as  this  effort 
would  be  likely  to  drag  the  filling  away  from  the  margins.  The  trimming 
should  always  be  from  the  centre  of  the  filling  towards  the  circumference, 
for  the  same  reason.  The  surface  may  be  finished  by  a  rapidly  revolving 
cuttle-fish  disk,  or  by  wiping  the  surface  of  the  filling  with  a  tape  mois- 
tened in  chloroform. 

ZINC   CEMENTS. 

The  zinc  cements — or  "osteoplastics"  as  they  are  sometimes  called — 
used  in  dentistry  are  the  oxychloride,  the  oxyphosphate,  and  the  oxy- 
sulphate.  The  oldest  of  these  is  the  oxychloride,  which  was  first  intro- 
duced to  the  profession  about  the  year  1850,  or  a  little  later,  by  M.  Sorrel 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      337 

as  a  permanent  filling-material,  and  on  account  of  its  hardness,  whiteness, 
and  apparent  insolubility,  it  gave  promise  at  first  of  fulfilling  the  expecta- 
tions of  its  inventor,  but  later  all  hopes  in  this  respect  were  abandoned,  as 
it  was  found  to  undergo  rapid  disintegration  whenever  the  material  was 
placed  in  contact  with  the  margin  of  the  gum  or  very  near  to  it,  and  it  also 
contracted  very  considerably  in  hardening,  and  therefore  resulted  in  leaky 
fillings. 

Zinc  oxycliloride  is  formed  by  the  combination  of  calcined  and  pulver- 
ized zinc  oxide  with  a  solution  of  zinc  chloride  in  distilled  water  :  ZnO  + 
ZnCl,  +  H,0  =  2ZnClHO. 

''  Zinc  oxide  is  made  by  heating  metallic  zinc  in  a  current  of  air.  To 
make  a  pure  white  zinc  oxide  for  pharmaceutical  purposes,  pure  precipi- 
tated zinc  carbonate  should  be  heated  at  low  red-heat  until  the  water  and 
carbonic  oxide  are  wholly  exx^elled.  This  can  be  done  below  500°  F.  Too 
high  heat  will  give  the  product  a  yellow  color  and  make  it  feel  harsh.  A 
small  quantity  should  be  used  in  heating.  A  good  quality  of  zinc  oxide 
should  come  in  the  form  of  a  soft,  flaky,  impali^able  powder  of  si3.  gr.  5.6. 
It  should  turn  yellow  when  heated  in  a  test-tube,  and  become  white  again 
on  cooling.  It  is  insoluble  in  water,  but  completely  soluble  in  dilute  acids. 
It  is  not  darkened  by  sulphuretted  hydrogen. 

^^Zinc  chloride  is  made  by  heating  zinc  in  a  current  of  chlorine,  or  by 
the  action  of  hydrochloric  acid  on  granulated  zinc,  or  zinc  carbonate,  and 
evaporating  the  solution  to  dryness.  It  occurs  in  the  form  of  hard,  dirty- 
white  masses,  very  deliquescent,  and  forming  a  clear  solution  in  water.  It 
is  one  of  the  most  soluble  substances  known.  Zinc  chloride  has  a  caustic, 
sharp  taste,  and  is  acid  in  reaction.  It  is  soluble  in  alcohol  and  in  ether." 
(Mitchell.) 

Zinc  oxychloride  as  prepared  for  dental  use  is  composed  of  a  powder 
and  a  liquid. 

The  poicder  is  made  by  thoroughly  triturating  in  a  mortar  two  grains 
of  borax  and  four  x^ennyweights  of  zinc  oxide.  These  are  then  placed  in 
a  small  crucible  and  subjected  to  a  glowing  red-heat  for  from  seven  to  ten 
minutes,  forming  what  is  termed  a  ^^frit,"  which  when  cooled  is  finely 
Xjulverized  in  a  mortar.  Sixteen  pennyweights  of  zinc  oxide  are  then 
placed  in  a  crucible  and  subjected  to  a  moderate  red-heat  for  three  or  four 
minutes,  and  allowed  to  cool.  After  which  it  is  gradually  added  to  the 
'■ '  frit, ' '  and  the  whole  thoroughly  pulverized  and  mixed.  It  should  then 
be  transferred  to  a  glass- stoppered  bottle  to  x^rotect  it  from  the  moisture  of 
the  atmosphere. 

The  liquid  is  made  by  dissolving  half  an  ounce  of  zinc  chloride  in  two 
or  two  and  a  half  drachms  of  water,  and  after  several  shakings  allowed  to 
settle  for  a  few  days,  when  the  clear  fluid  may  be  decanted  off.  If  the 
solution  does  not  clear  it  should  be  filtered.     (Flagg.) 

Mixing. — For  mixing  zinc  oxychloride,  or  in  fact  any  of  the  zinc 
cements,  a  glass  slab  and  a  suitable  spatula  are  necessary  (Fig.  464). 
Upon  the  mixing-slab  are  placed  one  or  two  drox^s  of  the  fluid,  and  near  it 
a  quantity  of  the  powder.  These  are  then  incorporated  and  worked  into  a 
thick  creamy  paste,  and  it  is  ready  for  use.     The  filling  is  introduced  into 

22 


338 


OPERATIVE    DENTISTRY. 


the  cavity  by  small  spatulas  (Fig.  4G5),  and  adapted  to  the  walls  by  means 
of  pellets  of  bibulous  paper,  which  remove  any  surplus  of  liquid,  and  thus 
hasten  the  setting. 

Characteristics  and  Properties. — Zinc  oxychloride  sets  rather  slowly 
and  is  not  so  hard  when  set  as  the  oxyphosphate  cements.  About  fifteen  min- 
utes are  required  for  it  to  set  sufficiently  hard  to  allow  amalgam  to  be 
packed  upon  it  without  displacement,  and  half  an  hour  to  an  hour  for  a 

Fig.  4G4. 


Fig.  465. 


Bevelled  edge  (glass)  mixing-slab  and  spatula. 

gold  filling.  Some  operators  defer  the  operation  of  covering  it  with  a 
metallic  filling  until  a  future  sitting,  protecting  the  cement  with  a  gutta- 
percha filling  until  that  time,  in  order  that  the  cement  may  furnish  a 
harder  foundation  for  the  metallic  filling. 

When  used  in  large  masses  it  shrinks  notably.     It  stands  low  in  the 
scale  as  a  conductor  of  caloric,  and  like  all  compounds  which  contain  zinc 
oxide,  it  is  readily  decomposed  by  the  action  of  acids 
and  alkalies. 

Zinc  oxychloride  is  not  a  definite  chemical  compound, 
and  cannot  be  made  by  the  method  of  mixing  without 
one  or  the  other^of  the  constituents  being  found  in  excess. 
According  to  C.  S.  Tomes,  there  is  always  free  zinc 
chloride  to  be  found  in  the  finished  filling,  and  conse- 
quently the  filling  is  hygroscopic. 

When  freshly  mixed,  if  it  is  brought  into  contact  with 
vital  soft  tissues  it  is  irritating  and  escharotic.  Conse- 
quently it  should  never  in  the  creamy  state  of  the  mix  be 
brought  into  contact  with  an  exposed  pulp,  or  one  nearly 
exposed,  as  inflammation  and  devitalization  in  a  large 
majority  of  instances  would  be  the  result.  If  the  ma- 
terial is  mixed  to  a  doughy  consistency,  it  may  sometimes 
be  used  as  a  capi^ing  for  nearly  exposed  i^ulps.  The  danger  to  the  i3ul]3 
lies  in  the  irritating  effect  of  an  excess  of  the  zinc  chloride.  After  the 
filling  has  set,  it  retains  antiseiDtic  properties  for  some  time  thereafter, 
as  shown  by  Miller  in  his  experiments  upon  the  antiseptic  properties  of 
filling-materials. 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      339 

Zinc  oxychloride  has  also  an  obtunding  effect  upon  hypersensitive 
dentin  if  left  in  the  cavity  for  a  month  or  more.  It  is  also,  by  reason  of 
its  antiseptic  properties,  an  excellent  material  with  which  to  fill  the  roots 
of  devitalized  teeth.  It  may  be  used  alone  for  this  purpose,  or  combined 
with  other  materials  like  gold-foil,  gold  wire,  lead,  or  gutta-percha  points  ; 
while  on  account  of  its  extreme  whiteness  it  may  be  successfully  used  as  a 
lining  of  cavities  to  restore  the  color  of  devitalized  teeth. 

Zinc  Oxyphosphate. — Cements  of  this  class  are  formed  by  a  combina- 
tion of  calcined  zinc  oxide  and  orthophosphoric  acid,  3ZnO  +  2H3PO^= 
Zn3(POj2  +  3H^0,  nominally,  for  on  account  of  the  impurities  in  the  zinc 
oxide  and  of  the  inconstancy  of  the  acid  itself,  their  actual  composition 
is  one  of  considerable  variability.' 

"Phosphoric  acid  has  modifications — metaphosphoric  and  pyrophos- 
phoric  acids — which  differ  from  it  in  the  number  of  the  combined  equiva- 
lents of  water  ;  and  these  forms  pass  into  one  another  somewhat  readily. 
Thus  a  solution  of  metaphosphoric  acid  when  boiled  passes  into  orthophos- 
phoric acid  ;  pyrophosphoric  acid  may  be  prex)ared  by  evaporating  a  solu- 
tion of  orthophosphoric  acid  at  a  temperature  of  about  215°  F.  ;  but  it,  in 
the  presence  of  water,  slowly  passes  back  into  the  orthophosphoric  acid 
at  ordinary  temperatures.  Each  of  these  acids  is  capable  of  forming  a 
number  of  different  salts — monobasic,  dibasic,  tribasic,  or  tetrabasic  salts 
— with  the  same  metal,  and  thus  a  large  number  of  zinc  jphosphates  are 
known."     (C.  S.  Tomes.) 

Zinc  oxypliosphate  as  known  to  the  dentist  is  composed  of  a  powder  and 
a  liquid.  The  powder  is  zinc  oxide,  the  liquid  one  of  the  many  forms  of 
phosphoric  acid. 

When  glacial  phosphoric  acid  is  used,  the  cement  is  termed  oxymeta- 
phosphate.  Cements  which  are  made  from  the  commercial  phosiDhoric  acid 
are  not  so  durable  as  are  those  which  are  made  from  the  pure  acid. 

Purity  in  the  materials  which  enter  into  the  composition  of  the  zinc 
oxyphosphates  is  a  sine  qua  non. 

Some  manufacturers  are  in  the  habit  of  preparing  the  powder  from  the 
commercial  metallic  zinc,  and  as  a  result  it  often  contains  impurities,  like 
the  arsenic  compounds,  which,  according  to  some  writers,  exijlains  in  a 
measure  the  reason  why  teeth  which  have  been  filled  with  oxyphosiahate 
cement,  and  vital  teeth  carrying  crowns  and  suj)porting  bridges  which 
have  been  set  with  this  material,  have  sometimes  been  devitalized. 

The  writer,  however,  has  never  seen  a  case  of  devitalization  of  the 
pulp  under  zinc  oxyphosphate  which  could  not  be  satisfactorily  ex^^lained 
upon  some  other  hypothesis. 

Ames,  in  exi^erimenting  on  the  zinc  oxyphosphates  {Dental  Cosmos, 
1890),  x)repared  specimens  of  zinc  oxide  containing  seven  per  cent,  of 
arsenous  oxide  (zinc  arsenite),  and  with  this  compound  apjDlied  to  cavities 
in  vital  teeth  he  was  unable  to  produce  devitalization  of  the  pulj). 

The  zinc  oxide  and  arsenic  compound  used  in  these  exj)erimeuts  was 
prepared  "by  heating  in  a  sealed  tube  certain  proportions  of  zinc  oxide 
and  arsenous  oxide.  In  confinement  a  full  red  heat  will  effect  a  thorough 
combination  of  the  maximum  amount  of  arsenic  with  the  zinc,   which 


340  OPERATIVE   DEKTISTRY. 

seems  to  be  about  seven  per  cent.  This  is  sufficient  to  give  an  extensive 
mirror  with  the  Marsh  test.  This  combination  is  such  that  3000°  F.  can 
afterwards  be  applied  to  the  compound  in  an  open  crucible  without  affect- 
ing the  composition.  This  is  necessarily  the  same  compound  which  is 
formed  in  infinitesimal  quantities  in  the  manufacture  of  cement  powders." 
He  believes  that  tlie  arsenic  found  in  the  zinc  cements  is  in  combination 
with  the  zinc  in  the  form  of  zinc  arsenite,  and  that  tliis  combination  is 
wholly  devoid  of  poisonous  properties  per  se  ;  and  that  the  combination  is 
not  broken  up  to  the  extent  of  forming  potent  arsenous  acid,  except  under 
rare  and  unjustified  conditions. 

To  obtain  zinc  oxide  and  glacial  phosphoric  acid  in  a  pure  state  are 
expensive  processes ;  the  temptation,  therefore,  of  the  manufacturers  to 
send  out  materials  which  are  less  troublesome  to  make  and  of  inferior 
grade  is  very  great. 

The  jpoivder  is  made  by  treating  zinc  oxide  with  nitric  acid,  evaporating 
it  to  dryness,  calcining  and  pulverizing.  (Flagg.)  The  calcining  process 
requires  several  hours,  the  material  being  kept  at  the  highest  forge  heat 
during  this  time,  thus  forming  a  vitreous  mass,  which  on  cooling  is  re- 
moved by  breaking  away  the  crucible.  After  thorough  pulverization  it  is 
sifted  through  a  fine  bolting-cloth  and  placed  in  tightly  stoppered  bottles  to 
protect  it  from  the  atmosphere,  for  if  it  is  exposed  it  absorbs  carbon  diox- 
ide from  the  air,  and  a  portion  of  the  material  is  converted  into  hydrated 
zinc  carbonate.  The  presence  of  carbon  dioxide  is  noticed  by  the  effer- 
vescence which  takes  place  in  such  samples  when  phosphoric  acid  is  added 
to  them,  the  effervescence  being  due  to  the  liberation  of  carbonic  oxide. 
Coarse  powders,  according  to  Ames,  produce  cements  with  greater  crush- 
ing stress  than  those  made  from  fine  powder. 

Eollins's  process  for  making  the  j)owder  is,  "Dissolve  pure  zinc  in 
chemically  pure  nitric  acid  to  saturation,  then  evaporate  to  dryness,  i^ack 
in  a  crucible,  and  heat  until  no  more  fumes  are  given  off.  When  cool 
break  up  the  crucible,  and  after  separating  the  oxide  of  zinc,  pulverize  it 
to  a  fine  powder." 

Flagg  terms  the  zinc  oxide  made  in  this  manner  "nitrate  of  zinc,"  and 
claims  it  makes  a  far  superior  cement  to  those  j)owders  which  are  x^roduced 
by  calcining  zinc  oxide. 

The  liquid  which  is  combined  with  the  powder  in  making  zinc  oxy phos- 
phate cement  (oxymetaphosphate)  is  glacial  phosphoric  acid,  HPO3 
(metaphosphoric  acid).  This  form  of  the  acid  is  derived  by  subtract- 
ing two  molecules  of  water  from  orthophosphoric  acid,  H^PO^  —  2H2O  = 
HPO3,  metaphosphoric  acid. 

Eollins's  process  of  making  metaphosphoric  acid  is,  "Take  a  pure 
solution  of  orthophosphoric  acid,  which  is  easily  obtainable,  of  a  strength 
of  sixty  per  cent. ;  evaporate  it  in  a  platinum  evaporating  dish  until  white 
fumes  are  given  off.  Then  heat  it  to  a  bright  redness  to  be  sure  that  it  is 
all  converted  ;  cool  and  make  into  a  thick  syrup."     (Mitchell.) 

The  impurities  found  in  the  commercial  glacial  phosphoric  acid  forbid 
its  use  in  the  making  of  zinc  oxyphosphate  cement.  These  impurities  con- 
sist of  variable  quantities  of  sodium,  calcium,  and  magnesium  phosphates. 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      341 

"These  salts  are  permanently  soluble  in  tlie  phosphoric  acid,  and  therefore 
give  no  evidence  of  their  presence  by  the  formation  of  i^recipitates.  They 
are  also  soluble  in  water,  which  fact  has  a  direct  bearing  upon  the  dura- 
bility of  cements  made  with  the  impure  add."     (Burchard.) 

The  various  preparations  of  phosphoric  acid  are  proverbially  unstable, 
and  none  more  so  than  the  metaphosphoric  acid  used  in  the  formation  of 
the  zinc  oxyphosphate  cements. 

PrecixDitates  are  often  thrown  down  in  a  few  weeks  after  manufacture 
or  crystallization  takes  place.  The  j)recipitates  are  in  all  j^robability 
metallic  phosphates,  while  crystallisation  may  be  due  to  imperfect  conver- 
sion during  the  process  of  heating.  These  acids  are  all  strongly  hygro- 
scopic ;  the  metaphosx^horic  acid  being  slowly  converted  into  the  common 
l^hosphoric  acid  by  abstraction  of  water  from  the  atmosx)here.  It  is  there- 
fore  imj)ortant  that  the  liquid  be  kept  tightly  corked  when  not  in  use  to 
prevent  change  taking  x)lace  in  it,  if  the  best  results  are  to  be  obtained 
with  the  cement. 

Properties  and  Uses. — Zinc  oxy^jhosphate  cements  possess  certain 
properties  which  make  them  exceedingly  useful  in  the  daily  practice  of  the 
dentist,  the  most  important  of  which  are  :  First,  as  a  lining  for  large 
cavities  with  thin,  frail  walls  it  is  far  sui)erior  to  zinc  oxychloride,  by 
reason  of  its  stronger  adhesion  to  the  walls  of  the  cavity,  thereby  in- 
creasing their  strength  and  lessening  the  danger  from  fracture,  and  its 
greater  hardness,  which  makes  it  a  better  foundation  for  metal  fillings ; 
second,  as  a  temporary  filling  in  devitalized  teeth  which  have  been  placed 
ux)on  probation,  in  vital  teeth  having  large  and  very  sensitive  cavities, 
and  in  the  deciduous  teeth  of  children,  by  reason  of  its  easy  introduction, 
ready  adaptability,  and  its  evident  obtunding  effect  ujoon  hypersensitive 
dentin  ;  third,  for  sealing  in  arsenical  dressings  ;  and  fourth,  for  cementing 
crowns,  bridges,  orthodontic  appliances,  and  inlaw's. 

As  a  conductor  of  caloric  it  possesses  a  slightly  higher  ratio  than  zinc 
oxychloride.  On  account  of  the  strong  affinity  of  metax)hosphoric  acid 
for  water  it  often  causes  jDain  when  first  j^laced  in  sensitive  cavities  by 
abstracting  the  moisture  from  the  dentinal  tubuli,  while  if  i)laced  in  con- 
tact with  an  exposed  or  nearly  exposed  pulp  the  j)ain  is  often  excruciating. 
This  may  be  obviated  by  lining  the  cavity  with  one  of  the  quick-drying 
ethereal  varnishes  or  by  interi)os;ng  a  laj^er  of  softened  gutta-percha. 

Zinc  oxyphosphate,  however,  should  never  be  used  for  fillings  which 
approach  the  gingival  margin  or  extend  beneath  it  without  guarding  this 
vulnerable  point  with  gutta-percha.  Zinc  oxyphosphate  is  readily  dis- 
solved by  solutions  of  lactic  acid,  and  this  is  almost  always  iDresent  at  the 
crevices  of  the  teeth,  along  the  borders  of  the  gingivae  and  in  the  inter- 
approximal  spaces.  Fillings  thus  guarded,  if  well  made,  will  last  from 
one  to  five  years,  and  in  favorable  cases  they  have  been  known  to  do  good 
service  for  a  much  longer  j)eriod,  while  the  operator  will  be  relieved  of 
the  anxiety  incident  to  the  tendency  of  the  material  to  disintegrate  at  the 
cervical  margins  when  guarding  is  neglected. 

Mixing  and  Introducing  the  Cement. — As  a  preliminary  to  prepar- 
ing the  cement  for  introduction  into  the  prepared  cavity  the  rubber  dam 


342  OPERATIVE    DENTISTRY. 

should  be  adjusted,  in  order  that  perfect  dryness  of  the  cavity  may  be 
maintained  during  the  insertion  of  the  cement  and  the  early  stage  of  the 
hardening  or  setting  process. 

In  mixing  the  oxyphosphate  cement  one  or  more  drops  of  the  liquid, 
according  to  the  size  of  the  cavity  to  be  filled,  are  placed  upon  the  glass  mix- 
ing-slab, and  near  it  a  quantity  of  powder  ;  with  a  spatula  a  portion  of  the 
powder  is  then  drawn  into  the  liquid  and  mixed  by  rubbing  with  the  flat 
surface  of  the  spatula,  other  portions  being  added  a  little  at  a  time  until  a 
mass  is  formed  of  the  consistency  of  soft  dough,  the  surface  being  sticky 
or  tachj,  so  that  when  it  is  applied  to  the  dried  surface  of  the  cavity  it 
will  adhere  or  stick. 

Cements  which  are  made  so  hard  that  they  can  be  rolled  in  the  fingers 
have  not  given,  in  the  practice  of  the  writer,  as  good  clinical  results  either 
in  hardness  or  wearing  qualities  as  those  mixed  as  above  described. 

The  instruments  which  are  the  most  ai^plicable  for  the  introduction  and 
packing  of  the  oxyphosphate  cements  are  those  generally  used  for  intro- 
ducing amalgam  fillings,  the  spatula-shaped  instruments  being  the  most 
useful. 

If  the  mix  has  been  made  of  a  sticky  or  tacky  consistency,  the  final 
packing  of  the  filling  and  the  shai^ing  of  the  surface  will  be  more  readily 
accomplished  by  covering  the  surface  of  the  instrument  with  oil,  vaseline, 
or  glycerol,  to  prevent  the  material  from  sticking  to  it.  The  writer  pre- 
fers the  glycerol  for  the  reason  that  it  is  just  as  good  as  the  other  sub- 
stances for  preventing  the  material  from  clinging  to  the  instruments,  while 
it  has  the  advantage  of  not  leaving  an  unpleasant  taste  in  the  mouth. 

The  rubber  dam  should  not  be  removed  until  the  filling  has  set  suffi- 
ciently hard  to  j)ermit  of  finishing  the  surface.  The  finishing  may  be  ac- 
complished with  cuttle-fish  disks,  Arkansas  stones,  and  burnishers.  It 
has  generally  been  thought  that  the  process  of  crystallization  was  promoted 
by  protecting  the  filling  for  some  considerable  time  from  the  moisture  of 
the  mouth,  and  the  manufacturers  of  these  cements  usually  recommend 
covering  the  surface  of  the  filling  with  some  protecting  substance,  like 
sandarach  varnish,  or  burnishing  hot  wax  or  paraf&n  over  it.  The  utility 
of  such  a  procedure  would  seem  to  be  questionable  in  the  light  of  recent 
investigations  upon  the  cements,  conducted  by  Ames*  and  Wedelstaedt. 

Shrinkage  and  Expansion. — Ames  thinks  there  is  no  advantage  to 
be  gained  by  protecting  the  cement  fillings  for  an  indefinite  i)eriod  from 
the  saliva,  as  he  found  a  distinct  and  radical  difierence  in  the  amount  of 
shrinkage  when  the  two  classes  of  cements — viz.,  first,  those  modified  by 
alkaline  phosphates ;  and  second,  those  modified  by  non-alkaline  phos- 
phates— were  permitted  to  harden  in  a  dry  state  ;  but  when  the  process  of 
crystallization  was  allowed  to  take  iilace  with  the  mass  subjected  to  water 
there  was  a  marked  modification  of  the  amount  of  shrinkage,  which  was 
often  changed  to  expansion  in  the  second  class  of  cements. 

^'In  the  oxyphosphates  wherein  the  phosphoric  acid  has  been  modified 
by  alJcaUne  phosphates  only,  the  basic  phosphate  which  is  formed,  and  which 


'•  Dental  Cosmos,  1899. 


MANIPULATION  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      343 

accounts  for  the  hardening  of  the  mass,  is  of  a  friable  nature,  and  is  of 
itself  a  porous  material ;  so  that  in  agglomerating  the  crystals  or  granules 
of  the  zinc  oxide  it  exerts  no  s^DCcial  force  which  would  result  in  a  drawing 
together  of  the  granules  and  make  evident  a  shrinkage,  at  the  periphery. 

"  In  the  oxyphosphates  wherein  the  acid  has  been  modified  by  wow-alka- 
line phosphates,  the  basic  phosphate  formed  has  a  glassy  nature,  and  not 
only  agglomerates,  but  agglutinates  the  zinc  oxide  granules.  In  the 
previous  case  the  basic  phosphate  itself  becomes  porous  in  its  crystal- 
lization ;  while  in  the  second  case  it  is  a  glassy  material  which  agglu- 
tinates the  granules  to  such  an  extent  as  to  cause  a  drawing  of  them 
towards  a  centre  if  the  composition  happens  to  give  a  tendency  to  a 
diminution  of  volume  during  the  crystallization.  This  diminution  of 
volume  sometimes  dej)ends  on  a  lack  of  water  of  crystallization,  which 
if  present  in  the  composition  would  give  too  rapid  setting,  but  which  if 
added  to  the  crystallizing  or  hardening  mass  will  be  taken  up  and  give 
the  difference  between  a  shrinkage  and  zero  or  an  expansion. 

"In  the  first  there  is  a  diminution  of  volume  which  is  not  apparent, 
because  the  material  forms  a  porous  mass,  and  there  is  shrinkage  towards 
an  infinite  number  of  centres  instead  of  one,  as  in  the  second  class.  In  the 
second  class  there  may  be  diminution  of  volume  in  the  dry  state,  and  zero 
or  expansion  by  furnishing  extra  water  of  crystallization." 

Wedelstaedt*  in  his  investigations  was  surprised  to  find  "that  some  of 
his  experimental  fillings  of  oxyphosphate  would  expand  two  millimetres 
beyond  the  cavity  in  which  they  were  made,  and  was  equally  surprised  to 
find  shrinkage  in  some  cement  fillings  when  made  in  fresh  teeth  and  tested 
in  moisture.  The  aniline  ran  completely  around  the  filling,  leaving  the 
axial  wall  of  the  cavity  as  well  marked  as  though  no  cement  filling  had 
been  placed  in  that  cavity." 

Penetration  of  Moisture.— Wedelstaedtf  discovered  also  that  the 
oxyphosphate  cements  were  readily  penetrated  by  moisture,  as  was  proved 
by  the  fact  that  out  of  more  than  thirty  different  specimens  of  cements  only 
one  was  not  penetrated  from  circumference  to  centre  when  subjected  to  the 
aniline  test.  The  same  was  found  true  of  the  oxychlorides,  for  only  one 
sample,  "  Justi's  Acme,"  was  not  penetrated  by  moisture.  The  writer,  in 
conducting  a  similar  series  of  experiments,  found  but  one  form  of  zinc 
oxjqjhosphate  cement  that  was  impervious  to  aniline  dyes.  Specimen 
fillings  made  from  the  "Ames  Metaloid,"  after  being  immersed  in  aniline 
for  ten  days,  showed  no  penetration  either  at  the  margins  of  the  filling  or 
within  the  mass. 

Crushing  Stress. — Wedelstaedt  J  also  found  that  some  of  the  oxyphos- 
phate cements  would  sustain  a  surprising  amount  of  stress  when  thoroughly 
hardened,  and  that  age^  up  to  a  certain  point,  added  very  greatly  to  the 
strength  of  the  filling.  Six  fillings  were  made  in  cylinders  of  the  uniform 
size  of  two  and  a  half  by  three  and  a  half  millimetres,  and  all  made  from 
the  same  cement  and  from  one  mix.  These  were  tested  in  a  dynamometer, 
two  at  the  end  of  twenty-four  hours,  when  it  was  found  that  at  a  pressure 

*  Dental  Cosmos,  1899.  t  Ibid.  \  Ibid. 


344  OPERATIVE   DENTISTEY. 

of  from  eighty  to  ninety  pounds  they  crashed  to  pieces.  At  the  end  of 
forty-eight  hours  two  others  were  subjected  to  the  pressure  of  the  dyna- 
monieter,  and  sustained  a  stress  of  two  hundred  pounds  before  going  to 
pieces.  At  the  end  of  seventy-two  hours,  the  two  remaining  cylinders 
were  found  to  successfully  carry  a  weight  of  from  three  hundred  and  fifty 
to  ifoui-  hundred  pounds  before  crushing.  Other  fillings,  tested  ninety-six 
hours  after  they  were  made,  carried  over  four  hundred  pounds  of  stress 
before  going  to  pieces,  which  is  a  sustaining  strength  superior  to  that  of  the 
best-made  amalgam  or  gold  fillings.  The  best-made  fillings  of  the  former 
material,  according  to  Black,  crush  at  from  three  hundred  and  twenty- 
five  to  three  hundred  and  sixty  pounds  of  stress,  while  the  fillings  made 
from  the  latter  material  show  a  shortening  of  the  mass  under  a  stress  of 
three  hundred  and  fifty  pounds  of  from  two  to  fifteen  per  cent. 

Zinc  Oxysulphate. — This  x^reparation  is  in  no  sense  a  filling-material, 
but  it  is  a  valuable  adjunct  to  the  other  materials  for  protecting  and 
capping  pulps  which  are  nearly  exposed. 

Zinc  oxysulphate  is  composed  of  a  powder  consisting  of  one  part  of 
calcined  zinc  sulphate  to  two  or  three  x)arts  of  calcined  zinc  oxide.  The 
liquid  consists  of  a  solution  of  gum  arable  to  which  a  small  quantity  of 
calcium  sulphite  has  been  added.  The  powder  and  liquid  mixed  together 
form  a  mass  which  sets  quickly  and  attains  considerable  hardness.    (Flagg.) 

It  is  non-irritating  to  sensitive  dentin  and  to  exposed  pulps,  a  good 
non-conductor  of  caloric,  slightly  astringent,  and  seems  to  possess  a  pecu- 
liar conserving  action  ui^on  the  pulp  not  shared  to  an  equal  degree  by  any 
other  material  used  for  this  purpose. 

For  protecting  nearly  exposed  pulps  a  thin  paste  is  made  of  about  the 
thickness  of  cream,  which  is  carefully  flowed  over  the  bottom  of  the  cavity 
and  allowed  to  harden, — setting  takes  from  five  to  fifteen  minutes, — when  it 
should  be  covered  with  a  layer  of  oxyphosphate. 

In  capping  exposed  pulps  a  tiny  disk  of  writing-paper  or  other  suitable 
material  is  dipped  in  the  paste  and  quickly  and  carefully  laid  over  the 
exposure  and  covered  with  a  small  quantity  of  the  paste.  When  set  oxy- 
chloride  or  oxyphosphate  cement  may  be  placed  over  it  and  the  cavity 
lined  with  the  same  material,  preparatory  to  the  introduction  of  a  metal 
filling  or  a  porcelain  inlay. 

The  rubber  dam  should  invariably  be  used,  as  the  exclusion  of  all 
moisture  is  absolutely  necessary  to  the  success  of  the  operation. 

VARNISHES. 

Varnishes  are  often  used  for  lining  cavities  preparatory  to  the  introduc- 
tion of  the  plastic  fillings,  especially  of  the  zinc  oxychlorides  and  oxy- 
phosphates,  the  object  being  to  x>rotect  the  sensitive  dentin  and  the  pulp 
from  the  irritation  sometimes  induced  by  the  action  of  the  acids  contained 
in  the  liquids  of  these  compounds,  and  by  the  non-conducting  quality  of 
the  varnish  to  lessen  thermal  shock. 

These  varnishes  are  made  by  combining  certain  gums  and  resins  with 
alcohol,  chloroform,  and  ether,  such  as  gum  sandarach  in  alcohol,  virgin 
rubber  in  chloroform,   Canada  balsam,   copal,   or  dammar  in  ether,  and 


MAXIPULATIOX  AND  INTRODUCTION  OF  PLASTIC  FILLING-MATERIALS.      345 

trinitro-cellulose  in  methyl  alcohol.  These  solutions  should  be  made  thin 
enough  to  flow  readily,  and  be  applied  to  the  cavity  by  a  pellet  of  cotton. 

As  soon  as  the  varnish  has  dried  the  cement  lining  may  be  introduced, 
the  enamel  margins  having  first  been  freed  from  any  portion  of  varnish. 
The  same  precaution  must  be  observed  in  freeing  the  enamel  margins  of 
the  cement  before  the  permanant  filling-material  is  introduced,  as  careless- 
ness in  this  regard  is  bound,  sooner  or  later,  to  result  in  a  leaky  filling  from 
disintegration  of  the  film  of  varnish  or  of  the  cement  allowed  to  remain 
between  the  filling-material  and  the  enamel  margin. 

Some  operators  are  in  the  habit  of  lining  with  varnish  all  cavities  that 
are  to  be  filled  with  gold  or  amalgam,  claiming  for  this  method  that  it 
greatly  lessens  thermal  shock  by  sealing  the  open  ends  of  the  tubuli  and 
interposing  a  non-conducting  film  between  the  sensitive  dentin  and  the 
filling,  and  prevents  discoloration  when  amalgams  are  employed. 

The  same  method  is  pursued  by  these  operators  when  filling  with 
gutta-percha,  especially  when  employing  the  "high  heat"  material,  as  the 
adhesiveness  of  the  varnish  in  retaining  the  first  pellets  in  x^osition  is 
considered  an  added  advantage  of  the  varnish  lining. 


CHAPTER    XXI. 

INLAYS. 

Definition. — As  applied  to  deutal  surgery,  an  inlay  is  a  piece  of 
any  substance,  like  gold,  glass,  porcelain,  etc.,  which  is  inserted  in  a 
cavity  jjrepared  to  receive  it,  or  attached  to  a  portion  of  the  crown  of  a 
natural  tooth.  The  distinction  between  an  iyilay  and  a  filling  being  that 
the  inlay  is  inserted  into  the  cavity  in  a  solid  piece  and  retained  in  its 
l^osition  by  means  of  cement,  while  a  filling  is  introduced  in  numerous 
small  pieces,  which  either  cohere  or  weld  to  make  a  solid  mass,  or  are  held 
together  by  mechanical  pressure  or  the  interlacing  of  particles,  the  com- 
pleted filling  being  held  in  place  by  the  adaptation  of  the  material  to  the 
walls  of  the  cavity,  assisted  by  the  retentive  form  which  has  been  given 
to  it. 

The  dream  of  the  truly  scientific  and  artistic  dentist  has  always  been 
the  discovery  of  a  material  with  which  to  restore  those  portions  of  the 
natural  teeth  which  have  been  lost  bj^  the  disintegrating  effect  of  dental 
caries,  or  by  traumatic  injury,  that  would  be  indestructible  in  the  secre- 
tions of  the  oral  cavity,  protect  the  tooth  against  the  further  ravages  of 
caries,  restore  its  original  beauty  of  form,  color,  and  translucency,  and  at 
the  same  time  place  it  in  a  position  to  perform  all  of  its  functions  in  a 
normal  manner. 

The  art  of  the  porcelain- worker  has  already  reached  such  perfection  in 
the  construction  of  artificial  crowns  that  the  visible  portions  of  such 
restorations  are  so  natural  in  their  appearance  as  to  be  beyond  detection 
except  by  a  critical  examination. 

The  success  in  this  direction  has  stimulated  the  desire  to  successfully 
restore  by  the  same  means  such  portions  of  the  tooth  crown  as  have  been 
lost  by  disease  or  accident. 

In  studying  the  history  of  primitive  dental  art,  it  will  be  found  that 
the  idea  of  restoring  lost  portions  of  the  teeth  by  the  introduction  of 
inlays  is  as  old  as  the  art  itself  In  the  early  Greek  epoch,  teeth  were 
filled  with  metal  inlays  by  driving  solid  pieces  of  lead  into  the  cavity  ;  while 
doubtless  at  a  still  earlier  date  jade  or  graystone  was  used  for  the  same 
purpose,  as  found  in  the  central  incisors  of  the  skull  of  a  man  of  an 
extinct  race,  discovered  at  Copan,  Honduras,  by  Professor  Owen,  a  few 
years  ago,  and  which  is  now  to  be  seen  in  the  Peabody  Museum  of  Har- 
vard University. 

Inlays  made  of  various  materials  have  been  emi)loyed  by  the  modern 
dentist,  but  none  possess  in  so  high  a  degree  the  many  requisites  for  the 
ideal  filling  as  does  porcelain. 

Inlays  have  generally  been  used  in  two  classes  of  cavities  only,— viz., 
in  very  large  cavities  in  the  bicuspids  and  molars  the  walls  of  which  were 
too  frail  to  support  gold  fillings,  and  in  cavities  located  upon  the  labial 
346 


INLAYS. 


347 


surfaces  of  the  anterior  teeth  when  it  was  desirable  to  use  a  material  that 
would  be  less  conspicuous  than  gold,  and  which  would  harmonize  with  the 
color  of  the  tooth  in  which  it  was  inserted. 

Metal  Inlays. — Gold  has  been  recommended  for  making  inlays  for 
large  compound  cavities  in  the  bicuspids  and  molars,  and  is  still  used  for 
this  purpose  by  some  dentists  as  a  saving  of  time  and  strength  to  both 
operator  and  patient. 

These  inlays  are  made  in  two  ways.  One  by  swaging  gold  plate  over 
a  die  made  from  an  impression  taken  in  wax,  gutta-percha,  a  modelling 
compound,  or  by  burnishing  gold  or  platinum-foil  to  the  walls  and  margins 
of  the  cavity  ;  and  the  other  by  fusing  gold  into  a  matrix  made  in  sand 
and  plaster  mixed  with  asbestos  modelled  from  a  similar  impression.  The 
finished  inlay  is  then  cemented  into  place  with  zinc  oxyphosphate  cement 
or  gutta-percha.  In  order  to  secure  the  swaged  inlay  against  dislodge- 
ment  a  retaining  loop  should  be  soldered  to  its  under  side,  or  pins  may  be 
attached,  which  in  devitalized  teeth  may  be  made  to  enter  the  pulp-canals. 
The  fused  inlay  should  be  roughened  upon  the  surfaces  which  come  in  con- 
tact with  the  cement  for  the  same  purpose,  or  headed  pins  may  be  attached. 

Dr.  C.  L.  Alexander  describes  a  method  of  making  gold  inlays*  which 
has  many  good  features  and  may  frequently  be  applied  in  cases  when  the 
restoration  of  contour  by  the  means  of  porcelain  inlays  might,  on  account 
of  the  severe  strain  to  which  this  material  would  be  subjected,  and  its 
liability  under  sudden  and  excessive  stress  to  be  fractured,  be  of  question- 
able utility. 

The  method  is  equally  applicable  to  vital  and  pulpless  teeth.  In  the 
former,  anchorage  is  secured  by  short  posts  set  in  such  positions  as  not  to 
infringe  upon  the  pulp,  while  in  the  latter  the  pulp -canals  are  freely 
opened  and  longer  posts  so  set  as  to  penetrate  the  canals,  as  shown  at  A, 
Fig.  466,  the  tooth  being  prepared 
as  represented  at  A.  ^^^-  '^*^^- 

Platinum  plate,  No.  40  gauge, 
is  then  thoroughly  annealed  and 
a  piece  cut  from  it  of  proper  shape 
to  cover  the  lingual  surface  of  the 
crown  and  extend  over  the  mesial 
and  distal  surfaces.  This  is  bent 
into  shape,  fitted  to  its  place,  and 
a  hole  punched  in  it  over  the  open- 
ing to  the  pulp-canal ;  the  post  is 
then  passed  through  the  opening 
and  into  the  pulp-canal,  being  long 
enough  to  project  a  little  distance 
beyond  the  outer  surface  of  the 
plate.  A  small  piece  of  soft  modelling  compound  is  then  moitlded  over 
the  plate  and  the  projecting  end  of  the  post,  which  when  hardened  holds 
them  in  their  relative  positions.     The  piece  is  then  invested  in  sand  and 


Showing  details  of  the  process  for  making  cast  fill- 
ing for  incisor.  (After  C.  L.  Alexander.)  A,  post  with 
plate  adapted  ;  B,  restored  contour  in  wax  ;  C,  the 
contour  invested ;  D,  cast  contour  detached  ;  E,  E, 
the  finished  restoration. 


*  Dental  Cosmos,  October,  1896. 


348 


OPERATIVE    DENTISTRY. 


plaster,  and  the  post  soldered  to  the  plate  with  pure  gold.  It  is  then 
returned  to  the  tooth,  the  platinum  plate  carefully  burnished  to  the  surface 
of  the  crown,  and  the  edges  are  trimmed  to  the  desired  shape.  An  im- 
pression and  bite  are  next  taken  as  for  making  a  crown  and  set  up  in  an 
articulator  with  sand  and  plaster.  After  removing  the  modelling  com- 
pound the  contour  of  the  tooth  is  restored  in  hard  wax  upon  the  platinum 
base.  A  piece  of  No.  60  gold-foil  or  platinum-foil  is  then  burnished  over 
the  wax,  covering  it  except  at  one  wall,  preferably  the  lingual  surface. 
The  whole  tooth  is  then  cut  from  the  model  and  invested,  care  being  taken 
to  completely  cover  it  except  at  the  surface  of  wax  not  covered  with  the 

foil.      When  hardened  the  wax 


Fig.  467. 


Fig.  468. 


is  boiled  out,  leaving  the  metal 
lining  the  matrix,  which  acts  as 
a  carrier  for  tiie:  metal  which  is 
to  be  fused  into  it.  The  matrix 
is  then  fluxed,  filled  with  pieces 
of  twenty  -  two  -  carat  solder, 
and  the  investment  thoroughly 
heated,  when  with  a  fine  blow- 
pipe flame  directed  into  the 
matrix  the  solder  is  flowed, 
more  being  added  until  the 
matrix  is  full.  After  it  is  re- 
moved from  the  investment  the 

casting  is  finished  and  cemented  into  its  position  ;  the  final  polishing  to  be 

done  after  the  cement  has  thoroughly  set. 

Fig.  467  shows  the  method  of  restoring  a  raesio-morsal  angle  in  a  vital 

tooth.     Fig,  468  shows  the  restoration  of  the  lingual  cusp  and  morsal  sur- 


Restoration  of  incisor  by  RestxDration  of  molar 

cast  filling.  by  cast  filling. 

(After  (;.  L.  Alexander.) 


Fig.  469, 

flBUll 


Fig.  470. 


Front  and  back  ^n'ews  of  an  incisor  restoration  and 
cast  tilling  for  molar.    (After  C.  L.  Alexander.) 


Foil  matrix  invested.    Cast  filling  for 
molar.    (After  C.  L.  Alexander.) 


face  of  a  devitalized  bicusj)id.  Fig.  469  gives  a  labial  and  a  lingual  view 
of  incisor  restoration  and  cast  filling  for  molar  as  adajjled  to  vital  teeth. 
Fig.  470  shows  a  more  extensive  restoration  of  a  molar  tooth.  This  method 
may  also  be  adapted  to  the  making  of  abutments  for  carrying  pieces  of 
bridge-work,  as  shown  in  Figs.  471  and  472. 

Amalgam  inlays  were  quite  extensively  used  a  few  years  ago  in  Ger- 
many for  restoring  the  contour  of  the  posterior  teeth.     These  were  fur- 


INLAYS. 


349 


nished  by  the  dealers  in  several  different  shapes  and  sizes,  and  were  set  in 
position  by  means  of  freshly  prepared  soft  amalgam.  The  only  advantage 
of  amalgam  inlays  is  the  ease  with  which  they  are  made,  but  aside  from 


Fig.  471. 


Fig.  472. 


Method  of  bridging  with  inclined  abutment. 
(After  C.  L.  Alexander.) 


Bridge  with  cast  filling  abutments.    (After  C.  L. 
Alexander.) 


this  they  have  nothing  to  recommend  them,  and  are  in  no  respect  as  good 
as  amalgam  fillings  made  in  the  usual  waj'. 

Porcelain  Inlays. — Porcelain  is  the  only  material  which  has  so  far 
been  discovered  that  can  be  made  to  imitate  natural  tooth-structure,  and 
this  art,  in  the  manufacture  of  artificial  teeth,  has  been  carried  to  such 
perfection  that  when  proj)erly  arranged  and  mounted  they  are  capable  of 
deceiving  any  one  who  is  not  a  professional  expert  in  the  art.  For  this 
reason  the  artistic  dentist  has  always  looked  forward  to  the  time  when  por- 
celain could  be  substituted  for  gold  and  amalgam  in  filling  teeth  in  the 
anterior  j)art  of  the  mouth  and  in  conspicuous  locations  in  the  bicuspids 
and  molars. 

Various  efforts  have  been  made  in  the  past  to  introduce  porcelain  as  a 
material  for  filling  teeth,  but  tlie  difaculties  which  have  always,  until  very 
lately,  surrounded  the  operation  have  deterred  all  but  a  very  few  practi- 
tioners from  attempting  the  task. 

The  earliest  method  of  using  porcelain  as  a  filling  for  decayed  teeth  was 
to  prepare  the  cavity— usually  in  the  labial  surface  of  an  anterior  tooth — 
with  slightly  flaring  walls  or  bevelled  margins,  and  then  to  grind  a  piece 
of  a  porcelain  tooth  having  a  color  that  would  match  that  of  the  tooth  in 
which  the  inlay  was  to  be  inserted  until  it  would  fit  the  cavity,  and  re- 
taining it  in  situ  with  zinc  oxychloride  cement,  or  by  packing  gold  around 
the  edges.  The  writer  has  seen  one  such  inlay,  which  was  inserted  by  the 
late  Dr.  W.  W.  Allport,  that  had  done  service  for  more  than  thirty  years, 
and  was  still  as  perfect  as  upon  the  day  in  which  it  was  completed.  The 
method  of  grinding  adopted  by  the  earlier  operators  was  to  smear  the 
margin  of  the  cavity  with  a  water-color,  generally  red,  and  then  to  place 


350 


OPERATIVE    DENTISTRY. 


the  inluy  in  Uie  cavity,  and  after  removing  it  grind  those  places  which  had 
received  the  color  as  is  practised  in  grinding  gum  sections  to  fit  the  rim 
of  a  gold  i)late. 

Another  and  perhaps  better  method  of  fitting  such  inlays  is  to  take 
an  impression  of  the  margin  of  the  cavity—after  it  has  been  prepared  to 
receive  tile  inlay— with  a  piece  of  No.  20  tin-foil,  by  placing  it  over  the 
cavity  and  with  a  soft  rubber  eraser  or  a  rubber  bottle-stopper  pressing 
the  foil  firmly  until  the  margin  is  sharply  marked.  This  impression 
should  then  be  carefully  trimmed  to  the  line  of  the  cavity  margin,  and  the 
pattern  glued  to  the  upper  surface  of  the  piece  of  porcelain  tooth  that 
is  to  become  the  inlay  to  serve  as  a  guide  in  the  grinding.  The  section 
should  be  cemented  with  shellac  to  a  piece  of  wood  on  its  under  surface  to 
assist  in  holding  it  during  the  process  of  grinding.  With  care,  patience, 
and  unlimited  time  at  the  disposal  of  the  operator  a  perfect  fit  may  be 

Fig.  473.  Fig.  474. 

Q  ©  00 

Porcelain  stoppers. 

obtained,  but  only  after  repeatedly 
trying  the  inlay  in  the  cavity.  The 
final  fitting  of  the  inlay  may  be  ex- 
pedited by  cementing  with  shellac  the 
end  of  a  short  section  of  wire  or  a 
broken  excavator  handle  to  its  upper 
surface,  as  this  overcomes  the  difficulty 

in  holding  the  section  during  the  pro-  jj^i^y  ^.^^^ 

cess  of  grinding,  and  offers  a  ready 

means  of  inserting  and  removing  the  section  from  the  cavity.  The  time 
consumed  in  this  process  of  fitting  inlays  is  so  great  that  few  people  are 
willing  to  sufficiently  remunerate  the  dentist  to  make  it  a  profitable  or 
popular  operation. 

As  a  means  of  overcoming  some  of  the  difficulties  attending  this  great 
time-consuming  operation  the  dental  porcelain  manufacturers  have  placed 
upon  the  market  ready-made  porcelain  inlays  of  different  shapes,  sizes, 
and  colors,  known  as  porcelain  stoppers  (Fig.  473).  These  stoppers  can- 
not be  used  until  they  are  ground  to  fit  the  cavity,  which  may  be  done  after 
the  manner  just  described. 

Another  method  is  that  devised  by  Dr.  G.  H.  Weagant,  which  consists 
of  cutting  inlays  from  artificial  teeth  or  inlay  rods  (Fig.  474)  by  the  aid 
of  especially  devised  trephines  of  five  different  sizes  (Fig.  475),  made  of 
copper  and  charged  with  diamond  dust. 

These  trephines  are  to  be  used  in  conjunction  with  How's  inlay  burs 
(Fig.  476),  which  correspond  in  size  to  the  trephines. 

After  the  decay  has  been  removed  from  the  cavity,  a  bur  is  selected 
from  the  How  set  which  will  be  large  enough  to  include  the  utmost  limits 
of  the  cavity,  and  the  final  preparation  of  the  cavity  completed  with  it. 
A  trephine  is  next  selected  which  corresponds  in  size  with  the  How  bur. 
and  a  section  cut  from  an  artificial  tooth,  preferably  of  English  make, 


INLAYS. 


!51 


whose  color  matches  that  of  the  natural  tooth.  This  inlay  is  then 
cemented  w  sihi  with  zinc  oxyphosphate,  and  after  the  cement  has  set 
any  projection  of  the  inlay  may  be  dressed  off  with  fine  Arkansas  stones, 
or  diamond  disks  or  burs.     If  English  artificial  teeth  are  used,  or  those  of 


Fig.  475. 


Fig.  476. 


^\■eagaut  trephines. 


11 
How  inlay  burs, 


the  Consolidated  Dental  Manufacturing  Company,  the  inlay  will  receive  a 
fine  polish^  and,  not  being  of  porous  material,  it  will  show  no  tendency  to 
discoloration.  This  method  is,  however,  open  to  one  very  serious  objec- 
tion,— viz,,  the  necessity  of  sacrificing  a  large  amount  of  sound  dental 
tissue  in  order  to  give  a  circular  outline  to  the  walls  of  the  cavity.  For 
this  reason,  principally,  the  method  has  never  been  employed  to  any  great 
extent. 

A  very  beautiful  and  close  joint  may  be  made  by  this  method  if 
the  joint  is  ground  while  the  inlay  is  in  situ.  This  may  be  accom- 
plished by  cutting  the  inlay  a  size  larger  than  the  cavity  which  is  to 
receive  it,  and  slightly  tapering  the  section  until  the  lower  end  will  freely 
enter  the  margins  of  the  cavity.  It  may  then  be  cemented  to  an  engine 
mandrel,  and  ground  into  place  by  revolving  it  in  the  cavity,  using  pul- 
verized pumice  moistened  with  water  as  the  grinding  medium,  just  as  the 
plumber  grinds  the  joint  of  a  water-cock. 

Glass  Inlays. — Herbst,  of  Bremen,  in  1887,  introduced  a  system  of 
making  inlays  by  fusing  powdered  glass  in  a  matrix  of  platinum-gold  foil, 
made  by  pressing  the  foil  into  the  prepared  cavity  with  pellets  of  cotton 
and  burnishing  it  to  the  margins. 

The  powdered  glass,  which  was  made  from  Venetian  glass  beads,  and 
sold  under  the  names  of  "Eichter's  Glasmasse"  (glass-body)  and  Meyer's 
and  Herbst' s  Venetian  Enamel,  was  furnished  by  the  dealers  in  several 
shades,  so  that  it  was  possible  with  care  to  match  the  color  of  the  natural 
teeth  fairly  well,  and  when  the  inlay  was  cemented  in  situ  it  presented  an 
appearance  which  very  closely  imitated  the  vitreous  surface  of  the  enamel. 

The  method  of  fusing  the  glass  was  to  hold  the  matrix,  which  had  been 
filled  with  the  material,  in  the  flame  of  a  Bunsen  burner  or  alcohol  lamp. 
In  order  to  render  the  glass  fusible  at  so  low  a  degree  of  heat  it  was  neces- 
sary to  reduce  the  melting-point  by  the  introduction  of  a  large  amount  of 
flux.  This  rendered  the  material  soft  and  porous,  so  that  it  was  unable  to 
withstand  the  action  of  the  oral  secretions  or  the  attrition  of  mastication, 
and  soon  lost  its  satisfactory  appearance,  first  becoming  opaque,  then  dis- 


352 


OPERATIVE    DENTISTRY. 


colored,  and  later  almost  black,  while  the  surfaces  which  came  in  contact 
with  occluding  teeth  disintegrated  and  wore  away  like  zinc  phosphate 
cement. 

Tlie  invention  of  thjp  metalic  matrix  by  Dr.  William  Eollins,  of  Boston, 
and  described  by  him  in  a  paper  read  before  the  Society  for  the  Advance- 
ment of  Oral  Science,  June,  1880,  though  almost  forgotten  for  nearly  two 
decades,  has,  nevertheless,  the  enviable  distinction  of  having  led  the  way 
to,  and  made  possible  the  construction  of,  artistic  and  perfect  fitting  porce- 
lain inlays. 

Another  important  step  towards  the  perfection  of  this  process  was  the 
invention  by  Dr.  C.  H.  Land,  in  1884,  of  the  gas  furnace.  Before  this 
time  the  dentist  who  desired  to  make  a  porcelain  inlay  by  fusing  the  mate- 
rial in  a  metal  matrix  was  hampered  in  his  work  by  being  obliged  to 
depend  upon  the  slow-heating  and  cumbersome  coke  furnace. 

This  invention  was  followed  by  the  Downie  crown  furnace,  which  was 
still  smaller  than  the  Land  furnace,  and  later  by  the  electric  oven  of 
Custer  and  the  electric  furnace  of  Mitchell  (Figs.  477  and  478). 

Since  the  introduction  of  electricity  as  a  means  of  heating  furnaces  for 
the  firing  of  porcelain  the  size  of  the  apparatus  has  been  greatly  reduced, 
and  the  time  consumed  in  heating  the  furnace  and  firing  the  porcelain  has 


FiQ.  477. 


FiQ.  478. 


Custer  electric  oven. 


Mitchell  tlcttrii  furnace 


been  curtailed  to  a  few  minutes,  while  the  danger  from  changing  the  color 
of  the  material  by  the  presence  of  gases  has  ceased  to  cause  anxiety,  and 
the  noise,  dirt,  and  hard  labor  incident  to  working  the  foot-bellows  of  the 
gas  furnace  have  all  been  done  away  with. 

Porcelain.— Until  quite  recently  the  porcelain  used  for  making  inlays 
was  of  the  high-fusing  grade,  the  Close  or  Downie  porcelain  body  generally 
being  employed.  These  bodies  require  a  platinum  matrix  in  which  to  fuse 
them,  as  the  fnsing-point  is  about  2500°  F.,  which  is  considerably  higher 
than  the  fusing-poiut  of  pure  gold. 


INLAYS.  353 

The  Downie  bodies  are  furnislied  in  twenty- four  different  shades  of 
color,  which  makes  it  possible,  when  skilfully  and  artistically  combined,  to 
reproduce  any  shade  of  color  to  be  found  in  the  natural  teeth.  These 
porcelains  are  admirably  adax)ted  for  crown-  and  bridge- work,  but  they 
have  never  been  extensively  used  for  inlays,  for  the  reason  that  a  platinum 
matrix  is  I'equired  in  which  to  fuse  them,  and  this  material  is  so  stiff  and 
harsh,  even  when  annealed  in  a  furnace,  that  it  cannot  be  readily  adapted 
to  the  cavity  walls  and  margins,  and  therefore  does  not  furnish  so  reliable 
a  means  of  taking  an  impression  of  the  cavity  as  does  gold-foil,  and  fail- 
ures in  the  fit  of  the  inlay  are  more  liable  to  occur.  For  this  reason  vari- 
ous efforts  have  been  made  to  produce  a  low-fusing  porcelain  that  could  be 
fired  in  a  gold-foil  matrix,  and  which  at  the  same  time  would  not  be  po- 
rous, would  not  change  its  color  in  firing,  would  be  susceptible  of  taking 
a  polish  after  being  ground,  would  not  disintegrate  or  change  its  color  in 
the  mouth,  and  would  have  sufficient  strength  to  withstand  the  stress  of 
mastication. 

For  several  years  Dr.  E".  S.  Jenkins,  an  American  dentist,  of  Dresden, 
Germany,  experimented  with  porcelain,  and  consulted  the  best  chemists 
and  expert  porcelain-  and  glass- workers  of  Europe  in  an  endeavor  to  iDer- 
fect  a  low-fusing  porcelain  which  would  fulfil  the  requirement  of  the  den- 
tal practitioner  for  inlay  work.  In  March,  1898,  he  announced  to  the 
members  of  the  American  Dental  Society  of  Europe — before  whom  he 
had  frequently  discussed  the  question  of  porcelain  inlays,  and  had  re- 
13orted  from  time  to  time  the  i^rogress  of  his  exiDerimeuts — that  he  had 
finally  succeeded  in  his  undertaking ;  that  he  could  now  pronounce  his  work 
finished,  and  desired  first  to  announce  his  discovery  to  them,  and  then  to 
the  profession  at  large.  The  announcement  attracted  universal  attention, 
and  dentists  everywhere,  both  in  Europe  and  America,  began  experiment- 
ing with  Jenkins' s  porcelain  enamels  and  his  method  of  making  inlays. 

These  porcelains  are  very  finely  ground,  and  are  furnished  to  the  pro- 
fession in  eighteen  different  color  shades,  whites,  blues,  yellows,  and 
browns.  Dr.  Jenkins  says  of  his  porcelain  enamel,  that  he  took  as  his 
model  the  Ash  &  Son's  tooth,  and  tried  as  far  as  jDOSsible  to  imitate  the 
fine  texture  and  character  of  this  porcelain  tooth  body,  but  so  changed  its 
composition  as  to  make  it  fuse  at  a  degree  of  heat  which  would  allow  of 
its  being  fired  in  a  gold-foil  matrix.  Great  difficulty  was  experienced  in 
obtaining  colors  which  would  not  change  during  the  process  of  firing,  but 
he  finally  succeeded,  so  that  there  is  absolutely  no  change  at  any  degree 
of  heat  which  will  not  melt  the  gold-foil  matrix. 

The  permanency  of  the  color  in  the  fluids  of  the  mouth  he  believes 
is  scientifically  certain  ;  the  material  is  not  acted  upon  by  any  chemic 
substance  except  hydrofluoric  acid,  and  is  so  hard  and  tough  that  it  will 
withstand  the  stress  brought  upon  it  in  mastication  without  appreciable 
attrition  or  chipping,  and  retain  its  polish  under  the  use  of  the  tooth-brush 
and  powder. 

Ash  &  Son,  of  London,  have  j^erfected  a  high-fusing  body  in  six 
shades,  with  two  shades  of  enamel,  one  dark,  the  other  light,  which 
Dr.  J.  Leon  Williams  very  highly  recommends  in  an  article  on  '^  Ceramic 

23 


354  OPERATIVE    DENTISTRY. 

Art  in  Eestoration  of  Teeth"  (Dental  Cosmos,  Kovember^  1899).  They 
Lave  also  prepared  a  low-fusing  body  in  seven  colors,  and  one  enamel, 
which  he  tliinks  are  in  no  way  inferior  to  those  prepared  by  Dr.  Jenkins. 

The  Consolidated  Dental  Manufacturing  Company  of  l^ew  York  have 
also  prepared  and  placed  upon  the  market  high-fusing  and  low-fusing 
porcelains  made  after  suggestions  of  Dr.  Joseph  Head,  which  seem  to  be 
in  every  way  equal  to  the  Jenkins  and  Ash  bodies. 

METHODS   OF   MANIPULATION. 

The  first  important  consideration  in  making  porcelain  inlays  is  a 
Judicious  selection  of  the  cases  in  which  this  method  of  filling  teeth  is  to  be 
employed.  It  is  not,  for  instance,  applicable  to  cavities  in  the  distal  sur- 
faces of  the  second  and  third  molars,  for  the  reason  that  in  such  locations 
a  perfect  impression  would  be  difficult  or  well-nigh  impossible  to  obtain, 
and  consequently  an  inlay  could  not  be  constructed  which  would  be  as 
good  as  a  metal  filling  inserted  in  the  usual  manner.  In  all  other  locations 
in  the  mouth,  with  skill  and  patience,  satisfactory  inlays  may  be  inserted. 

The  locations,  however,  in  which  they  are  most  applicable  are  : 

1.  In  cavities  upon  the  labial  and  buccal  surfaces  of  the  incisors,  cus- 
pids, and  bicuspids. 

2.  In  large  cavities  located  upon  the  approximal  surfaces  of  the  six 
anterior  teeth  and  the  mesial  surfaces  of  the  bicuspids. 

3.  In  large  cavities  involving  the  mesio-morsal  surfaces  of  the  first 
molars. 

4.  In  large  morsal  cavities  in  any  of  the  molars  when  the  walls  are 
thin  and  the  pulp  nearly  exposed. 

One  of  the  great  advantages  of  porcelain  as  a  material  for  stopping  carious 
teeth  is  its  low  conducting  power  of  caloric,  which  greatly  lessens  the  shock 
incident  to  the  sudden  changes  of  temperature  so  constantly  taking  place 
in  the  mouth,  and  which  sometimes  makes  a  metal  filling  unendurable. 

Preparation  of  the  Cavity. — In  j)i"eparing  a  cavity  to  receive  a 
porcelain  inlay,  the  same  degree  of  care  should  be  exercised  in  removing 
the  decayed  and  infected  dentin  that  would  be  expended  upon  it  if  it  was 
to  receive  a  gold  filling. 

The  shaping  of  the  cavity  is  an  important  feature,  and  too  much  care 
cannot  be  expended  upon  it.  In  general  terms  it  may  be  stated  that  the 
cavity  should  be  formed  with  flaring  walls — in  other  words,  cui^-shaped — 
without  undercuts,  and  the  enamel  margins  slightly  bevelled  outward,  so 
that  when  the  foil  is  removed  and  the  inlay  is  inserted  it  will  set  into  the 
cavity  the  thickness  of  the  matrix  and  fit  tightly  at  the  margins. 

In  preparing  the  enamel  margins  all  corners  and  sharp  angles  must  be 
removed,  the  outline  of  the  cavity  following  graceful  curves.  The  bevel 
must  not  be  too  great,  as  this  would  give  a  thin  edge  to  the  inlay  and 
might  cause  it  to  chip.  In  restoring  a  mesio-morsal  or  disto- morsal  angle 
of  an  incisor,  it  is  best  to  leave  the  margin  square  at  a  right  angle  to  the 
morsal  edge,  as  by  this  method  there  is  less  danger  of  the  enamel  edge 
being  fractured.  The  margins  of  all  morsal  cavities  should  be  prepared 
in  the  same  manner. 


INLAYS.  355 

Preliminary  separation  of  the  teeth  is  an  essential  in  inlay  work,  as 
plenty  of  space  must  be  secured  if  a  perfect  impression  is  to  be  obtained 
and  the  normal  contour  restored. 

Taking  the  Impression. — A  perfect  impression  is  a  sine  qua  non, 
without  which  every  effort  at  making  a  perfect  fitting  inlay  will  prove 
futile. 

The  materials  which  are  employed  for  this  purpose  are  platinum-  and 
gold-foils,  platinum  IsTo.  30  being  used  for  high-fusing  bodies,  and  gold 
IS"©.  30,  and  occasionally  No.  40,  for  low-fusing  bodies. 

Several  methods  have  been  suggested  for  taking  impressions  of  cavities 
in  teeth  which  are  to  be  filled  with  porcelain  inlays.  The  simplest  is  to 
cut  a  piece  of  foil  a  little  larger  than  the  cavity  of  which  an  impression  is 
desired — if  j)latinum-foil  is  used,  this  should  be  thoroughly  annealed  in  a 
furnace  for  several  minutes  and  allowed  to  cool  slowly — and  j)lace  it  over 
the  cavity,  and  then  with  a  ball  of  cotton,  bibulous  paper,  or  amadou, 
held  in  a  pair  of  slender  curved  foil-carriers,  gently  press  the  foil  into 
apiDOsition  with  the  walls  of  the  cavity,  smoothing  out  the  wrinkles 
towards  the  margins,  l^ext  pack  the  cavity  with  small  pieces  of  amadou, 
holding  them  in  position  with  an  instrument  held  in  the  left  hand,  while 
with  a  ball-burnisher  the  enamel  margins  are  well  defined.  The  amadou 
is  then  removed,  and  the  foil  matrix  jarred  out  of  the  cavity  by  tapping 
the  tooth  with  the  foil-carrier,  or  by  carefully  teasing  it  out  with  a  curved 
pointed  explorer.  Sometimes  the  matrix  will  come  away  with  the  amadou 
packing,  but  if  it  has  to  be  removed  by  the  means  just  suggested,  a  small 
receptacle  should  be  held  under  the  tooth  to  receive  it  when  it  falls.  A 
small  sugar-spoon  or  a  small  pill-box  will  answer  the  purpose.  The 
suri^lus  foil  is  then  trimmed  off  a  little  distance  from  the  line  of  the 
enamel  margin,  and  the  matrix  returned  to  the  cavity  and  moulded  as 
before.  The  greatest  of  care  must  be  exercised  not  to  change  the  shape  of 
the  matrix  after  it  finally  leaves  the  cavity.  For  this  reason  some  opera- 
tors recommend  investing  the  matrix  in  sand  and  plaster,  or  in  powdered 
asbestos  and  plaster.  The  writer  combines  the  latter  materials  in  equal 
parts,  which  form  a  sufficiently  firm  and  stable  investment  for  the  j)ur- 
pose.  The  investing  material  should  be  mixed  quite  soft,  so  that  when 
the  matrix  is  laid  upon  its  surface  it  will  embed  itself  up  to  the  described 
margins  of  the  cavity. 

Some  operators  think  the  platinum  matrix  is  sufBcieutly  rigid  after 
being  fitted  to  the  cavity  to  need  no  supporting  investment,  and  this  is 
doubtless  true  when  heavy  foil  is  used,  but  not  so  with  light-weight  foil, 
and  in  any  case  the  investment  removes  the  anxiety  of  its  becoming 
changed  in  form,  and  also  insures  a  perfect  fit  if  it  has  not  been  altered 
before  it  is  invested.  As  soon  as  the  investment  is  dry  the  matrix  is 
ready  to  receive  the  porcelain  body. 

Another  method  is  to  fill  the  matrix  with  moderately  hard  wax  or  gutta- 
percha before  removing  it  from  the  cavity,  and  then,  turning  it  bottom  side 
up,  invest  it.  After  the  investment  has  hardened,  the  wax  or  gutta-percha 
is  removed  by  boiling  water. 

The  same  methods  are  employed  for  taking  an  im^Dression  with  gold- 


356  OPERATIVE   DENTISTRY, 

foil,  but  greater  care  is  necessary  in  removing  the  matrix  not  to  alter  its 
shape.  Gold- foil,  however,  has  the  advantage  over  platinum  that  it  gives 
a  sharper  impression  of  the  walls  and  margins  of  the  cavity,  and  therefore 
insures  a  more  perfect  fit.  A  tear  in  the  foil  at  the  bottom  of  the  cavity 
is  of  no  consequence,  as  the  body  will  not  pass  through  it,  but  a  tear  oc- 
curring at  the  margin  ruins  the  fit  of  the  inlay. 

Dr.  Jenkins  recommends  investing  the  gold-foil  matrix  in  simple  pow- 
dered asbestos  mixed  with  water  to  a  thick  creamy  paste.  This  investment 
will  be  found  to  be  sufficiently  strong  for  the  purpose,  and  it  can  be  fired 
any  number  of  times  without  cracking.  As  soon  as  the  investment  has 
been  dried— and  this  should  be  done  slowly — the  matrix  is  ready  to  receive 
the'body. 

Dr.  Van  Woert  recommends  taking  an  impression  with  inlay  cement, 
such  as  that  manufactured  by  the  Consolidated  Dental  Manufacturing  Com- 
pany. The  method  is  as  follows  :  Mix  the  cement  to  a  stiff  paste  that  can 
be  manipulated  with  the  fingers,  press  it  into  the  cavity, —which  has  been 
previously  anointed  with  vaseline, — and  allow  it  to  harden,  care  being 
taken  to  use  a  mass  sufficient  to  overhang  the  cavity  margins  in  all  direc- 
tions. When  hard,  trim  sufficiently  to  allow  it  to  be  removed  from  the 
cavity  without  fracturing  it.  It  is  then  embedded  in  a  piece  of  warm  model- 
ling compound  with  the  impression  of  the  cavity  uppermost  and  the  edges 
free.  Then  cool  in  ice-water,  and  make  a  counter-die  of  the  cement  im- 
pression in  softened  modelling  compound.  When  cooled,  this  will  be 
found  sufficiently  hard  to  permit  of  swaging  No.  30  gold-foil  to  the  exact 
shape  of  the  cavity  in  the  tooth.  The  matrix  thus  fashioned  is  to  be  re- 
moved and  invested  in  moistened  powdered  asbestos  as  above  described. 
Dr.  Van  Woert  claims  for  this  method  a  more  perfect  fit,  inasmuch  as  the 
matrix  was  made  over  a  die  which  gives  the  exact  outline  measurements 
of  the  cavity,  and  does  not  leave  a  deficiency  equal  to  the  thickness  of  the 
matrix. 

Packing  the  Body  and  Firing. — The  selection  of  the  color  for  the 
inlay  must  be  done  with  the  shade  ring  which  accompanies  the  porcelain 
powders,  and  with  the  tooth  in  the  moist  state.  Drying  a  tooth  changes 
its  color  very  materially.  The  writer  selects  a  porcelain  tooth  that  matches 
the  color  of  the  tooth  to  be  filled,  and  uses  this  as  a  guide  while  baking 
the  inlay.  First  ascertain  the  basal  color,  and  then  any  tone  may  be  given 
to  it  by  a  proper  combination  of  the  other  colors. 

The  body  may  be  mixed  either  with  distilled  water  or  absolute  alcohol. 
In  mixing  the  body  a  consistency  of  soft  dough  should  be  obtained.  It  is 
then  placed  in  the  matrix  with  a  small  spatula,  and  settled  into  place  by 
tapping  the  pliers  that  hold  the  platinum  matrix  or  the  tray  containing  the 
invested  gold  matrix.  In  packing  the  first  instalment  of  the  body  it 
should  not  be  allowed  to  come  quite  up  to  the  margins  of  the  matrix.  If 
the  matrix  is  filled  at  the  first  firing,  the  contraction  of  the  material  is 
very  likely  to  warp  the  matrix  and  spoil  the  fit  of  the  inlay.  This  is  now 
placed  in  the  furnace  and  fired  until  a  glaze  appears  upon  the  surface,  when 
it  is  removed,  cooled,  and  returned  to  the  cavity,  and  the  edges  again  care- 
fully burnished  to  the  margins. 


INLAYS.  357 

The  partially  filled  matrix  is  again  removed  and,  if  of  gold,  invested  as 
before,  and  the  second  instalment  of  body  added  to  that  already  fired, 
bringing  it  U])  to  the  edges  and  giving  it  the  desired  contour,  but  care- 
fully removing  with  a  camel' s-hair  pencil  any  portion  of  body  which  may 
have  projected  beyond  the  line  of  the  enamel  margins,  when  it  is  again 
fired.  It  is  a  safe  plan  to  replace  the  inlay  in  the  cavity  after  the  second 
firing  and  study  its  contour  ;  if  this  is  not  quite  right,  more  material  can 
be  added  and  the  piece  again  fired. 

After  the  inlay  has  cooled  the  foil  matrix  may  be  peeled  off  by  starting 
it  from  the  edges  first  and  working  towards  the  centre.  If  it  is  peeled 
towards  the  edges,  chipping  is  likely  to  occur.  Any  particles  of  the  foil 
which  remain  may  be  scraped  off  with  an  excavator,  and  it  is  imjDortant 
that  all  be  removed,  or  a  perfect  fit  of  the  inlay  will  not  be  secured. 

In  building  large  contours  or  restoring  the  angle  of  an  incisor,  a  chip 
of  a  porcelain  tooth  of  the  jiroper  color  may  be  placed  in  the  matrix  and 
the  body  built  around  it.  Such  cases,  however,  require  to  be  heated  and 
cooled  more  slowly  than  small  inlays,  or  otherwise  there  is  danger,  from  the 
sudden  expansion  and  contraction,  of  cracking  and  checking  the  piece. 

A  safe  rule  to  follow  is  to  make  all  inlays  a  trifle  darker  tlian  the  tooth 
when  inserting  them  in  the  labial  and  buccal  surfaces  or  the  approximal 
surfaces  of  the  incisors,  as  they  are  less  conspicuous  if  a  little  darker  than 
when  a  little  lighter.  In  approximal  cavities  in  the  bicuspids  and  molars 
lying  well  in  the  shadow  of  the  tooth  the  inlay  should  be  a  trifle  lighter 
in  shade  than  the  tooth,  as  the  shadow  makes  them  appear  darker. 

Williams  suggests  that  the  contraction  which  occurs  in  firing  large 
inlays,  which  often  warps  the  matrix  and  thus  destroys  the  accuracy  of  the 
fit,  may  be  obviated  by  mixing  the  porcelain  paste  to  the  consistency  of 
soft  putty,  and  building  a  '"'ring  of  this  putty  around  the  entire  circumference 
of  the  cavity  in  the  matrix,  leaving  the  centre  free  and  empty.  In  melting  a 
porcelain  paste  it  naturally  shrinks  towards  the  largest  mass  of  its  own 
body,  or  towards  the  centre  of  the  mass.  If,  then,  this  centre  be  removed, 
we  should  naturally  expect  the  mass  to  shrink  towards  the  circumference,  and 
this  is  precisely  what  happens  when  manipulated  as  directed.  The  matrix 
always  comes  out  from  the  first  baking  with  the  porcelain  everywhere 
firmly  melted  to  the  walls  of  the  matrix.  ISTor  will  it  ever  start  from  this 
position  at  any  subsequent  baking  unless  it  is  very  much  overheated." 

Setting  the  Inlay. — After  the  foil  matrix  has  been  removed,  retain- 
ing grooves  should  be  cut  at  opposite  points  upon  the  under  side  of  the 
inlay,  in  order  that  firm  attachment  may  be  secured  to  the  cement,  or  the 
inlay  may  be  embedded,  f\ice  downward,  in  a  piece  of  warm  base-plate  wax 
and  hydrofluoric  acid  applied  to  the  back,  and  allowed  to  remain  for  about 
five  minutes.  On  carefully  washing  the  inlay  with  water  it  will  be  found 
that  the  acid  has  attacked  the  surface  of  the  porcelain,  removing  the  gloss, 
roughening  the  surface,  and  giving  it  the  appearance  of  ground  glass.  To 
this  surface  the  cement  will  adhere  with  great  tenacity,  preventing  the 
inlay  from  being  dislodged. 

The  edges  of  the  inlay  will  usually  present  a  slightly  thin,  jagged  ap- 
pearance, as  the  result  of  an  overflow  of  the  porcelain  during  the  pro- 


358  OPERATIVE    DENTISTRY. 

cess  of  firing  ;  this  should  be  carefully  smoothed  off  with  cuttle-fish  disks 
or  Arkansas  stones. 

The  inlay  is  then  secured  in  place  by  setting  it  in  zinc  oxyphosphate 
cement.  Any  ordinary  cement  having  a  finely  ground  powder,  like  the 
Justi  or  Harvard,  will  answer  the  purpose,  but  these  are  improved  by 
grinding  in  a  mortar  until  the  powder  is  impalpable. 

Coarse  powders  do  not  give  good  results,  as  the  particles  prevent  a  close 
approximation  of  the  inlay  with  the  walls  of  the  cavity,  thus  spoiling  an 
otherwise  good  fit. 

An  inlay  which  fits  perfectly,  and  which  matches  the  color  of  the  tooth, 
forms  a  joint  which  is  almost  imperceptible  to  the  unaided  vision. 

The  cement  should  be  mixed  to  the  consistency  of  cream  and  spread 
evenly  over  the  floor  and  the  walls  of  the  cavity.  The  inlay  is  then  placed 
in  position  by  means  of  the  spatula,  which  should  have  a  tiny  bit  of  cement 
on  its  surface  to  cause  the  inlay  to  adhere  to  it,  and  then  pressed  home. 
Pressure  should  be  maintained  until  the  surplus  cement  has  had  time  to 
escape  around  the  margins  of  the  inlay. 

In  approximal  cavities,  after  the  inlay  has  been  inserted,  a  wooden 
wedge  may  be  placed  between  the  approximating  teeth  to  support  the  inlay 
during  the  setting  of  the  cement,  or  cotton  and  sandarach  varnish  may  be 
used  for  the  same  purpose  and  allowed  to  remain  for  twenty-four  hours. 
The  wedge  may  then  be  removed,  and  any  projection  of  the  inlay  beyond 
the  surface  of  the  tooth  dressed  off  with  Arkansas  stones  or  cuttle-fish 
disks.  Inlays  made  from  the  porcelain  furnished  by  Dr.  Jenkins,  Ash  & 
Son,  or  the  Consolidated  Dental  Manufacturing  Company,  will  take  a 
polish  after  being  ground  equal  to  Ash  &  Son's  artificial  teeth. 

A  zinc  oxyphosphate  cement  has  recently  been  placed  upon  the  market 
by  the  Consolidated  Dental  Manufacturing  Company  which  has  been  pre- 
pared with  especial  reference  to  setting  inlays,  and  is  known  as  ''inlay 
cement."  Each  box  contains  a  bottle  of  liquid  and  four  bottles  of  powder, 
representing  the  four  basal  colors  used  in  the  making  of  the  inlays.  It  is 
therefore  possible  with  a  little  care  to  match  the  color  of  the  inlay.  The 
powders  are  very  fine,  and  form,  when  mixed  with  the  liquid,  a  very 
-smooth  and  fine-giained  mass  which  does  not  set  too  i^apidly  and  makes  a 
very  hard  and  resistant  cement. 

The  cement  forming  the  joint  of  the  inlay  should  be  protected  from 
moisture  for  a  few  hours  by  coating  it  with  sandarach  varnish,  melted 
parafQn,  or  chloro-percha. 

In  finishing  the  inlay  the  stones  and  disks  should  be  run  in  a  direction 
from  the  edge  to  the  centre,  and  never  in  the  reverse  direction,  as  there  is 
danger  of  chipping  the  edges  of  the  inlay  if  they  are  run  in  a  direction 
from  the  centre  to  the  edge.  The  final  polishing  may  be  completed  with 
pumice  and  chalk. 


CHAPTER    XXIL 

DENUDATION  OH   EROSION   OF   THE  TEETH,  AND   ATTRITION   OR   ABRASION. 

Definition. — Denudation  (Latin,  denudare, — de  and  nudare,  nudatum, — 
to  lay  bare),  the  condition  of  a  part  deprived  of  its  natural  coverings, 
whether  by  wounds,  gangrene,  or  abscess.  It  is  particularly  applied  to  the 
bones  when  deprived  of  their  iDcriosteum,  and  to  the  teeth  when  they  lose 
their  enamel  or  cement  substance,  or  when  the  gums  recede  from  them 
and  their  alveoli  are  destroyed. 

Erosion  (Latin,  erodere,  erosum,  —  e  and  rodere^  —  to  eat  away),  the 
action  of  a  corrosive  substance,  or  the  gradual  destruction  of  a  part  by  a 
substance  of  that  kind.  The  term  is  often  employed  in  the  same  sense  as 
ulceration.  It  is  a  molecular  disintegration  of  tissue  caused  by  the  action 
of  some  corroding  agent. 

Various  terms  have  been  applied  to  this  disease,  such  as  denudation, 
erosion,  surface  wear,  abrasion,  and  atrophy. 

Denudation  or  erosion  of  the  teeth  is  a  disease  which  attacks  these 
organs,  beginning  with  the  enamel  and  gradually  involving  the  subjacent 
dentin  without  any  of  the  appearances  or  characteristics  of  dental  caries. 
It  consists  of  a  gradual  wasting  away  of  the  enamel  and  dentin,  generally 
upon  the  labial  and  buccal  surfaces,  most  often  beginning  with  the  incisors, 
though  it  may  attack  the  other  teeth  first,  and  may  involve  all  of  the  teeth 
to  the  second  molars.  It  usually  begins  at  the  gum,  forming  depressed 
plains,  cavities,  or  grooves,  which  follow  the  curves  of  the  gum  lines. 
They  are  as  evenly  and  smoothly  cut  as  though  made  with  a  file  or  disk, 
are  highly  polished,  perfectly  hard,  and  many  times  absolutely  free  from 
discoloration. 

The  surface  of  the  groove  is  generally  quite  sensitive,  sometimes  ex- 
quisitely so,  causing  the  patient  much  uneasiness  and  pain.  Occasionally 
the  process  begins  at  numerous  irregular  points  on  the  labial  surface, 
which  extend,  and  after  a  time  coalesce,  involving  the  loss  of  the  entire 
enamel  wall  of  this  surface.  The  disease  progresses  in  rare  cases  as  far 
as  the  pulp,  laying  that  organ  bare,  while  in  the  majority  nature  pro- 
vides against  it  by  filling  up  the  pulp-chamber  with  secondary  dentin  and 
thus  protecting  it  from  exposure. 

In  other  cases,  after  progressing  to  a  greater  or  less  extent,  it  seems  to 
become  self- arresting. 

The  rapidity  with  which  the  disease  progresses  is  also  variable.  In 
some  cases  the  loss  of  substance  will  be  so  slow  as  to  require  ten,  fifteen, 
or  twenty  years  to  reach  the  pulp-chamber,  in  others  only  a  little  more 
than  as  many  months.  The  superior  teeth  are  much  more  liable  to  be 
attacked  than  the  inferior,  though  cases  are  quite  common  in  which  both 
are  affected,  but  the  writer  has  never  seen  the  lower  teeth  destroyed  to  the 

359 


360  .OPERATIVE    DENTISTRY. 

same  extent  as  the  upper.     The  bicuspids  are  most  often  the  seat  of  the 
disease  when  located  in  the  lower  jaw. 

Causes.— Upon  the  question  of  the  causation  or  etiology  of  the  dis- 
ease there  is  a  great  variety  of  opinions.  Up  to  the  present  time  no  definite 
conclusion  has  been  reached  by  investigators  as  to  the  real  factors  of  its 
etiology,  and  our  knowledge  of  the  subject  is  very  unsatisfactory  indeed. 

John  Hunter  was  the  first  writer  to  notice  and  describe  this  disease. 
He  named  the  disease  '^ decay  by  denudation,"  and  thought  the  disease 
was  inherent  in  the  tooth  itself,  and  stated  that  he  had  seen  cases  where  it 
appeared  as  if  the  outer  layer  of  dentin  had  been  destroyed  first,  and  that 
the  enamel  afterwards  broke  through  for  want  of  support. 

This  theory  is  evidently  erroneous,  for  no  such  phenomenon  occurs  in 
this  disease.  He  has  doubtless  confounded  it  with  that  form  of  caries  in 
which  the  enamel  becomes  partially  decalcified  in  spots  and  permits  the 
pathologic  condition  to  extend  to  the  subjacent  dentin,  when  after  a  time 
they  break  away  together,  leaving  a  shallow  cavity  more  or  less  irregular 
in  form,  but  lacking  that  smooth,  polished  condition  which  always  attends 
a  case  of  true  denudation  or  erosion. 

Bell  dissented  from  the  views  of  Hunter,  but  expressed  himself  at  a  loss 
to  explain  the  cause  of  the  disease.  He  suggested,  however,  that  the 
cause  might  be  one  of  faulty  develoj)ment  of  certain  concentric  portions 
of  enamel,  which  would  render  such  portions  more  liable  to  mechanical 
abrasion  or  other  injury  than  the  rest. 

If  such  were  the  true  explanation  we  should  expect  to  see  the  grooves 
extending  completely  around  the  necks  of  the  teeth,  but  this  condition 
never  occurs,  and  yet  certain  portions  of  enamel  may,  as  he  states,  be 
faulty  in  their  development,  but  not  necessarily,  however,  extending  com- 
pletely around  the  tooth,  and  thus  predispose  such  teeth  to  the  action  of 
solvent  agents,  as  is  believed  to  be  the  case  in  dental  caries. 

Fox  in  writing  upon  the  subject  frankly  admitted  that  he  was  unable  to 
assign  a  cause  for  the  disease,  but  thought  that  it  was  dependent  upon  some 
solvent  property  of  the  saliva.  If  the  saliva  contains  the  solvent  which 
is  responsible  for  this  disease,  we  would  expect  to  find  all  the  surfaces  of 
the  teeth  equally  affected,  for  they  are  always  more  or  less  in  contact  with 
it.  The  inferior  teeth  are  completely  bathed  in  the  saliva,  so  that  if  this 
suggestion  was  correct  the  lower  teeth  would  be  most  often  affected,  while 
clinical  experience  teaches  the  very  opposite  to  this. 

Wedl  describes  the  disease  and  classes  it  among  the  atrophies,  but 
makes  no  attempt  to  account  for  its  peculiar  manifestations.  He  calls  at- 
tention to  the  fact,  however,  that  sometimes  the  mucous  membrane  of  the 
cheeks  and  lips  is  raised  into  a  fold  opposite  the  dental  arches,  and  sug- 
gests that  it  may  be  well  to  consider,  in  future  cases,  whether  any  relation 
exists  between  the  defects  upon  the  necks  of  the  teeth  and  these  folds  or 
ridges. 

These  folds  or  ridges  the  writer  has  noticed  many  times,  but  they  are  by 
no  means  a  constant  accompaniment  of  the  disease,  and  when  such  instances 
have  occurred  he  has  been  inclined  to  consider  it  a  result  rather  than  a 
cause  of  the  disease. 


DENUDATION    OR    EROSION    OF    THE    TEETH.  361 

Salter  calls  the  affection  '^  surface  wear,"  and  ascribes  it  to  friction  of 
the  lips,  cheeks,  and  tooth-brush. 

The  surfaces  of  the  teeth  attacked  are  those  usually  reached  by  the 
tooth-brush,  and  by  many  the  disease  is  thought  to  be  one  of  mechanical 
origin  entirely  ;  but  this  cannot  be  the  case,  for  often  the  grooves  or  cavi- 
ties will  reach  around  the  teeth  mesially  and  distally  to  points  impossible 
to  be  reached  by  the  tooth-brush  or  by  folds  of  the  mucous  membrane  of 
the  lips  or  cheeks. 

The  break  in  the  tissue  is  also,  in  some  cases,  so  decidedly  undercut  as 
to  prove  conclusively  that  such  a  condition  could  not  have  been  caused  by 
the  friction  of  the  tooth-brush.  Tomes  also  observed  a  case  of  the  disease 
where  the  patient  rarely  or  never  used  the  tooth-brush,  and  Mr.  Harrison 
reported  a  similar  case  at  the  meeting  of  the  Odontological  Society  of  Great 
Britain  in  May,  1870.  But  the  most  conclusive  argument  against  the  me- 
chanical origin  of  the  disease  was  furnished  by  Dr.  Murie  in  a  paper  read 
before  the  same  society  at  its  meeting  held  in  June,  1870,  in  wliich  he 
related  the  fact  of  having  found  a  sea  lion  (the  Otaria  jubata)  whose  teeth 
showed  the  results  of  this  disease  to  a  very  considerable  extent.  The  posi- 
tions most  notably  affected  were  the  sides  of  the  teeth  where  friction 
would  be  reduced  to  the  minimum  ;  the  tusks  or  great  cuspids  were  most 
conspicuously  affected  by  the  disease. 

Tomes  thinks  this  condition,  ^'at  least  in  so  marked  a  degree,  is  not 
common  among  seals,  but  has  seen  an  approach  to  it  in  the  teeth  of  several 
specimens  of  different  species, ' '  and  he  further  says  that  in  the  museum  of 
the  Eoyal  College  of  Surgeons  may  be  seen  the  skeleton  of  a  seal  in  which 
this  condition  of  the  teeth  is  well  exemplified,  some  of  the  teeth  being 
deeply  grooved  in  positions  not  exposed  to  friction. 

Coleman  *  is  inclined  to  the  opinion  that  mechanical  attrition  is  among 
the  possible  causes  of  the  affection.  In  discussing  the  question  of  the 
presence  of  the  disease  in  seals,  he  points  out  the  fact  that  some  seals  are 
known  to  be  in  the  habit  of  taking  stones  in  their  mouths,  and  very  prob- 
ably sand  also  ;  while  hard  fish-scales  are  frequently  in  their  mouths. 
Their  long  and  flexible  tongues  are  also  capable  of  being  swept  over  the 
surfaces  of  these  eroded  teeth.  It  is  not  difficult,  therefore,  to  suppose 
that  by  these  means  the  surfaces  of  the  teeth  may  be  worn  away.  Although 
there  is  some  uncertainty  still  resting  upon  the  subject,  and  it  is  diffi- 
cult to  account  for,  still  he  thinks  from  the  foregoing  that  the  question  of 
mechanical  attrition  cannot  be  fairly  ruled  out  as  not  being  among  the 
possible  causative  factors  in  these  animals. 

Bland  Sutton  thinks  there  must  be  some  association  between  erosion  of 
the  teeth  and  defective  development.  In  a  paper  upon  comparative  dental 
pathology,  t  after  referring  to  the  condition  of  erosion  in  seals,  he  calls 
attention  to  the  reduced  dentition  of  the  elephant  seal  (the  Macrorhinus 
coninus)  whose  peg-shaped  molars  present  a  groove  around  the  entire  cir- 
cumference, which  is  perhaps  caused  by  erosion,  and  also  to  a  skull  of  the 

*  Transactions  International  Medical  Congress,  1881. 

t  Transactions  Odontological  Society  of  Great  Britain,  January,  188-i-April,  1885. 


362  OPERATIVE    DENTISTRY. 

Otaria  jubata  in  the  possession  of  Mr.  Bartlett,  in  which  the  skull  and  the 
jaws  are  affected  with  a  peculiar  porous,  soft  hyperostosis,  similar  to  that 
seen  in  the  skulls  of  rachitic  animals  at  about  the  period  of  puberty.  He 
also  refers  to  having  found  in  a  raccoon-like  dog  evident  characteristics  of 
moUities  ossiiim,  and  in  which  the  teeth  had  undergone  erosion.  He  there- 
fore comes  to  the  conclusion  that,  from  these  instances  of  erosion,  associated 
with  constitutional  bone  disease,  and  with  comparatively  functionless,  im- 
perfectly developed  teeth,  there  must  be  some  connection  between  erosion 
and  defective  development. 

He  says  further,  in  reference  to  the  process  of  absorption  which  some- 
times attacks  the  functionless  tusks  of  the  female  Indian  elephant, 
"Pathologists  have  long  been  aware  that  morbid  changes  are  more  prone 
to  attack  undeveloped  functionless  or  imperfectly  acting  organs ',  hence  I 
imagine  that  the  tusks  of  female  elephants  are  more  prone  to  inflammation 
than  the  fully  developed  representatives  in  the  male." 

Magitot  regarded  the  disease  as  a  result  of  caries  which  has  been  spon- 
taneously cvired  or  arrested  by  the  obliteration  (filling  up)  of  the  dental 
tubuli. 

It  is  difficult  to  understand  how  this  author,  for  whom  the  writer  has 
the  greatest  respect,  can  arrive  at  such  a  conclusion  from  the  phenomena 
presented  by  the  disease.  If,  as  he  suggests,  it  is  caries  in  the  incipient 
stage,  arrested  by  or  cured  by  the  obliteration  of  the  tubuli  from  a  deposi- 
tion of  calcareous  matter,  why  is  it  that  in  almost  every  case  the  teeth  thus 
affected  are  sensitive,  sometimes  exquisitely  so,  to  the  touch  of  an  instru- 
ment, changes  of  temperature,  acid  condiments,  and  confections  ?  Calcified 
nerve-tissue  has  no  sensation  (assuming  that  nerve-fibrils  penetrate  the 
tubuli  of  the  dentin)  ;  hence  his  theory  in  this  respect  must  be  erroneous. 
These  cases  are  also  usually  progressive,  many  times  extending  over  a 
series  of  years,  and  perceptible  changes  can  be  noted  from  time  to  time. 

Tomes  calls  attention  to  another  form  of  the  affection  in  which  the  loss 
of  substance  is  not  merely  confined  to  isolated  spots  or  surfaces,  but  in  which 
the  whole  exposed  portion  of  the  tooth  is  attacked.  "As  the  morbid 
action  goes  on  the  enamel  is  slowly  removed  from  the  crown,  so  that  the 
teeth  become  shorter  and  thinner  and  assume  a  peculiar  yellowish,  trans- 
lucent appearance,  the  position  of  the  pulp  being  strongly  marked  by  the 
difference  in  color.  In  the  only  case  which  has  come  under  my  own  obser- 
vation, the  wasting  of  the  teeth  was  established  beyond  all  doubt  by  taking 
models  from  time  to  time.  The  patient,  an  anaemic  girl,  was  reduced  to  a 
state  of  great  prostration  by  acute  dyspepsia,  and  was  for  a  considerable 
time  confined  to  her  bed  ;  she  was,  however,  so  hysterical  that  it  was  ex- 
ceedingly difficult  to  rightly  estimate  her  condition.  At  one  time  thei^e 
was  great  tenderness  of  her  teeth  and  general  periostitis  in  the  front  of  the 
mouth,  which,  judging  by  color  alone,  appears  to  have  resulted  in  the 
death  of  one  of  the  upper  central  incisors.  The  use  of  alkaline  applications 
seemed  to  have  no  effect  whatever,  but  the  patient's  condition  has  now 
greatly  improved,  and  the  disease  appears  to  be  no  longer  progressing.  It 
is  remarkable  that  during  her  prolonged  illness,  while  the  teeth  were  being 
rax)idly  eroded,  no  caries  occurred  in  the  mouth." 


DENUDATION    OR    EROSION    OF    THE    TEETH.  363 

The  writer  has  reported  a  case*  of  a  somewhat  similar  character  occur- 
ring in  a  gentleman  of  leisure  about  forty-five  years  of  age,  in  which  the 
six  anterior  teeth  and  the  right  first  bicuspid  of  the  upper  jaw  are  quite 
extensively  denuded,  the  enamel  being  entirely  removed  from  all  of  the 
teeth  named  upon  their  anterior  surfaces,  with  a  considerable  portion  of  the 
dentin,  leaving  an  inclined  plane  pointing  backward,  and  extending  from 
the  margin  of  the  gums  to  the  ends  of  the  teeth,  shortening  the  anterior 
teeth  to  the  extent  of  about  a  sixteenth  of  an  inch. 

The  denuded  surfaces  were  not  all  grooved  in  one  direction  ;  the  central 
incisors  and  the  left  lateral  were  grooved  horizontally  like  the  others,  but 
were  also  grooved  longitudinally  at  the  cutting  edges. 

The  first  and  second  bicuspids  of  the  lower  jaw  on  the  right  side  were 
also  affected,  but  not  to  the  same  extent  as  those  of  the  upper  jaw.  Fifteen 
years  before.  Dr.  Allport,  of  Chicago,  filled  with  gold  the  six  anterior  teeth 
upon  their  cutting  edges,  for  the  front  teeth  originally  occluded  squarely, 
and  by  mechanical  abrasion  cup-shaped  cavities  had  been  worn  into  the 
dentin,  making  it  necessary  to  fill  them.  The  centrals  were  also  slightly 
decayed  at  the  margin  of  the  gums,  and  small  fillings  were  also  inserted 
there. 

Six  years  afterwards  it  was  first  observed  that  the  disease  had  attacked 
the  teeth  ;  two  years  later  it  had  progressed  so  far  as  to  make  the  edges  of 
the  fillings  stand  out  above  the  surrounding  tissue  on  the  labial  surfaces. 
These  edges  were  rounded  off  and  the  case  dismissed  for  the  time  being. 
Shortly  afterwards  the  gentleman  went  to  Europe  and  remained  there  four 
years.  On  his  return  not  a  vestige  of  the  fillings  was  left,  nor  even  a  de- 
pression to  indicate  where  they  had  been,  the  surface  being  as  smooth  and 
regular  as  though  cut  and  polished  with  file  or  disk. 

There  had  also  been  a  i^ercei^tible  loss  of  structure  during  the  past  three 
years,  but  the  destruction  had  been  much  less  rapid  than  previously. 

Numerous  other  cases  might  be  mentioned  to  substantiate  this  posi- 
tion, as  well  as  the  fact  that  it  does  not  originate  in  incipient  caries.  Cases 
have  occurred  in  their  incipiency  and  progressed  stage  by  stage  under  our 
eyes,  and  at  no  time  have  they  shown  any  signs  of  decay. 

In  the  case  just  mentioned  two  of  the  teeth  were  slightly  decayed  at  the 
gum  line,  but  none  of  the  others  were  at  any  time  affected  in  this  way. 

Underwood  f  reported  a  case  ' '  occurring  in  a  lady  of  middle  age,  who 
became  the  subject  of  erosion  after  a  severe  attack  of  rheumatic  gout  ac- 
companied by  great  depression  and  mental  shock  of  a  severe  character.  She 
had  never  worn  an  artificial  denture.  All  of  the  surfaces  of  the  teeth 
were  impartially  attacked,  so  that  one  bicuspid  was  reduced  to  a  cube  of 
dentin  minus  the-eaamel  on  all  sides,  while  others  presented  polished 
grooves  traversing  their  surfaces  in  all  directions,  contrary  to  the  usual  form 
in  which  the  loss  of  substance  is  limited  to  the  crevices  of  the  teeth.  True 
caries  was  also  present  in  the  mouth  ;  the  reaction  of  the  saliva  was 
strongly  acid  even  just  after  a  meal.     Two  sisters  and  a  niece  of  the  patient 

*  Transactions  of  the  American  Medical  Association,  1884. 
t  Aids  to  Dental  Surgery. 


364  OPERATIVE    DENTISTRY. 

were  free  from  the  affection.  One  of  the  sisters,  however,  had  at  a  later 
period  shown  signs  of  the  disease." 

The  late  Dr.  Eleazer  Parmley,  of  ^STew  York,  reported  some  years  ago 
a  case  in  which  erosion  attacked  natural  teeth  that  had  been  set  upon 
an  artificial  piece  in  precisely  the  same  manner  as  in  teeth  having  natural 
attachments  to  the  alveolus. 

J.  Tomes  and  Harris  are  both  inclined  to  think  the  disease  is  one  of 
chemical  origin.  Tomes  suggests  that  it  is  caused  by  the  fluid  secreted  by 
the  mucous  membrane  covering  the  parts  affected,  undergoing  fermenta- 
tion, or  affording  a  nidus  for  fermentation,  and  thus  may  provide  an  acid 
solvent. 

Harris  adopts  the  opinion  that  the  loss  of  substance  which  characterizes 
the  affection  is  produced  by  the  action  of  acidulated  buccal  mucus.  In 
every  other  part  of  the  mouth  this  fluid  is  mixed  with  saliva,  and  the  acid 
it  contains  is  so  diluted  as  to  prevent  it  from  acting  on  other  portions  of 
the  teeth. 

The  view  held  by  these  authors  is  the  one  most  generally  accepted, 
perhaps  because  no  better  theory  has  been  advanced.  This  theory,  how- 
ever, does  not  account  for  all  the  j)eculiarities  of  the  disease.  To  illus- 
trate :  certain  teeth  are  affected  in  individual  cases  to  the  exclusion  of 
others.  The  writer  has  had  several  cases  where  the  disease  attacked  the 
superior  incisors  and  bicuspids,  while  the  canines  were  entirely  free,  and 
vice  versa,  and  one  marked  case  of  the  disease  in  the  lower  bicuspids  on 
both  sides,  while  all  the  other  teeth  of  the  mouth  escaped  entirely. 

The  writer  has  frequently  tested  these  cases  with  litmus-paper  to  ascer- 
tain the  condition  of  the  mucous  secretions  of  the  lips  and  cheeks,  but  has 
never  found  any  very  marked  acid  reaction  ;  in  fact,  has  often  foand  greater 
reaction  in  mouths  where  the  teeth  were  entirely  free  from  the  disease. 

For  several  years  two  brothers  who  were  manufacturers  of  sulphuric 
acid  were  under  the  professional  care  of  the  writer.  One  of  them  had 
charge  of  the  stills,  and  the  other  of  the  chemic  laboratory.  The  former 
was  for  hours  at  a  time  in  a  room  the  atmosphere  of  which  would  be 
highly  charged  with  the  fumes  of  the  sulphuric  acid,  making  it  necessary 
to  wear  a  wet  sponge  over  the  nose  and  mouth  to  protect  the  air-passages 
from  its  irritating  effects.  The  latter  was  also  subjected  to  the  fumes  of 
the  acid,  but  to  a  much  less  extent  than  his  brother.  Both  of  these  gentle- 
men suffered  very  greatly  from  dental  caries  during  the  years  that  they 
occupied  these  positions,  but  when  they  gave  up  this  part  of  the  work 
there  was  a  marked  decrease  in  the  amount  and  progress  of  the  caries. 

In  the  brother  who  spent  so  much  time  in  the  distillery  room  a  con- 
dition similar  to  erosion  occurred  upon  the  labial  surfaces  of  the  ten 
anterior  teeth  of  both  jaws,  but  upon  leaving  this  work  to  be  done  by 
others  the  progress  of  the  disease  was  permanently  arrested,  as  shown  by 
the  fact  that  there  has  been  no  further  progress  for  the  past  ten  years. 

In  an  article  translated  from  the  German  by  C.  E.  Koch,  and  published 
in  the  Missouri  Dental  Journal,  August,  1872,  the  author  advances  the 
theory  that  the  disease  is  one  having  a  close  analogy  to  the  process  of 
resorption,  attacking  the  roots  of  the  deciduous  teeth  prior  to  their  being 


DENUDATION    OR    EROSION    OF    THE    TEETH. 


365 


replaced  by  the  permanent  organs.  He  claims  that  '•  the  gum  may  secrete 
a  fluid  endowed  with  functions  similar  to  those  possessed  by  the  absorbent 
organ  found  at  the  roots  of  the  deciduous  teeth,  and  by  this  means  the 
tissues  are  removed,  leaving  the  surfaces,  as  iu  the  case  of  the  roots  of  the 
teeth  just  mentioned,  smooth  and  polished  ;"  but  qualified  his  statement  by 
saying  that  he  '^  feels  inclined  to  assume  at  least  a  predisposition  of  the  tooth 
concerned,  for  the  reason  that  in  all  cases  only  certain  teeth  are  attacked 
by  it."  He  bases  his  argument,  however,  upon  what  he  assumes  to  be  a 
fact,— viz.,  "that  denudation  always  appears  upon  the  neck  of  the  tooth." 
He  has  evidently  overlooked  the  fact  that  cases  of  the  disease  occur,  as  we 
have  already  stated,  upon  the  labial  and  buccal  surfaces,  remote  from  the 
margin  of  the  gums,  at  points  not  likely  to  be  reached  by  the  eroding  fluid 
in  sufficient  strength  to  account  for  the  rapid  progress  of  the  disease  in 
some  of  these  cases. 


Tig.  479. 


Fig.  480. 


^«JUUi  iU 


Teeth  where  the  graiie-oiire  has  been  taken. 
(After  Dr.  Darby.) 


Case  attributed  to  the  use  of  acid  phosphate. 
(After  Dr.  Darby.) 


Fig.  479  represents  a  case  of  this  character  reported  by  Dr.  E.  T. 
Darby,  in  which  the  affection  developed  while  the  patient  was  taking  the 
grape-cure,  and  another  case,  illustrated  in  Fig.  480,  in  which  the  loss  of 
tissue  is  at  the  cervices  of  the  teeth,  was  ascribed  to  the  use  of  acid  phos- 
phate. 

Taft  is  of  the  opinion  that  an  acidulated  buccal  mucus  is  the  essential 
factor  in  producing  erosion,  and  thinks  that  constitutional  treatment  may 
have  a  controlling  effect  ujDon  the  disease. 

Charles  E.  Tomes  is  inclined  to  the  belief  that  mechanic  abrasion  does 
not  fully  account  for  the  disease,  and  that  some  other  factor  must  play  an 
important  part  in  the  process. 

Truman  has  long  maintained  that  the  disease  was  caused  by  an  acid  fer- 
mentation taking  place  in  the  mouth,  more  especially  at  night  or  when 
the  mouth  was  in  repose,  and  in  corroboration  of  this  theory  proved  by 
tests  with  litmus  that  the  secretions  of  the  mouth  almost  iuvariablj'  gave 
an  acid  reaction  upon  rising  in  the  morning  and  after  a  fast  of  several 
hours'  duration. 

Kirk  believes  erosion  to  be  produced  by  the  solvent  action  of  the  product 
of  the  buccal  mucous  glands. 

Garretson  was  of  the  opinion  that  the  true  exj)lauatiou  of  the  cause 
of  this  disease  was  that  enunciated  in  the  experiments  of  Mr.  Kincely 
Bridgman,  the  author  of  the  electrochemical  theory  of  decay,  and  he 


366 


OPERATIVE    DENTISTRY. 


says,  ''My  present  convictions  have  led  me  to  believe  that  in  this  direc- 
tion will  be  found  to  lie  not  only  the  cause  of  the  disease  Imt  the  pro- 
phylaxis." He  furtlier  says,  "It  would  seem,  however,  that  back  of  the 
immediately  acting  cause  must  be  a  predisposition  ;  here  it  would  seem  to 
be  the  result  of  impressions  made  on  the  enamel  at  the  period  of  its  forma- 
tion, and  which  deficiency  the  nutritive  functions  have  failed  to  correct. 
It  might,  indeed,  very  well  be  that  such  enamel  is  entirely  deficient  in 
vital  resistance,  and  thus  subject  to  be  acted  upon  as  any  inorganic  struc- 
ture, being  by  electrolytic  action  simply  dissolved." 

Black  *  has  produced  a  condition  by  artificial  means  out  of  the  mouth 
which  closely  resembles  erosion.  In  one  experiment  which  he  records 
two  freshly  extracted  and  sound  bicuspid  teeth  were  placed  with  their 
proximal  surfaces  together  and  their  roots  enveloped  in  gutta-percha, 
so  that  their  crowns  only  were  exposed.  These  were  then  placed  in  a 
glass  jar  containing  a  dilute  solution  of  hydrochloric  acid  (one  to  four 
hundred),  and  by  means  of  a  revolving  glass  paddle-wheel,  run  by  a 
clock-like  mechanism  and  making  forty  revolutions  per  minute,  a  current 
was  made  to  impinge  upon  their  outer  surfaces,  the  current  striking  one 
with  greater  force  than  the  other.  The  result  at  the  end  of  five  days 
was  the  disappearance  of  the  cusps  and  the  formation  of  a  groove  be- 
tween the  teeth.  This  groove  was  most  marked  upon  the  tooth  which 
received  the  greatest  force  of  the  current.  These  exi3eriments  were  re- 
peated a  number  of  times  with  slightly  varying  results.  Stronger  solu- 
tions i^roduced  general  soften- 
ing, while  solutions  of  the 
strength  of  one  of  acid  to  fifteen 
hundred  of  water,  after  a  three 
months'  trial,  gave  no  appre- 
ciable results.  Dr.  Black,  how- 
ever, does  not  look  upon  these 
experiments  as  proving  any- 
thing as  to  the  etiology  of  the 
disease.  He  says,  however, 
' '  the  theory  that  it  is  caused  by 
acid  mucus  is  suj^ported  by 
several  who  have  written  on  the 
subject,  and  our  present  knowl- 
edge affords  no  alternative  but 
the  acceptance  of  the  general 
idea  that  it  is  the  action  of  an 
acid  under  some  peculiar  modi- 
fying influence  as  yet  unknown 
to  us." 
Darby  maintains  that  many  cases  of  erosion  are  associated  with  the 
gouty  diathesis,  and  believes  that  this  constitutional  condition  is  an  im- 
portant factor  in  the  causation  of  the  disease.     The  accompanying  illus- 


FiG.  481. 


Case  where  there  was  gouty  relation.    (After  Dr.  Darby.) 


Fig.  482. 


Case  where  there  v.-ag  gouty  relation.    (After  Dr.  Darby.) 


American  System  of  Dental  Surgery,  vol.  i.  p.  1004. 


DENUDATION    OR    EROSION    OF    THE    TEETH.  367 

trations  (Figs.  481  and  482)  repi-esent  cases  that  were  associated  willi  tlie 
gouty  diathesis. 

The  writer  has  frequently  noticed  that  the  teeth  most  often  attacked  by 
denudation  or  erosion  are  those  that  are  generally  classed  as  medium  or  soft 
teeth,  or  are  low  in  vital  resistance,  the  patient  often  inheriting  a  peculiar 
cachexia,  the  scrofulous  or  syphilitic,  which  has  had  a  depressing  influeuce 
upon  the  developmental  j^rocess,  thus  lowering  the  power  of  vital  resist- 
ance and  predisposing  the  teeth,  as  well  as  other  organs  of  the  body,  to 
the  ravages  of  disease. 

There  is  no  doubt  that  the  structure  of  the  teeth  is  often  affected  by 
certain  diseases.  The  marks  which  they  leave  on  particular  portions  of 
the  tissue  tell  at  what  time  the  injuiy  was  wrought  and  indicate  the  cause 
of  the  disturbance.  Syphilis,  small-pox,  whooping-cough,  scarlet  fever, 
and  the  jDustular  diseases  leave  characteristic  marks  by  which  it  can  be 
told  at  what  portion  of  the  developmental  i)eriod  their  influence  was  felt. 

A  peculiar  form  of  the  disease  is  that  in  whicli  the  loss  of  the  substance 
of  the  teeth  is  confined  to  the  morsal  edges  of  the  anterior  teeth. 

Harris  *  relates  a  case  of  this  character  in  which,  during  the  course  of 
two  years,  a  sex)aration  was  formed  between  the  ends  of  the  incisors  of 
three-eighths  of  an  inch. 

Bell  has  also  described  a  similar  case  affecting  mainly  the  morsal  edges 
of  the  incisors  and  cuspids,  which  could  not  be  brought  into  contact  with 
each  other.  The  opening  formed  between  the  ends  of  the  teeth  was  ellij)- 
tical  in  shape.  This  form  of  the  disease  cannot  by  any  possibility  be 
attributed  to  mechanical  abrasion  or  attrition.  By  some  it  has  been 
thought  to  be  caused  by  an  acid  mucus  secreted  by  the  glandular  structures 
of  the  surface  of  the  tii^  of  the  tongue,  which  lying  in  contact  with  the 
lingual  surfaces  of  the  anterior  teeth  at  the  morsal  edges — except  during 
speech  or  mastication — would  keep  the  solvent  fluid  in  almost  constant 
contact  with  these  surfaces. 

Pathology. — -Underwood  found  in  the  examination  of  sections  of 
enamel  at  the  seat  of  erosion  that  the  tissue  was  structurally  defective, 
having  an  exaggerated  granular  appearance.  Sections  of  dentin  showed 
simply  the  abrupt  ending  of  the  fibrils  and  tubules  as  if  cut  with  a  sharp 
instrument.  An  interesting  fact  was  also  discovered, — viz.,  that  stained 
as  carefully  as  possible  the  substance  adjacent  to  the  eroded  surface  does 
not  take  the  stain,  a  condition  that  might  be  expected  if  really  due  to  the 
action  of  an  acid  solvent. 

Black  says,  ^'N"either  the  dentin  nor  the  enamel  immediately  adjacent 
to  the  portions  being  removed,  even  uj)  to  the  immediate  surface,  shows 
any  changes  whatever,  except  it  be  a  slight  discoloration  which  is  present 
in  only  a  portion  of  the  cases." 

The  writer  has  observed  that  when  discoloration  became  permanent 
upon  an  eroded  surface  caries  soon  attacked  this  surface.  The  disease  in 
some  cases  api^ears  to  be  self-limiting,  while  in  others  it  is  progressive. 

Treatment. — Tlie  treatment  of  denudation  or  erosion  is  very  unsatis- 

*  Dental  Surgery,  p.  264. 


368  OPERATIVE    DENTISTRY. 

factory,  for  no  remedy  has  yet  been  discovered  whicli  will  arrest  the 
progress  of  the  disease.  Certain  remedies  are  sometimes  applied  in  an  em- 
pirical sort  of  way,  with  the  view  of  checking  the  progress  of  the  disease, 
like  alkaline  mouth- washes,  antiseptic  solutions,  and  alcohol,  and  the  dis- 
continuance of  the  use  of  tooth-powders  and  stiff  tooth-brushes.  To  relieve 
the  extreme  hypersensitive  condition  of  the  dentinal  fibrillse  the  eroded 
surfaces  may  be  touched  with  zinc  chloride,  or  if  the  surface  is  not  exposed 
to  view,  it  may  be  touched  with  silver  nitrate. 

In  the  more  advanced  stages  of  the  disease  the  cavity  thus  formed  may 
be  properly  shaped  and  filled  with  gold.  This  operation  in  many  cases 
does  not  seem  to  arrest  or  even  check  the  progress  of  the  disease,  for  it  is 
the  experience  of  most  operators  that  in  from  three  to  six  years  these 
fillings  will  be  lost  by  reason  of  the  disease  progressing  until  the  sup- 
ports of  the  filling  were  dissolved  away. 

Tlie  writer  has  found  that  in  a  certain  few  cases  zinc  oxyphosphate 
cement  seemed  to  exert  a  controlling  effect  upon  the  disease,  and  in  these 
cases  the  cement  fillings  lasted  exceptionally  long.  Whether  this  was  due 
to  some  peculiar  action  of  the  cement,  to  a  chance  association  of  a  changed 
condition  in  the  oral  fluids,  or  to  a  natural  limitation  of  the  disease,  it  would 
be  very  difficult  to  decide.  One  marked  effect  of  protecting  the  eroded 
surfaces  with  zinc  oxyphosphate  was  the  abatement,  after  a  few  weeks,  of 
the  extreme  hypersensitiveness. 

ATTRITION   OR   ABRASION. 

Definition. — Attrition  (Latin,  atterere,  to  rub  against),  any  rubbing  or 
friction  which  wears  a  surface.  Applied  to  the  teeth,  it  is  the  wearing 
away  of  the  tooth  -substance,  caused  by  the  friction  of  mastication .  Abrasion 
(Latin,  abrasio  ;  ab,  priv.,  radere,  to  rub),  in  dentistry,  the  wearing  away  of 
the  enamel  and  dentin  ui)on  the  morsal  surfaces  by  mechanical  means,  or 
a  loss  of  substance  through  friction  of  a  foreign  body. 

Mechanical  attrition  of  the  teeth  is  a  common  condition  in  individuals 
past  middle  life  and  in  the  deciduous  teeth  of  children.  The  morsal  sur- 
faces of  the  bicuspids  and  molars  are  most  often  the  seat  of  this  loss  of 
substance,  but  when  the  occlusion  of  the  teeth  is  such  that  the  six  anterior 
teeth  impinge  squarely  upon  each  other,  the  morsal  edges  of  the  incisors 
and  the  cusps  of  the  cuspids  also  become  worn  away,  forming  broad  surfaces, 
which  has  given  rise  to  the  notion  among  some  of  the  less  intelligent  laity 
that  some  people  "have  double  teeth  all  around."  As  the  process  of  attri- 
tion goes  on  the  teeth  become  shorter  and  shorter  until  in  some  cases  they 
are  actually  worn  down  to  the  gums.  Some  animals,  notably  the  rodents, 
have  teeth  which  grow  continually,  so  that  the  wear  which  takes  place 
from  the  severe  use  to  which  they  are  subjected  is  counterbalanced  by  their 
continuous  growth.  Not  so  with  man,  for  with  his  teeth  when  once  fully 
developed  there  is  no  compensation  for  wear  or  injury.  Unlike  other 
organs  and  tissues  of  his  body,  they  are  incapable  of  repairing  losses  which 
may  be  sustained  by  disease,  injury,  or  wear.  A  certain  amount  of  wear 
always  takes  place  upon  the  morsal  surfaces  and  edges  of  the  teeth  from 
childhood  to  old  age  ;  this  would  be  termed  normal  attrition. 


DENUDATION    OR    EROSION    OF    THE    TEETH.  369 

On  the  other  hand,  the  wear  which  takes  place  in  some  cases  is  entirely- 
abnormal. 

Causes.— The  amount  of  attrition  which  may  take  place  in  any  indi- 
vidual case  will  depend  very  largely  upon  the  character  of  the  food,  the 
density  of  the  tooth-structure,  the  form  of  the  occlusion,  and  the  habits. 

It  may  attack  the  morsal  surfaces  of  all  of  the  teeth,  or  it  may  affect 
only  one  or  two  teeth.  When  tlie  anterior  teeth  occlude  squarely  together 
all  of  the  teeth  will  be  worn  by  attrition.  When  the  occlusion  is  normal 
only  the  bicuspids  and  the  molars  will  be  affected,  but  when  the  attrition  is 
localized  it  will  be  due  to  malposition  or  irregularity  of  one  or  more  teeth, 
or  to  some  peculiar  habit,  like  holding  a  pipe  between  the  teeth  always  in 
the  same  location. 

The  character  of  the  food  plays  an  important  part  in  the  normal  wear 
or  attrition  of  the  teeth.  Foods  which  are  hard  and  require  considerable 
mastication  or  grinding  to  reduce  them  to  a  proper  state  to  enter  the 
stomach  cause  more  surface  wear  of  the  teeth  than  foods  which  are  soft. 
This  is  particularly  noticeable  in  the  museum  collection  of  skulls  of  abo- 
riginal x)eoples  whose  food  was  coarse  and  contained  much  giitty  material 
intermixed  with  it,  as  a  result  of  their  primitive  method  of  grinding  their 
cereals.  The  same  conditions  are  noticeable  in  the  negro  of  the  South, 
and  in  sailors  and  soldiers  who  have  been  in  service  for  long  terms,  and 
whose  food  has  been  of  necessity  composed  of  coarse  and  hard  materials. 

Predisposing  Causes. — It  has  been  thought  by  some  authorities  that 
the  difference  in  the  density  of  tooth-structure  was  an  imi^ortant  predis- 
posing factor  in  the  attrition  of  the  teeth.  Confidence  in  the  importance  of 
this  theory  as  a  causative  factor  in  the  wearing  away  of  the  teeth  has  been 
somewhat  severely  shaken  by  the  publication  of  the  results  of  Dr.  Black's 
experimental  research  into  the  question  of  the  differences  of  density  in 
the  teeth  of  individuals  from  youth  to  old  age.  He  found,  as  already  re- 
ferred to  in  another  part  of  this  work,  that  the  differences  were  so  slight  as 
to  be  of  no  importance  as  a  controlling  influence  in  the  predisposition  to 
caries,  and  these  conclusions  are  equally  aj^plicable  to  the  pi-edisposition 
of  the  teeth  to  be  worn  away  by  attrition. 

The  most  important  predisposing  cause  of  mechanical  attrition  is  an 
abnormal  occlusion  of  the  teeth.  When  the  teeth  of  the  opposing  jaws 
form  a  normal  occlusion,  the  cusps  of  the  bicuspids  and  molars  interlock- 
ing with  each  other,  the  buccal  cusps  of  the  superior  teeth  shutting  over 
the  buccal  cusps  of  the  inferior  teeth,  and  the  superior  incisors  and  cuspids 
shutting  over  those  of  the  lower  jaw,  the  surface  wear  or  attrition  will 
occur  in  the  bicuspids  and  molars  upon  the  sides  of  the  cusjis  which  come 
into  antagonism,  and  thus  the  grinding  and  triturating  character  of  these 
teeth  will  be  maintained  to  the  end  of  life  ;  while  the  incisive  and  tearing 
character  of  the  anterior  teeth  will  be  maintained  by  the  same  normal 
process  or  wear. 

If,  on  the  other  hand,  the  occlusion  of  the  teeth  is  such  that  the  points 
of  the  cusps  of  the  posterior  teeth  and  the  morsal  edges  of  the  incisors  and 
cuspids  only  come  in  contact,  a  sliding  motion  of  the  teeth  of  one  jaw  upon 
those  of  the  other  becomes  necessary  in  triturating  and  grinding  the  food. 

24 


870  OPERATIVE    DENTISTRY. 

In  time  the  cusps  of  the  teetli  are  completely  worn  away,  and  the  morsal 
or  incisive  edge  of  the  anterior  teeth  is  destroyed,  thus  reducing  the  mor- 
sal surfaces  to  flat  planes.  As  soon  as  the  enamel  upon  these  surfaces  is 
lost  at  any  one  point,  the  dentin  wears  away  so  much  more  rapidly  than 
the  remaining  enamel  that  cup  shaped  depressions  are  formed  in  the 
dentin,  which  grow  deeper  and  deeper  until  they  become  an  annoyance 
either  from  their  extreme  sensitivenesss  or  from  the  retention  of  food  debris. 

The  malocclusion  of  one  or  more  teeth  often  causes  a  localized  attrition, 
as,  for  instance,  when  a  lateral  incisor  or  a  bicuspid  is  so  malposed  as  to 
throw  it  out  of  the  normal  alignment  of  the  dental  arch,  thereby  causing 
it  to  interlock  with  the  ox^posing  tooth  in  such  a  manner  as  to  produce 
excessive  attrition  upon  the  labial  or  lingual  surfaces  of  these  teeth. 

Another  cause  of  abnormal  attrition  is  the  loss  of  several  teeth  upon 
one  or  both  sides  of  the  jaw,  thus  throwing  extra  work  upou  the  remain- 
ing teeth.  The  most  common  condition  of  this  character  is  where  the 
posterior  teeth  have  been  lost,  and  the  whole  labor  of  triturating  and 
grinding  the  food  is  thrown  upon  the  anterior  teeth. 

Habit  is  also  an  imjDortant  factor  in  the  attrition  of  the  teeth.  This 
is  noticed  in  certain  individuals  who  when  the  mind  is  engaged  are  con- 
stantly grinding  their  teeth  together,  or  who,  by  canying  the  jaw  forward 
or  laterally,  bring  two  teeth  together,  and  by  a  constant  rubbing  motion 
wear  away  the  prominent  points  of  these  teeth.  ■  The  habit  once  formed 
usually  remains,  and  thus  an  abnormal  attrition  of  the  teeth  involved  is 
produced. 

Pathology. — Smale  and  Colyer*  claim  that  attrition  is  always  most 
marked  in  those  individuals  who  are  of  a  gouty  diathesis. 

The  only  changes  observable  in  the  structures  of  the  dental  tissues  are 
the  abrupt  ending  of  the  dentinal  tubules  at  the  worn  surface,  the  evident 
consolidation  of  the  fibrillse  in  certain  cases,  the  deposition  of  secondary 
dentin  in  the  pulp-chamber  nearest  to  the  point  of  surface  wear,  and 
atrophic  changes  in  the  pulp  itself. 

Treatment. — In  many  of  these  cases  treatment  is  not  required.  In 
those  in  which  cavities  or  depressions  have  been  worn  in  the  surfaces  of 
the  teeth  a  retentive  shape  should  be  given  to  them  and  the  cavities  filled 
with  gold.  In  those  in  which  the  pulj)  has  been  dangerously  ax)i:>roached 
gold  crowns  may  be  inserted  and  the  normal  sej)aration  of  the  jaws  re- 
stored, porcelain  facings  or  porcelain  crowns  being  used  in  all  locations 
in  which  the  artistic  sense  would  be  offended  by  the  exhibition  of  glitter- 
ing gold  crowns. 

When  the  posterior  teeth  have  been  lost  and  the  anterior  teeth  are 
being  rajiidly  worn  down,  artificial  dentures  should  be  inserted  and  the 
"  bite"  lengthened  so  as  to  relieve  the  wear  upon  the  anterior  teeth.  "When 
the  insertion  of  artificial  dentures  will  not  be  permitted,  the  ends  of  the 
anterior  teeth  may  be  protected  by  the  insertion  of  gold  fillings  which 
cover  the  edges  of  the  enamel  and  lengthen  the  "  bite,"  as  described  in  a 
preceding  part  of  this  work. 

•^  Diseases  and  Injuries  of  the  TeetL,  \).  282. 


DENUDATION   OR   EROSION   OF   THE   TEETH.  371 

Abrasion.— By  the  use  of  the  term  abrasion  the  writer  means  that  loss 
of  tooth-substance  which  is  caused  by  the  friction  of  foreign  bodies  as  for 
instance,  artificial  dentures  made  upon  a  metal  base  or  retained  in  the 
mouth  by  metal  clasps  which  surround  certain  teeth  ;  the  undue  applica- 
tion of  the  tooth-brush  and  of  dentifrices ;  the  use  of  the  clay  pipe,  and 
of  chewing  tobacco  and  the  betel-nut. 

The  most  common  cause  of  abrasion  is  the  friction  of  metal  plates  and 
clasps.  This  condition  is  most  likely  to  occur  when  the  plate  or  the  clasp 
does  not  properly  fit,  thus  permitting  constant  motion  during  speech  and 
mastication.  These  losses  of  substance  are  always  at  those  points  upon  the 
teeth  where  the  friction  has  been  applied.  Such  abraided  surfaces  often 
become  exquisitely  sensitive  and  call  for  treatment.  When  these  abrasions 
occur  in  locations  not  readily  kept  clean  caries  is  liable  to  supervene. 

Abrasions  from  the  use  of  the  tooth-brush  and  dentifrices  are  exceedingly 
rare.  A  few  such  cases  will,  however,  present  in  the  practice  of  nearly 
every  dentist,  but  they  appear  so  seldom  that  they  are  usually  encountered 
as  a  surprise.  Individuals  who  have  this  form  of  abrasion  are  those  who 
are  so  scrupulously  neat  about  the  care  of  their  mouths  that  for  fear  they 
will  not  keep  their  teeth  clean  they  employ  the  stiflest  brushes  that  can 
be  found,  and  often  add  pulverized  pumice-stone  to  their  dentifrices  to  be 
sure  that  all  stains  and  deposits  are  prevented  from  accumulating  upon 
them.  These  abrasions  are  usu- 
ally found  upon  the  labial  and  Fig.  483. 
buccal  surfaces  of  the  teeth,  and 
might  be  readily  mistaken  for 
denudation  or  erosion  (Fig.  483). 

Abrasions  from  the  use  of  the 
clay  pipe  are  most  frequently 
seen  among  the  x)eoj)le  of  the 
lower  walks  of  life,  particularly  "" 

-,    ^  T         •  ,    -1  Case  showing  abrasion  by  tooth-brush.     (After 

among  laborers  having  out-door  Dr  s  b  Palmer ) 

occupations,  who  smoke  a  great 

deal,  and  hold  the  pipe  gripped  between  the  teeth  while  at  work.  The 
stem  of  the  pipe  is  usually  held  in  the  same  place,  and  after  a  time  the 
teeth  become  worn  at  this  x^oint  to  such  an  extent  that  they  do  not  occlude, 
and  an  ojDen  space  the  form  of  the  pipe-stem  remains  when  the  other  teeth 
are  in  contact.  The  writer  once  saw  an  elderly  Irishwoman  who  was  a 
constant  user  of  the  clay  pipe,  in  whom  the  groove  formed  between  the 
opjDOsing  teeth  at  the  angle  of  the  mouth  was  so  deep  and  large  that  she 
had  been  of  late  years  obliged  to  wind  the  stem  of  her  pipe  with  a  strip 
of  linen  to  make  it  large  enough  to  be  gri]:)ped  by  the  worn  teeth. 

Abrasion  from  chewing  tobacco  is  quite  common  among  old  sailors  and 
the  negroes  in  the  tobacco-raising  districts  of  the  South,  while  among  the 
native  low-caste  Hindoos  and  Burmese,  who  mix  lime  with  their  betel-nut 
to  form  a  pungent  •'quid,-'  abrasion  is  verj-  common.  Tobacco  and  betel- 
nut  chewers,  as  a  rule,  always  chew  the  quid  upon  the  same  side  of  the 
mouth,  and  as  a  consequence  the  abrasion  always  occurs  upon  that  side. 
The  constant  friction  of  the  tobacco — which  always  contains  more  or  less 


372  OPERATIVE   DENTISTRY. 

grit,  particularly  so  when  the  unprejiared  leaf  is  used,  as  by  the  negroes 
of  the  South — and  of  the  betel-nut  mixed  with  lime  rapidly  wears  away 
the  morsal  surfaces  of  the  teeth  employed  in  masticating  the  quid. 

The  writer  has  seen  several  cases  in  which  the  teeth  had  been  worn  to 
such  an  extent  by  this  process  that  they  did  not  meet  by  a  fourth  of  an 
inch. 

The  treatment  of  an  abrasion  is  the  same  as  that  employed  in  erosion 
and  attrition. 


CHAPTEE    XXIIL 

DISEASES  AND   INJURIES   OF   THE   DENTAL   PULP  AND   THEIE   TREATMENT. 

In  a  preceding  chapter  the  various  stages  of  caries  were  described,  and 
in  the  following  chapters  the  treatment  of  the  superficial,  progressive,  and 
deep-seated  stages  have  been  discussed.  It  now  remains  to  take  up  the  last 
or  complicated  stage  of  the  disease  ;  that  stage  in  which  the  carious  process 
has  penetrated  so  deeply  into  the  dentin  that  it  may  have  nearly  or  quite 
exposed  the  pulp  and  produced  irritation  and  pain  in  this  organ,  and 
possibly  jeopardized  its  vitality. 

The  pathology  of  the  dental  pulp  has  been  most  completely  studied  by 
"Wedl,  Salter,  and  Black,  and  nearly  all  of  the  knowledge  now  possessed 
upon  this  most  interesting  and  important  topic  has  come  to  us  as  a  result 
of  their  researches.  The  subject,  however,  still  remains  a  fruitful  field  for 
further  investigation,  for  many  problems  are  still  unsolved  and  many 
questions  need  further  elucidation. 

The  pathologic  changes  in  the  pulp  which  have  been  most  carefully 
studied  and  described  are  those  in  connection  with  hyperaemia,  inflamma- 
tion, secondary  deposits,  calcareous  and  fatty  degenerations. 

HYPEREMIA  OF  THE  DENTAL  PULP. 

Definition. — Hypersemia  (Greek,  uitip^  over;  al/xa^  blood),  a  condition 
of  plethora  or  congestion.  Hypersemia  of  the  dental  pulp  is  a  condition 
in  which  the  vessels  of  the  pulp  are  dilated  and  excessively  filled  with 
blood. 

Hypersemia  may  be  considered  as  the  most  important  pathologic  condi- 
tion to  which  the  pulp  is  subject,  for  the  reason  that  it  is  a  common  affec- 
tion and  often  terminates  in  the  destruction  of  the  organ.  Hypersemia 
may  be  transient  or  persistent,  its  character  dejjending  upon  the  nature, 
degree,  and  duration  of  the  irritation  which  induces  it. 

Irritation  is  the  state  of  a  tissue  or  an  organ  in  which  there  is  an  excess 
in  vital  movement,  commonly  manifested  by  increase  of  the  circulation 
and  of  the  sensitivity.  Irritation  in  some  form  always  precedes  hypersemia 
and  inflammation ;  or,  in  other  words,  these  conditions  are  always  caused 
by  some  form  of  irritation.  When  the  irritation  is  confined  to  a  particular 
portion  of  the  body  it  is  termed  local  irritation.  When  it  affects  the  whole 
system  it  is  termed  gcTieral  or  constitutional  irritation.  Hyperaemia  is  there- 
fore an  expression  of  a  state  of  irritation  which  may  be  either  local  or 
general. 

Hypersemia,  however,  may  be  a  physiologic  or  a  pathologic  condition. 

Flushing  of  the  cheeks  as  a  result  of  mental  excitement  produced  by  joy, 

shame,  or  anger  is  an  illustration  of  a  physiologic  hypersemia ;  while  the 

redness  following  a  local  irritation  would  more  nearly  express  a  pathologic 

hypersemia. 
^^  373 


374  OPERATIVE   PENTISTRY, 

Transient  hypercmiia  may  be  induced  as  an  accidental  condition  in  sound 
teeth  by  thermal  shock,  by  diminution  of  atmospheric  pressure,  such  as  is 
experienced  in  high  altitudes,  or  by  injuries  which  are  not  of  a  serious  na- 
ture but  sufficient  to  produce  a  congested  condition  of  the  pericemental 
membrane   and,  by  association    therewith,   transient    hypersemia   of   the 

pulj). 

This  condition  rarely  produces  more  than  a  mild  and  fleeting  sensation 
of  pain,  but  yet  is  a  sufficient  reminder  of  what  might  ensue  if  the  irrita- 
tion were  long  continued,  and  to  warn  the  individual  not  to  unnecessarily 
expose  himself  to  its  influence. 

Persistent  liypercemia  of  the  pulp  is  of  two  forms, — active  or  arterial  and 
•passive  or  venous. 

Active  hpyercemia  is  a  condition  in  which  the  arteries  and  capillaries 
of  the  pulp  are  excessively  filled  with  blood,  and,  as  a  result,  abnormally 
dilated. 

Passive  hypercemia,  or  venous  hypersemia  of  the  pulp,  is  a  condition  in 
which  the  veins  and  venules  suffer  engorgement  by  reason  of  compression 
at  the  apical  extremity  of  the  pulp-canal.  This  condition  is  indiiced  by 
irritation  and  a  consequent  increased  flow  of  blood  through  the  arteries, 
followed  by  their  dilatation  and  the  immigration  of  the  leucocytes.  Thus 
the  arteries  occupy  more  than  their  normal  space  in  the  canal,  while  the 
leucocytes  fill  the  meshes  of  the  connective  tissue  and  thus  produce  com- 
pression upon  the  veins  or  vessels  of  exit. 

The  susceptibility  of  the  pulp  to  external  irritation  varies  greatly  in 
different  individuals,  while  age,  temperament,  and  diathesis  play  an  im- 
portant part.  Susceptibility  to  irritation  is  much  greater  in  youth  than 
in  adult  life,  and  in  persons  of  high-strung  nervous  temperament  than  in 
the  phlegmatic.  Persons  of  a  tuberculous  or  syphilitic  diathesis  are  very 
susceptible  to  all  forms  of  irritation  and  prone  to  degenerative  tissue 
changes. 

Irritation,  on  the  other  hand,  is  well  known  to  be  a  prolific  cause  of 
new  formations,  provided  the  irritation  is  not  too  intense  in  character. 
Slight  irritations,  if  of  a  continuous  character,  often  result  in  hyperplasias 
of  tissue,  as,  for  instance,  in  the  increased  develojiment  of  cement-tissue  at 
the  apices  of  the  roots  of  teeth  which  have  been  subjected  to  the  irritation 
of  malocclusion,  the  strain  of  carrying  a  i)late  which  has  been  clasped  to 
them,  or  of  supporting  a  bridge  ;  while  if  the  irritation  is  excessive  it  is 
liable  to  produce  resorption  or  other  destructive  pathologic  changes.  This 
is  often  seen  in  the  roots  of  devitalized  teeth  which  are  in  a  septic  condi- 
tion or  are  the  seat  of  chronic  abscess. 

Again,  it  is  a  well-known  fact  that  owing  to  slight  irritations  of  the  dental 
pulp  from  such  causes  as  produce  a  slow  and  gradual  loss  of  the  hard  struc- 
tures of  the  teeth,  like  the  abrasions  of  mastication  or  of  metal  clasj)S  or  the 
erosion  of  the  enamel  at  the  cervical  margins  or  upon  the  labial  surfaces 
of  the  anterior  teeth,  or  from  slowly  progressing  caries,  secondary  deposits 
are  formed  in  th.e  pulp-chamber  opposite  the  point  of  irritation,  and  pro- 
ceed synchronously  with  the  destruction  of  the  external  tissues  until 
the  eiitire  coronal  portion  of  the  pulp-chamber  is  filled  and  the  crowns 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP.  375 

of  the  teeth  are  worn  down  to  the  gum.  If,  however,  the  process  of  de- 
struction is  rapid  the  pulp  is  soon  exposed,  and  hypersemia  and  inflamma- 
tion supervene,  thus  putting  an  end  to  all  chances  of  protecting  the  pulp 
by  new  formations,  as  such  growths  are  never  formed  when  acute  inflam- 
matory symptoms  are  present. 

Causes.— Hyperaemia  of  the  pulp  may  be  induced  by  many  and  varied 
forms  of  irritation,  both  local  and  constitutional. 

Local  Causes  of  Irritation. — These  may  be  divided  into  external^  or  those 
which  operate  from  without,  and  internal,  or  those  which  operate  from 
within,  the  pulp. 

External  Local  Causes. — Caries  in  its  various  stages  ;  traumatic  injuries  ; 
abrasions ;  erosions  ;  chemic  reactions  from  sweets,  acids,  etc. ;  excessive 
thermic  changes  ;  instrumentation  ;  mechanic  irritation  from  metallic  fill- 
ings ;  incompatibility  of  fillings ;  pressure  from  fillings  and  other  foreign 
substances  upon  the  thinned  walls  of  the  pulp-chamber  ;  galvanic  shock  ; 
septic  infection. 

Internal  Local  Causes. — Dentinal  tumors  ;  pulp-nodules. 

Constitutional  Causes. — Xervous  irritability  ;  plethora  ;  pregnancy. 

Hypermmia  from  External  Causes. — Caries  in  the  deep-seated  stage  is  the 
most  common  of  all  the  causes  of  irritation  which  produce  or  excite  a 
determination  of  blood  to  the  pulp,  resulting  in  hyperaemia.  Acute 
hyijersemia  may  occur  from  caries  in  any  of  its  stages,  but  most  frequently 
when  the  disease  has  progressed  so  far  as  to  nearly  expose  the  pulp,  or  it 
has  been  nearly  uncovered  by  a  traumatic  injury  or  by  abrasion  or  erosion. 
External  irritants,  like  thermal  shock  and  chemic  reactions,  are  usually  the 
exciting  causes  of  hyperaemia.  There  are,  nevertheless,  certain  individuals 
in  whom  general  nervous  irritability  and  local  hyperesthesia  may  be  so  greatly 
exalted  at  times  that  trivial  forms  of  irritation  become  unbearable.  Under 
such  circumstances  hyperaemia  of  the  pulp  may  be  induced  by  the  most 
Superficial  cavities  of  decay,  particularly  when  they  are  located  at  the 
cervix  of  the  tooth.  In  such  persons  the  introduction  of  metal  fillings, 
even  in  the  most  shallow  cavities,  are  frequently  jDroductive  of  a  persistent 
active  hyperaemia  and  severe  odontalgia,  necessitating  the  removal  of  the 
filling  before  relief  can  be  obtained,  while  if  the  filling  is  permitted  to 
remain  inflammationof  the  pulp  supervenes.  Irritability  of  this  character 
results  sooner  or  later,  according  to  the  intensity  of  the  hyperaemia  pro- 
duced, in  either  death  of  the  pulp,  the  formation  of  secondary  deposits  in 
the  form  of  dentinal  tumors,  or  pulp  nodules,  or  in  a  general  fatty  or 
calcareous  degeneration. 

On  the  other  hand,  secondary  formations  or  deposits  are  not  infre- 
quently found  within  the  pulp-tissue,  which  can  in  no  wise  be  accounted 
for  as  resulting  from  external  agencies,  and  which  are  sometimes  productive 
of  a  most  persistent  form  of  irritation,  accompanied  by  severe  neuralgic 
pains,  while  at  other  times  the  irritation  may  assume  a  low  chronic  form, 
resulting  in  various  obscure  reflex  symptoms. 

Chemic  reactions  from  sweets,  acids,  salt,  etc.,  taken  into  the  mouth  as 
food  or  condiments,  when  coming  in  contact  with  the  exposed  dentin  of  vital 
teeth,  may,  even  in  the  case  of  superficial  caries,  in  the  recession  of  the  gums 


376  OPERATIVE    DENTISTRY. 

which  exposes  tlie  cervices  of  the  teeth,  in  chemic  erosion  and  mechanic 
abrasions,  produce  a  persistent  hyperaemia  of  the  pulp,  the  nature  of  which 
is  determined  by  the  severity  and  duration  of  the  irritation,  the  excita- 
bility of  the  dentinal  fibrillse,  and  the  general  nervous  irritability  of  the 
individual. 

Excessive  thermic  changes  and  chemic  reaction,  operating  upon  the  ex- 
posed or  carious  dentin  of  vital  teeth,  are  the  most  frequent  exciting  causes 
of  hyperaerriia  of  the  pulp.  The  thermic  or  heat  sense  of  individual  teeth 
is  often  augmented  by  the  action  of  caries,  or  by  other  processes  or  injuries 
which  denude  the  dentin  of  its  natural  protecting  covering,  so  that  tem- 
peratures which  had  been  readily  tolerated  when  the  tooth  was  in  a  normal 
state  become  under  these  abnormal  conditions  painful  or  absolutely  in- 
tolerable ;  while,  upon  the  other  hand,  in  neurasthenic  individuals,  certain 
sound  teeth,  and  sometimes,  though  rarely,  all  of  the  teeth,  become  hyper- 
sensitive, so  that  the  pressure  of  mastication  is  no  longer  borne  with  com- 
fort, and  contact  with  foreign  substances  occurring  at  the  cervices  of  the 
teeth  or  at  points  unprotected  by  the  enamel  is  exceedingly  painful,  but  in 
which  the  degree  of  pressure  exerted  or  the  form  of  contact  does  not  seem 
to  hold  any  relation  to  the  amount  or  the  character  of  the  pain  induced. 
The  same  is  true  of  thermic  changes ;  the  differences  in  the  degree  of  heat 
and  cold  beyond  the  point  of  toleration  do  not  seem  to  make  any  especial 
difference  in  the  intensity  of  the  pain.  In  the  former  condition  hypersemia 
may  be  induced  as  a  consequence  of  irritation,  and  the  pulp,  if  examined 
at  the  time,  will  be  found  to  be  passing  into  a  state  of  disorganization  ; 
while  in  the  latter,  if  the  offending  tooth  is  extracted,  macroscopic  and 
microscopic  examination  may  fail  to  discover  any  structural  changes  what- 
ever in  the  pulp  or  the  calcified  tissues  of  the  tooth. 

Instrumentation,  such  as  is  employed  in  the  excavation  of  a  hypersensi- 
tive cavity  of  decay,  is  often  very  painful,  and  the  irritation  induced  by 
the  i)rocess  will,  in  certain  individuals  of  exalted  nervous  irritability,  pro- 
duce an  active  hyperaemia  of  the  pulp.  A  common  form  of  irritative 
instrumentation,  and  one  which  more  often  results  in  producing  active 
hypersemia,  is  that  caused  by  the  friction  of  rapidly  revolving  engine  burs 
and  disks,  which  are  permitted  to  heat  the  tooth  beyond  the  limit  of  nor- 
mal toleration.  The  friction  induced  by  the  rapidly  revolving  bur  may  be 
prevented  by  causing  a  stream  of  tepid  water  to  flow  over  it  from  a  syringe, 
while  the  friction  and  consequent  heating  of  the  tooth  iji  finishing  a  filling 
with  sand-paper  and  cuttle-fish  disks  may  be  greatly  lessened  by  lubricating 
the  surface  with  toilet  soap  or  vaseline. 

Incompatibility  of  metal  fillings  with  the  structures  of  the  teeth  is  often 
productive  of  serious  annoyance  from  the  irritation  produced  by  the  pres- 
ence of  the  foreign  body  in  the  hard  structures  of  the  tooth,  for  such  it 
must  be  considered  under  these  circumstances. 

Hypereemia  of  the  pulp  which  is  induced  by  the  presence  of  metallic 
fillings  in  the  tooth  is  due,  as  already  intimated,  to  a  peculiar  and  exalted 
general  nervous  susceptibility  of  the  individual  to  various  forms  of  irrita- 
tion, and  to  an  excessive  excitability  or  irritability  of  the  dentinal  fibrillje, 
which  makes  them  intolerant  of  all  foreign  substances  used  as  filling- 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP.  377 

materials,  wliicli  are  very  far  removed  from  the  dentin  in  their  power  to 
carry  caloric  impressions  and  electric  currents.  This  is  proved  by  the  fact 
that  such  teeth  which  have  been  filled  with  metals  are  soon  made  entirely 
comfortable  by  the  removal  of  the  metallic  fillings  and  substituting  gutta- 
percha or  porcelain  inlays. 

Pressure  of  fillings  is  sometimes  a  cause  of  irritation  of  the  pulp,  and 
is  rapidly  followed  by  acute  or  active  hyperaemia.  Pressure  sufficient  to 
cause  Irritation  can  only  occur  in  those  cases  in  which  the  layer  of  dentin 
covei'ing  the  pulp  is  vqvj  thin,  or  so  considerably  decalcified  as  to  cause 
it  to  bend  under  the  stress  of  the  force  used  in  packing  the  filling  into  the 
cavity. 

Hypertemia  which  is  caused  by  this  form  of  irritation  rapidly  pro- 
gresses to  congestion  and  partial  stasis,  accompanied  by  excruciating  throb- 
bing pain,  and  later  ending  in  strangulation  of  the  apical  vessels  and  death 
of  the  pulp,  unless  the  filling  is  immediately  removed  and  the  irritation 
allayed  hy  local  applications  to  the  pulp  of  soothing  or  anodyne  drugs, 
like  the  tincture  of  opium,  morphine,  or  cocaine. 

If,  however,  continuous  pain  has  been  present  for  more  than  two  or 
three  days,  conservative  treatment  of  the  pulp  will  usually  prove  unavail- 
ing for  the  reason  that  the  irritation  has  been  so  violent  as  to  completely 
overcome  the  resistive  powers  of  the  pulp  and  render  recuperation  nearly, 
if  not  quite,  impossible.  Devitalization  then  becomes  the  only  means  of 
giving  comfort  to  the  patient  and  preserving  the  tooth. 

Galvanic  shocJc  is  another  and  not  infrequent  cause  of  irritation  and 
hypersemia  of  the  pulp.  This  form  of  irritation  is  produced  in  the  mouth 
by  the  contact  of  dissimilar  metals,  the  surfaces  of  which  are  bathed  with 
saliva  having  a  slightly  acid  reaction,  as,  for  instance,  the  contact  of  gold 
and  amalgam  fillings  in  occluding  teeth,  or  in  the  approximating  surfaces 
of  teeth  which  are  not  in  close  contact,  but  which  by  the  occasional  suspen- 
sion of  food  debris  or  the  oral  secretions  make  and  break  the  circuit  during 
the  acts  of  mastication,  speech,  deglutition,  or  in  other  movements  of  the 
jaws,  tongue,  and  the  muscles  of  mastication.  Metal  iDlates  occasionally  pro- 
duce the  same  effects  when  in  contact  with  fillings  of  a  different  potential. 
Fillings  composed  of  metals  of  a  different  potential  placed  in  the  same 
cavity  do  not — even  when  moisture  can  penetrate  between  them — produce 
galvanic  shock,  for  the  reason  that  the  galvanic  current  established  be- 
tween them  is  continuous,  and  without  the  presence  of  moisture  it  would 
be  very  slight  indeed,  except  upon  the  exposed  surfaces,  and  this  soon 
ceases  from  the  gradual  oxidation  of  the  surface  of  the  baser  metal,  ^¥hen 
gold  and  amalgam  are  placed  in  the  morsal  surface  of  the  same  tooth,  but 
in  cavities  separated  by  a  more  or  less  thin  wall  of  dental  tissue,  painful 
galvanic  shock  sometimes  occurs  during  the  act  of  mastication,  by  the 
current  being  completed  and  broken  by  the  contact  of  masses  of  food 
which  are  so  placed  at  the  time  as  to  form  a  connection  or  circuit  between 
the  two  fillings. 

Another  source  of  galvanic  shock  is  the  contact  of  a  table  fork,  knife,  or 
spoon  with  a  gold  or  a  bright  amalgam  filling ;  such  shock  is  sometimes 
very  painful. 


378  OPEKATIVE    DENTISTRY. 

The  character  of  the  hypersemia  produced  by  galvanic  shock  will 
depend  in  large  measure  upon  the  intensity  and  the  frequency  with 
which  the  shocks  occur  and  the  susceptibility  of  the  individual  to  such 
form  of  irritation.  In  the  one  case  it  may  result  in  acute  hyperaemia 
and  severe  attacks  of  odontalgia,  while  in  another  it  may  develop  a  pas- 
sive or  chronic  hyperaemia  with  calcareous  deposits  or  other  degenerative 
changes. 

The  treatment  of  this  form  of  irritation  should  be,  invariably,  the  removal 
of  one  of  the  offending  fillings  and  replacing  it  with  a  metal  like  the  other, 
or  with  a  material  possessing  no  conducting  or  electric  properties,  like 
gutta-i>ercha  or  zinc  phosphate. 

Septic  infection  is  often  a  source  of  acute  hypersBmia  of  the  pulp.  This 
is  commonly  caused  by  the  invasion  of  the  pulp-chamber  by  the  disin- 
tegrating processes  of  caries.  It,  however  not  infrequently  occurs  in 
those  cases  in  which  the  pulp  has  not  been  exposed,  but  is  still  covered 
with  a  layer  of  decalcified  and  softened  dentin  (pseudo-exposure),  the 
tubuli  of  which  are  filled  with  saprophytic  and  pyogenic  organisms  which 
readily  penetrate  to  the  pulp  and  establish  sej)tic  irritation,  inflammation, 
suppuration,  and  devitalization.  A  thin  layer  of  sound  dentin  is  a  posi- 
tive external  protection  against  the  infection  of  the  pulp  with  the  pyogenic 
organisms. 

It  is  nevertheless  possible  for  suppurative  conditions  to  be  established 
in  the  pulj)  without  direct  external  infection.  The  presence  of  j^yogenic 
organisms  in  the  blood- current  which  may  have  gained  an  entrance  through 
some  abrasion  of  the  skin  or  mucous  membrane,  or  through  a  wound,  or 
pre-existing  abscess,  has  long  been  recognized.  These  are  capable  when 
they  become  arrested  in  a  vessel  of  rapidly  propagating  and  overcoming 
the  vis  naiurce  of  the  surrounding  tissues  and  establishing  suppurative  con- 
ditions. This  explains  the  presence  of  abscesses  of  the  pulp  which  are 
occasionally  found  in  perfectly  sound  teeth,  the  contents  of  the  pulp- 
chamber  having  the  appearance  of  the  pus  found  in  cold  abscesses,  and 
which,  like  the  cold  abscesses  found  in  the  bones  and  soft  tissues  of  tuber- 
cular individuals,  have  not  and  do  not  present  any  acute  symx)toms  until 
they  are  opened,  when,  if  the  utmost  aseptic  precautions  are  not  observed, 
they  sometimes  take  on  most  violent  inflammatory  conditions  which  may, 
in  extreme  cases,  terminate  in  the  loss  of  the  tooth  and  in  establishing 
acute  septicaemia. 

Symptoms. — The  symptoms  of  active  or  acute  hyperaemia  of  the 
pulj)  are  sharp,  lancinating  pains,  produced  by  hot  or  cold  substances 
coming  into  contact  with  a  vital  tooth  which  has  been  partially  de- 
stroyed by  caries,  traumatic  injury,  abrasion,  or  erosion,  or  which  con- 
tains a  metal  filling,  or  by  the  contact  of  sweet  or  acid  substances  with 
the  denuded  surface.  So  long  as  the  shock  of  irritation  of  these  agencies 
produces  a  quick,  sharp,  and  transient  paroxysm  of  pain,  which  reap- 
pears only  upon  an  application  of  the  irritation,  it  may  be  safely  in- 
ferred that  no  serious  vascular  disturbance  is  present ;  but  when  the 
paroxysms  of  pain  are  not  only  sharp  and  lancinating,  but  prolonged  for 
several  minutes  or  even  hours  after  contact  with  these  irritating  agencies, 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP.  379 

it  may  be  suspected  that  serious  disturbances  are  taking  place  iu  the  ves- 
sels of  the  pulp. 

Slight  tenderness  to  percussion  or  to  forcible  occlusion  is  often  a  sub- 
jective symptom.  This  is  due,  in  all  probability,  to  an  associated  sympa- 
thetic hypersemia  of  the  pericemental  vessels  surrounding  the  apex  of  the 
root.  The  pain,  in  the  absence  of  active  irritation,  is  usually  diffused  over 
the  entire  side  of  the  jaw  and  but  vaguely  located,  and  may  be  referred  by 
the  patient  to  an  adjoining  tooth  or  to  one  in  the  immediate  neighborhood. 
Sometimes  the  pain  is  reflected  to  a  tooth  upon  the  same  side  of  the  jaw- 
but  remote  from  the  seat  of  trouble,  or  it  may  be  reflected  to  the  corre- 
si)onding  tooth  or  some  other  in  the  opposite  jaw.  Occasionally  this  symp- 
tom will  assume  a  neuralgic  character,  the  pain  being  located  in  the  ear, 
or  it  may  manifest  itself  in  the  ophthalmic  division  of  the  fifth  nerve  and 
produce  lachrymation,  hypersemia,  or  inflammation  of  the  conjunctiva,  and 
even  amaurosis.  "When  the  pain  is  neuralgic  in  character  the  "points 
douloureux"  of  Valliex  are  often  well  marked  in  the  trifacial  nerve.  In 
the  oplithahnic  division  these  tender  points  are  located  at  the  supraorbital 
foramen,  the  upper  eyelid  at  the  line  of  union  of  the  nasal  bone  witli  the 
cartilage,  at  the  inner  angle  of  the  orbit,  and  in  the  globe  of  the  eye. 
Another  i)oint  is  near  the  i^arietal  eminence. 

In  the  superior  maxillary  division  the  tender  j^oints  are  situated  at  the 
infraorbital  foramen,  at  the  point  over  the  most  prominent  part  of  the 
malar  bone,  an  uncertain  point  upon  the  gum  of  the  superior  maxilla,  a 
similar  point  upon  the  upper  li]3,  and  another  upon  the  j)alate. 

In  the  inferior  maxillary  division  the  tender  points  are  found  over  the 
auriculo-temporal  branch  just  in  front  of  the  ear  ;  another  is  located  over 
the  inferior  dental  foramen,  and  still  another  over  the  mental  foramen. 

Diagnosis. — Diagnosis  in  even  the  most  obscure  cases  of  hyperaemia 
of  the  pulp  can  usually  be  made  by  forcing  a  jet  of  cold  air  into  the  cavity 
from  a  chip-blower,  or  by  the  application  of  a  jet  of  cold  water  having  a 
temperature  not  lower  than  60°  F.,  thrown  from  a  syringe  upon  the  suspected 
tooth.  In  the  absence  of  a  cavity,  fillings  should  be  sought  for  and  tested 
by  the  same  means.  Failing  with  these,  hot  water  maj^  be  used  in  the 
same  manner.  Or  the  positive  pole  of  the  galvanic  current  may  be  ap- 
plied. As  a  rule,  the  application  of  any  one  of  these  methods  will  render 
the  diagnosis  sure  by  immediately  stimulating  a  responsive  twinge  of  pain. 
More  rigorous  means  will  excite  a  severe  paroxysm  of  pain  in  the  offending 
tooth  and  aggravate  the  neuralgic  symptoms. 

Pathology. — The  principal  and  characteristic  pathologic  change  which 
takes  place  in  active  hyx)eraemia  of  the  pulp  is  an  irregidar  dilatation  of  its 
Mood-vessels.  Salter  *  (1875)  was  the  first  to  discover  this  peculiarity  of  the 
vessels  of  the  pulp  while  studying  the  pathology  of  suppurating  and 
sloughing  pulps.  He  describes  the  condition  as  an  irregular  dilatation  of 
the  smaller  vessels  into  ampullse  filled  with  clots,  and  which  he  believed  to 
be  due  to  engorgement  of  the  vessels,  loss  of  vital  contractility,  passive 
yielding  of  the  over-distended  and  thinned  walls,  and  coagulation  of  the 


*  Dental  Pathology  and  Surgery. 


380 


OPERATIVE    DENTISTRY. 


blood.     Albrecht*(lS5S)  called  attention  to  the  notable  increase  in  the 
volume  of  the  blood  vessels  and  to  their  tortuous  course.     Wedl  f  (1870) 


Fig.  484. 


Hypersemia  of  the  dental  pulp,  showing  the  natural  injection  of  the  vessels,  (After  Black.)  a,  a, 
membrana  eboris,  orla.ver  of  odontoblasts;  6,  6,  6,  b,  vessels  distended  with  blood  ;  c,  c.  c.  c,  points  from 
which  the  blood  has  fallen  in  handling  the  section. 

also  describes  a  swollen  and  lax  condition  of  the  fibrous  sheaths  of  the 

small  arteries  and  veins. 

Fig.  485. 


Dilated  blood-vessels  from  the  dental  pulp  in  hyperemia,  from  tooth  extracted  during  a  paroxysm  of 

intense  pain.     (After  Black.) 

Black  I  (1886)  found  the  dilated  and  varicosed  condition  of  the  vessels 
of  the  pulp  (Fig.  484)  to  be  so  constant  as  to  form  a  characteristic  patho- 


*  Krankheiter  der  Zahnpulpe. 
J  American  System  of  Dentistry. 


t  Pathology  of  the  Teeth. 


DISEASES    AND    INJURIES    OF   THE    DENTAL    PULP.  381 

logic  feature  of  the  acute  form  of  the  affection.  Fig.  485  was  made  by  Dr. 
Black  from  a  section  of  the  pulp  of  a  tooth  which  was  extracted  during  a 
paroxysm  of  acute  pain.  The  tooth  had  been  troubling  for  several  weeks, 
the  paroxysms  of  pain  being  excited  by  very  trivial  changes  in  tempera- 
ture and  lasting  for  an  hour  or  more.  He  also  found  in  other  cases  of  a 
similar  character,  but  which  were  extracted  during  an  interval  between 
the  paroxysms  of  pain,  that  nothing  of  a  remarkable  character  was  pre- 
sented. The  veins  of  a  bulbous  portion  of  the  pulp  may  be  abnormally 
large  and  engorged  with  blood,  while  the  arteries  will  be  almost  or  quite 
empty  and  the  injection  of  the  capillary  system  wanting.  Black  looks 
upon  the  increased  susceptibility  of  the  pulp  to  thermal  shock  as  "in  a 
large  degree  due  to  nervous  phenomena.  The  tension  of  the  blood-vessels 
and  their  degree  of  contractibility  are  phenomena  which  are  controlled  by 
the  vasomotor  system,  and  in  the  dental  pulp  these  are  prominently 
affected  by  thermal  changes  in  such  a  way  that  the  vessels  expand  passively 
before  the  j^ressure  of  the  circulation," 

The  dilatation  of  the  vessels  is  due  to  a  paralysis  of  the  vaso-constrictor 
fibres,  and  the  varicosed  condition  to  an  irregular  paralysis  of  these  fibres. 
The  effect  of  painful  stimulation  or  irritation  upon  the  vasomotor  system 
of  nerves  is  to  cause  an  immediate  contraction  of  the  vasoconstrictor 
fibres  of  the  walls  of  the  vessels  and  narrowing  of  their  lumen ;  this  is 
followed  by  reaction  and  stimulation  of  the  vasodilator  fibres,  which 
cause  a  dilatation  of  the  lumen  of  the  vessel,  and  permit  a  greater  quan- 
tity of  blood  to  flow  through  it  than  is  normal,  which  constitutes  a  transi- 
tory hypersemia.  In  persistent  hyperemia  of  a  pronounced  type  the 
vasoconstrictor  fibres  suffer  paralysis  for  a  time,  -resulting  in  a  continued 
expansion  of  the  vessels,  which  may  become  permanent  if  the  irritation  is 
of  a  continuous  character. 

Black  found  as  a  result  of  his  researches  that  the  vessels  of  the  pulp 
possessed  a  wonderful  degree  of  recuperative  power,  and  that  the  vessel 
walls  frequently  recover  their  normal  tonicity. 

In  the  more  advanced  stage  of  arterial  hyperjDemia  another  phenomenon 
is  sometimes  presented.  This  is  the  escape  or  migration  of  the  red  blood- 
corpuscles  through  the  walls  of  the  vessels,  forming  areas  of  a  reddish 
hue,  and  in  other  instances  of  deeper  color,  having  the  appearance  of  ex- 
travasations of  blood.  These  are  in  all  probability  due  to  embolism  and 
the  formation  of  an  infarct.  An  infarct  is  a  dark-red,  wedge-shaped  area 
in  an  organ  due  to  the  occlusion  of  a  vessel  by  an  embolus,  with  the  sub- 
sequent extravasation  of  blood  into  the  tissues  beyond  the  point  of  obstruc- 
tion. The  base  of  the  wedge  is  towards  the  periphery  of  the  organ,  and 
the  apex  towards  the  point  from  which  the  blood-clot  entered  the  obstructed 
vessel. 

Passive  or  venous  hypercemia  can  only  be  inferred  from  the  character  of 
its  symptoms,  which  are  dull,  heavy,  gnawing  pains,  accompanied  by  a 
sense  of  fulness,  the  intensity  of  the  pain  often  being  steadily  maintained 
for  many  hours.  These  symptoms  are  probably  due  to  the  dilatation  of 
the  arteries  which  enter  at  the -apical  foramen,  causing  pressure  upon  the 
veins  and  pieventing  the  escape  of  the  blood  from  the  pulp  by  these  chan- 


382  OPERATIVE    DENTISTRY. 

nels.  In  teetli  possessing  two  or  more  roots,  the  liypersemia  may  be  some- 
what lessened  by  the  escape  of  the  blood  through  the  veins  of  a  second 
root.  In  single-rooted  teeth  this  cannot  occur,  and  if  the  congestion  ex- 
tends to  the  apex  of  the  tooth,  the  pain  will  continue  until  strangulation  or 
general  infarction  takes  place. 

Prognosis. — Hypersemia  from  external  irritants,  if  unrelieved,  usually 
leads  to  diffuse  inflammation  of  the  pulp,  probably  as  a  result  of  infarc- 
tion and  the  extravasation  of  the  red  blood-cori)uscles.  Cohnheim's  ex- 
periments seem  conclusive  that  inflammation  does  not  result  from  even  the 
most  extreme  hyperiemia  that  can  be  induced  by  the  jDaralysis  of  the  vaso- 
motor nerves.  Black  *  was  not  able  to  determine  whether  diffuse  inflam- 
mation would  occur  before  infarction  and  extravasation  had  taken  place 
or  not,  but  was  inclined  to  believe  with  Cohnheim  that  it  would  not.  His 
own  observations,  however,  show  conclusively  that  in  every  case  of  ex- 
travasation a  mild  form  of  inflammatory  action  had  been  induced,  by 
which  new  elements  were  thrown  out  which  acted  the  part  of  absorbents 
in  the  removal  of  the  extravasated  blood,  and  in  this  way  he  believes  a 
general  diffuse  inflammation  of  the  pulp  may  be  set  u]3  as  a  result  of 
hypersemia.  He  thinks  this  will  exj)laiu  those  cases  of  diffuse  inflamma- 
tion of  the  pulp  which  often  occur  without  the  exposure  of  the  organ  to 
any  of  the  forms  of  external  irritation. 

Absorption  of  the  extravasated  red  blood-corpuscles  takes  place  through 
the  phagocytic  action  of  the  leucocytes. 

The  progress  of  active  hypersemia  will  depend  upon  the  temperament 
and  the  general  health  of  the  patient,  the  duration  and  character  of  the 
irritation,  the  severity  and  frequency  of  the  paroxysms  of  i)ain,  and  the 
extent  to  which  the  crown  of  the  tooth  has  been  destroyed  by  caries  or 
other  causes. 

The  power  of  the  pulp  to  recover  after  repeated  attacks  of  hypersemia 
points  strongly  to  a  favorable  prognosis  in  those  cases  which  have  escaped 
infarction  and  septic  infection  ;  provided  the  temperament,  age,  and  the 
general  health  of  the  individual  do  not  operate  against  it. 

Conservative  treatment  should  therefore  be  adopted  in  all  cases  in 
which  a  favorable  prognosis  may  be  hoped  for.  It  is  not  to  be  expected, 
however,  that  every  case  so  treated  will  prove  successful,  any  more  than 
that  one  should  expect  every  case  in  which  the  pulp  is  removed  to  prove 
successful.  A  certain  number  will  prove  failures  in  either  case,  but  the 
percentage  of  successes  and  failures  will  depend  (after  the  individual 
equation  of  the  patient  has  been  eliminated  from  the  proposition)  very 
largely  upon  the  diagnostic  ability  and  manipulative  skill  of  the  operator, 
coupled  with  good  judgment  in  the  selection  of  the  particular  method  of 
treatment  to  be  employed. 

The  writer  maintains  that  inasmuch  as  the  pulp  of  the  fully  calcified 
tooth  is  its  organ  of  nutrition  and  sensation,  it  has  two  important  functions 
to  fulfil, — functions  which  should  be  preserved  as  long  as  jDOSsible,  that  the 
tooth  may  perform  to  completion  its  many  ofiices  as  nature  intended  ;  and 

*  American  System  of  Dentistry. 


DISEASES    AND    INJURIES    OF   THE    DENTAL    PULP.  383 

furthermore,  that  the  pulj:*  should  uever  be  ruthlessly  destroyed,  because, 
forsooth,  it  has  souuded  au  alarm  ou  the  too  near  approach  to  its  citadel 
of  the  arch-enemy,  dental  caries. 

Many  operators  look  upon  all  efforts  to  conserve  the  vitality  of  the 
pulp,  after  it  has  given  evidence  of  being  the  seat  of  hyperemia,  as  largely 
experimental,  with  the  chances  of  failure  very  greatly  in  the  ascendency, 
and  for  this  reason  advise  devitalization  and  extirpation  as  the  surest  way 
of  rendering  the  tooth  comfortable. 

Other  equally  skilful  and  conscientious  operators  attempt  the  con- 
servation of  the  pulp  even  after  it  has  been  the  seat  of  hypersemia  for 
several  days,  and  succeed  in  a  good  per  cent,  of  cases  in  preserving  their 
vitality,  as  pi'oved  by  their  responding  to  the  usual  tests  many  years  after- 
wards. 

The  age  and  the  general  health  of  the  patient  are  important  factors  in  the 
recuperative  powers  of  the  pulp.  Conservative  treatment  of  the  pulp  is 
much  more  likely  to  prove  successful  in  youth  and  early  adult  life  than  in 
middle  life  or  old  age,  while  in  the  debilitated  or  those  suffering  from 
tuberculosis  or  other  infectious  diseases  the  prognosis  is  very  unfavorable. 

Treatment. — The  rational  treatment  of  any  surgical  disease  or  injury 
comprehends  two  general  principles  :  first,  the  removal  of  the  cause ;  and 
second,  rest  of  the  organ  or  part  which  should  approach  complete  physiologic 
rest  as  nearly  as  possible.  These  principles  should  always  be  carried  out  in 
the  treatment  of  dental  diseases,  for  they  can  be  as  readily  applied  in  this 
class  of  diseases  as  they  can  in  the  more  serious  surgical  diseases  or 
injuries. 

In  the  treatment  of  hypersemia  of  the  pulj),  the  first  effort  should  be 
directed  towards  giving  relief  from  the  pain,  and  this  can  best  be  accom- 
plished by  the  removal  of  the  cause  of  irritation.  When  the  disturbance 
to  the  pulp  arises  through  a  carious  cavity  in  the  tooth,  this  should  be 
freed  from  food  debris  by  carefully  syringing  the  cavity  with  tepid  water 
to  which  has  been  added  in  proper  strength  a  suitable  alkali  or  an  anti- 
septic. Bicarbonate  of  soda  is  the  best  alkali  for  the  purpose,  and  listerine, 
pasteurine,  borolyjitol,  thymolene,  and  formol  are  the  best  of  the  i)repai'ed 
antiseptics.  The  simple  removal  of  the  dShris  and  neutralizing  the  acid 
condition  of  the  disorganized  dentin  will  often  be  all  that  will  be  required 
to  give  immediate  relief  from  the  pain.  The  next  step  is  to  remove  the  dis- 
organized dentin,  care  being  taken  not  to  expose  the  pulp,  as  an  accident 
of  this  character  complicates  the  treatment  and  renders  the  prognosis  of  the 
case  somewhat  more  doubtful. 

The  writer  believes  with  many  other  practitioners  of  somewhat  ex- 
tended experience  that  it  is  better  practice  to  leave  a  layer  of  decalcified 
dentin  over  a  living  but  hyperaemic  pulj)  than  to  remove  this  covering  and 
substitute  for  it  a  foreign  substance,  which  can  by  no  possible  stretch  of 
the  imagination  be  thought  to  be  as  compatible  to  the  pulp  as  the  tissue — 
though  partially  disorganized — which  nature  formed  for  its  protection  ;  and 
for  the  further  reason  that  such  practice  gives  better  results,  in  conserving 
the  organ,  than  does  capping  with  a  foreign  substance. 

The  cavity  should  now  be  dressed  with  some  remedy  possessing  sedative 


384  OPERATIVE    DENTISTRY. 

and  antiseptic  qiialitiesi;  like  the  oils  of  cloves,  cinnamon,  tliyme,  gaul- 
theria,  peppermint,  etc.,  applied  upon  a  pledget  of  cotton  and  sealed  in 
with  temporary  stopping  or  zinc  oxyphosphate.  Carbolic  acid  is  recom- 
mended by  some  operators,  while  others  object  to  its  use  because  of  its 
coagulating  effect  upon  the  albuminoids  of  animal  tissue.  The  object  in 
sealing  the  dressing  into  the  cavity  with  these  substances  is  to  secure  rest 
to  the  pulp  by  preventing  or  lessening  thermal  shock,  and  also  to  prevent 
its  further  contamination  with  septic  material,  as  by  this  method  only  can 
one  expect  to  succeed  in  permanently  allaying  the  irritation  of  the  pulp 
and  reducing  its  hyperaemic  condition.  Plugs  formed  of  cotton  saturated 
with  gum  sandarach  cannot  fulfil  these  requirements,  for  they  soon  become 
saturated  with  the  secretions  of  the  mouth  and  filled  with  myriads  of  or- 
ganisms, and  should,  therefore,  never  be  employed  in  any  case  where 
the  maintenance  of  aseptic  conditions  are  desirable. 

The  dressings  should  be  allowed  to  remain  undisturbed  for  two  or  three 
days  or  longer  if  the  tooth  continues  comfortable,  otherwise  they  may 
be  changed  every  day.  Care  should  be  exercised  in  applying  the  dressing, 
and  in  each  after-treatment,  to  prevent  the  entrance  of  moisture  from  the 
mouth.  To  insure  this  condition  it  is  better  to  resort  to  the  rubber  dam 
than  to  rely  upon  napkins  or  other  means  for  excluding  moisture.  If  after 
a  week's  treatment  the  tooth  remains  in  a  comfortable  condition,  the  pulp 
may  be  protected  from  thermal  shock  by  varnishing  the  cavity  and  placing 
a  layer  of  softened  gutta-percha  in  the  bottom  of  the  cavity,  and  filling  the 
balance  with  zinc  oxyphosphate,  or  thin  zinc  oxyphosphate  may  be  flowed 
over  the  bottom  of  the  cavity  and  the  balance  filled  with  gutta-percha. 

The  treatment  of  exposed  pulps  is  given  in  a  following  chapter  upon 
this  subject. 

In  those  cases  in  which  the  hyiDcraemia  is  associated  with  abrasions, 
erosions,  or  superficial  cavities  the  surfaces  may  be  treated  with  carbolic 
acid  (deliquesced  crystals)  or  caustic  potassa  when  located  in  the  anterior 
part  of  the  mouth,  or  with  silver  nitrate  when  located  in  unexj)osed  posi- 
tions. Or  a  retentive  form  may  be  given  to  the  denuded  surface,  the  cavity 
thus  made  being  first  treated  with  carbolic  acid  and  then  dried,  varnished, 
and  filled  with  zinc  oxyphosphate. 

When  the  irritation  and  hypertemia  are  due  to  the  presence  of  large 
metallic  fillings  or  to  galvanic  shock  from  contact  of  fillings  of  dissimilar 
metals,  these  should  invariably  be  removed  and  replaced  with  non-con- 
ducting materials. 

Hyperaemia  from  Internal  Local  Causes. — Hypertemia  of  the  pulp 
may  be  induced  by  certain  internal  causes, — viz.,  the  formation  of  secondary 
growths  within  the  pulp-chamber  or  within  the  parenchyma  of  the  pulp 
itself. 

These  growths  are  designated  as  dentinal  tumors  and  pulp-nodules. 

Calcifications  of  the  pulp  resulting  from  the  irritation  of  caries  and 
other  destructive  loss  of  the  hard  tissues,  and  calcareous  degeneration,  are 
rarely,  if  ever,  causes  of  hypersemia  of  the  pulp,  but  are  quite  often  the 
results  of  hypersemia. 

These  formations  have,  however,  been  frequently  found  in  teeth  which 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP.  385 

had  given  no  history  of  irritation  or  pain ;  it  has,  therefore,  been  ques- 
tioned whether  they  are  ever  sources  of  hypersemia.  Some  have  thought 
them  to  be  the  result  of  irritation  and  hypersemia,  while  others  have  be- 
lieved they  may  sometimes  not  only  be  the  cause  of  this  disturbance,  but 
the  more  serious  condition  of  facial  neuralgia. 

This  form  of  hypersemia  is  sometimes  termed  idiopathic,  for  the  reason 
that  there  seemed  to  be  no  other  disease  uj^on  which  it  was  dependent  for 
its  origin  or  j^rogress.  In  a  certain  number  of  these  cases  there  is  not  the 
slightest  evidence  of  any  external  form  of  irritation  whatever.  In  fact, 
the  teeth  are  perfectly  sound,  the  most  careful  examination  failing  to  reveal 
the  minutest  trace  of  a  break  in  the  continuity  of  the  enamel,  either  from 
caries,  abrasion,  erosion,  or  other  injury.  We  must,  therefore,  in  these 
cases,  look  for  internal  causes  of  irritation  which  are  to  be  found  in  the 
presence  of  dentinal  tumors  and  pulp-nodules.  There  are,  however,  no 
symptoms  which  are  particularly  or  peculiarly  diagnostic  of  these  forms 
of  irritation.  The  diagnosis  must  therefore  be  reached  by  a  process  of 
exclusion. 

The  prognosis  is  decidedly  unfavorable  in  this  class  of  cases  so  far  as 'the 
vitality  of  the  pulp  is  concerned,  for  sooner  or  later  the  pulp  succumbs  to 
the  irritation  and  devitalization  takes  place. 

Treatment. — The  treatment  of  hypersemia  due  to  irritation  produced 
by  the  presence  of  secondary  deposits  within  the  pulp-chamber  to  be  cura- 
tive must  he  radical.  This  consists  of  devitalizing  and  extirpating  the 
pulp  and  filling  the  canals  with  suitable  materials. 

Hyperaemia  from  Constitutional  Causes. — General  nervous  irri- 
tability  or  neurasthenia  is  a  term  which  has  come  into  general  use  to  indicate 
certain  states  of  the  nervous  system — often  inherited — the  anatomic  basis 
of  which  is  still  unknown,  but  which  are  characterized  upon  the  one  hand, 
as  pointed  out  by  Putnam,  by  a  series  of  negative  symj^toms  manifested  by 
a  lack  of  vigor,  efficiency,  and  endurance,  affecting  usually  a  large  num- 
ber of  nervous  functions,  and,  upon  the  other  hand,  by  signs  of  active 
derangement,  which  in  part  seem  to  occur  as  positive  symptoms,  and  in 
part  are  due  to  a  failure  of  the  mutual  support  and  control  which  the  dif- 
ferent parts  of  the  nervous  systeni  afford  each  other  in  health.  These  con- 
ditions are  often  manifest  in  the  mentally  and  ]3hysically  overworked,  in 
low  conditions  of  the  general  health,  particularly  in  ansemic  states  of  the 
blood,  and  in  those  suffering  from  prolonged  wasting  diseases,  like  tuber- 
culosis and  cancer,  or  from  digestive  or  intestinal  derangements  and  fi'om 
nervous  shock. 

I>feurasthenic  i^atieuts  are  also  subject  to  various  sensory  disorders  like 
neu]'algic  attacks  and  periodic  headaches.  Irritability  of  the  spinal  cord, 
which  upon  pressure  xjroduces  painful  peripheral  sensations  in  the  region 
of  the  thorax  or  abdomen,  according  to  the  level  at  which  the  pressure  is 
made.  x\nother  quite  common  variety  of  painful  sensation,  not  precisely 
neuralgic  in  character,  is  a  distressing  sense  of  pressure  and  tenderness  at 
the  vertex  or  occiput,  with  stiffness  of  the  muscles  of  the  neck.  Occasion- 
ally the  pain  is  very  severe,  and  entirely  unfits  the  individual  for  the  time 
for  any  form  of  physical  or  mental  labor. 

25 


386  OPERATIVE    DENTISTRY. 

Dr.  Allbutt,  in  speaking  of  this  class  of  individuals,  says,  ''They  are 
heirs  of  every  true  neurosis,  from  insanity  to  toothache." 

Ilypercesthetic  conditions  of  the  peripheral  terminations  of  the  nerves, 
especially  of  the  skin,  are  frequently  met  with  in  neurasthenic  individuals. 
These  conditions  are  characterized  by  an  exalted  or  exaggerated  sensibility 
of  the  skin,  which  is  unattended  by  any  observable  structural  changes 
whatever.  In  mild  cases  there  is  manifested  an  undue  sensitiveness  to 
contact  with  foreign  bodies,  such  as  the  clothing,  while  in  the  severer 
cases  the  greatest  distress  is  occasioned  by  even  the  passage  of  a  feather 
over  the  surface.  This  disease  is  properly  classed  with  the  neuroses  of  the 
skin,  and  may  be  either  idiopathic  or  symptomatic  in  its  origin,  but  little 
is  known  of  its  etiology  or  pathology. 

Conditions  similar  to  this  are  sometimes  manifested  in  teeth  which  give 
no  other  evidence  of  disease  ;  teeth  in  which  the  integrity  of  the  enamel 
has  not  been  broken  ;  but  it  is  an  open  question  whether  the  sensation  of 
pain  is  primarily  due  to  an  exalted  sensibility  or  hypersesthesia  of  the  den- 
tinal fibrillse,  and  located  in  them  alone  or  in  the  pulp,  the  susceptibility 
of  which  has  been  abnormally  increased  to  all  forms  of  external  irritation. 

Although  the  exact  anatomic  and  histologic  character  of  the  dentinal 
fibrillse  have  never  been  i)ositively  demonstrated,  yet  there  is  no  good 
reason  for  doubting  that  they  are  terminal  nerve-fibres,  for  they  seem  in 
many  respects  to  possess  in  a  high  degree  the  functions  of  nerve-tissue. 
It  is,  therefore,  not  a  severe  strain  upon  the  imagination  to  suppose  the 
dentinal  fibrillse  capable  of  assuming  an  excessive  sensibility  or  hyperses- 
thetic  condition  as  an  expression  of  the  neurasthenic  state  of  the  patient, 
or  that  such  expression  may  be  primarily  manifested  in  the  pulp  itself, 
which  becomes  abnormally  sensitive  to  external  impressions  that  under 
other  conditions  would  cause  no  pain  or  uneasiness  whatever. 

In  those  cases  in  which  loss  of  substance  has  occurred  in  the  crown  of 
the  tooth  from  caries  or  traumatism  sufficient  to  expose  the  dentin,  it 
would  seem  that  the  hypersesthesia  begins  in  the  dentinal  fibrillae  and  ex- 
tends through  them  to  the  pulp.  This  view  receives  sui)port  from  the  fact 
that  if  these  cases  are  treated  with  silver  nitrate  applied  to  the  exposed 
dentin,  the  hypersesthesia  rapidly  disappears  and  the  tooth  regains  its 
normal  sensitivity. 

General  plethoric  conditions  of  the  system  and  pregnancy  are  often  pro- 
ductive of  hypersemic  states  of  the  dental  pulp,  by  reason  of  the  increased 
arterial  pressure  which  accompanies  these  conditions.  Some  of  the  most 
obscure  cases  of  odontalgia  that  the  writer  has  ever  had  to  deal  with  have 
been  finally  traced  to  one  or  the  other  of  these  conditions. 

Plethora  may  be  defined  as  a  condition  in  which  the  volume  of  the  blood 
in  the  body  is  in  excess  of  the  normal  amount  (polywmia),  and  in  which 
the  vessels  of  the  body  generally,  or  of  any  part,  are  over-distended  with 
blood.  It  is  made  manifest  in  flushing  of  the  face,  a  sense  of  fulness  in 
the  head,  buzzing  in  the  ears,  and  full  pulse,  caused  by  the  increased 
arterial  tension  and  fulness  or  engorgement,  particularly  of  the  capillary 
system  of  blood-vessels. 

Plethora  is  more  common  in  men  than  in  women,  and  is  most  frequently 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP.  387 

seen  in  middle  life.  It  has  been  stated  by  Jacobi  that  plethoric  conditions 
are  present  in  women  just  before  the  menstrual  periods. 

Osier  is  of  the  opinion  that  the  conditions  which  are  denominated 
plethora  are  the  result  not  of  an  actual  increase  in  the  volume  of  the 
blood,  but  rather  to  its  distribution  and  certain  local  peculiarities  of  the 
vessels  or  of  their  innervation. 

Individuals  of  this  dyscrasia  are  prone  to  capillary  hyperseraia ;  to 
rupture  of  the  arterioles  and  capillary  vessels  and  extravasations  of  the 
blood,  by  reason  of  the  continued  increased  blood-pressure,  and  the  con- 
sequent weakening  of  the  walls  of  the  vessels.  This  is  illustrated  by  the 
fact  that  this  affection  furnishes  a  fair  proportion  of  the  otherwise  healthy 
individuals  who  suffer  from  a  general  distention  of  the  superficial  vessels, 
hypersemia,  and  hemorrhagic  conditions  of  the  mucous  membrane  of  the 
upper  air- passages,  as  well  as  that  more  serious  and  often  fatal  aifection 
known  as  cerebral  apoplexy. 

The  tendency  in  plethoric  individuals  to  general  distention  of  the  super- 
ficial blood-vessels  and  engorgement  of  the  capillaries  the  writer  believes 
sometimes  results  in  hyperaemia  of  the  j)ulp  in  perfectly  sound  teeth, 
accompanied  by  pulsating  sensations,  a  sense  of  fulness  or  throbbing  pain 
which  may  be  referred  to  one  or  more  teeth.  In  other  cases  it  may  result 
in  rupture  of  the  vessels,  extravasation  of  blood,  inflammation,  and  death 
of  the  pulp. 

The  diagnosis  of  hypersemia  of  the  pulp  caused  by  plethora  is  quite 
readily  made  from  the  general  condition  of  the  patient,  the  absence  of  any 
discoverable  external  cause  of  irritation,  and  the  previous  history  of  the 
case,  which  is  invariably  a  sense  of  fulness,  accompanied  with  occasional 
pulsating  or  throbbing  sensations  in  the  tooth,  which  are  augmented  by 
vigorous  exercise  or  the  recumbent  position  ;  later  the  pulsating  or  throb- 
bing sensations  become  painful,  which  indicates  the  establishment  of  the 
hypersemic  state. 

Treatment  consists  in  reducing  general  and  local  arterial  tension.  This 
may  be  accomplished  in  the  first  instance  through  a  general  depletion  of 
the  system  by  the  administration  of  saline  cathartics,  a  restricted  diet,  and 
regular  exercise.  Local  arterial  tension  may  be  relieved  by  the  hot  foot- 
bath, keeping  the  extremities  warm,  the  bowels  open,  and  the  skin  free. 
If  general  treatment  fails  to  give  the  desired  relief  and  the  pain  continues, 
the  only  recourse  is  the  devitalization  and  extirpation  of  the  pulp. 

Pregnancy. — Pregnancy,  although  a  physiologic  process,  is  often  pro- 
ductive of  various  disordered  states  of  the  system.  It  will  be  sufficient  in 
this  connection,  however,  to  dwell  simply  upon  those  abnormal  conditions 
of  the  oral  cavity  which  are  referable  in  a  greater  or  less  extent  to  the 
usual  augmentation  in  the  volume  of  the  blood  during  this  period,  and  to 
a  plethoric  state  of  the  upper  half  of  the  body,  which  is  not  an  infrequent 
accompaniment,  and  to  those  nervous  phenomena  which  are  productive  at 
this  period,  of  neuralgic  conditions  of  the  trifacial  nerve. 

Changes  both  quantitative  and  qualitative  occur  in  the  blood  during 
pregnancy.  The  quantitative  change  in  the  blood  is  proved  by  the  in- 
creased area  of  the  circulation  brought  about  by  the  enlargement  of  the 


388  OPERATIVE    DENTISTRY. 

uterus  and  by  the  fulness  of  the  vessels,  a  fulness  which  is  sometimes  pro- 
ductive of  varicose  veins  or  of  serous  effusion.  This  increase  in  tlie 
volume  of  the  blood  was  first  demonstrated  by  Spiegelberg  and  Gescheidlen  * 
in  experiments  upon  pregnant  bitches. 

Authorities,  however,  are  not  agreed  as  to  the  qualitative  changes 
which  take  place  in  the  blood.  Andral, f  Nasse,  X  Meyer,  §  and  others  claim 
that  the  watery  elements  and  the  white  corpuscles  are  increased  and  the 
red  corpuscles  diminished.  lugerslev  ||  was  unable  to  detect  any  diminu- 
tion in  the  number  of  red  corpuscles,  while,  upon  the  other  hand,  Fehling  •[[ 
found  the  haemaglobin  and  the  red  corpuscles  increased. 

Temporary  hypertrophy  of  the  left  ventricle  sometimes  occurs  as  a 
result  of  increased  labor  thrown  upon  the  heart  as  a  consequence  of  the 
augmentation  of  the  blood  mass.  This  was  first  made  known  by  Larcher  ** 
in  1828. 

Venous  congestion,  varices,  and  swelling  of  the  lower  extremities,  and 
arterial  hyperemia  of  the  upper  half  of  the  body,  are  a  frequent  accom- 
paniment of  pregnancy.  The  causes  of  these  conditions  are  not  fully 
understood,  but  they  were  attributed  by  Christoforis  ff  to  pressure  of  the 
gravid  uterus  upon  the  iliac  veins,  which  prevented  the  normal  return  of 
the  blood  to  the  inferior  vena  cava,  and  to  pressure  upon  the  descending 
aorta,  thus  obstructing  a  normal  flow  of  blood  to  the  lower  extremities,  and 
causing  plethora  or  arterial  hypersemia  of  the  upper  portion  of  the  body. 

An  increase  in  the  salivary  secretions  is  often  a  noticeable  symptom. 
Ptyalism  when  present  manifests  itself  early,  and  usually  disappears  spon- 
taneously between  the  third  and  fourth  months.  It  occasionally  i)ersists, 
however,  in  an  exaggerated  form  during  the  entire  period  of  gestation, 
and  even  for  several  weeks  thereafter,  while  the  amount  secreted  may  be 
so  great  as  to  endanger  the  life  of  the  j)atient.  The  qualitative  changes 
in  the  saliva  during  pregnancy  are  sometimes  quite  marked.  The  water 
is  increased,  while  the  organic  and  inorganic  elements  are  diminished. 
Schramm  rei)orted  one  case  in  which  the  pytalin  was  entirely  absent.  In 
those  cases  in  which  an  excessive  flow  of  saliva  is  manifest  the  buccal 
mucous  membrane  is  more  or  less  inflamed,  the  parotid,  submaxillary,  and 
sublingual  glands  are  swollen,  tender,  and  quite  painful  when  their  secre- 
tory functions  are  especially  excited.-  Fcetor  is  not  present,  and  the 
absence  of  this  symptom  distinguishes  it  from  mercurial  ptyalism. 

The  cause  of  this  disorder  is  generally  thought  to  be  due,  in  all  proba- 
bility, to  a  reflex  neurosis,  though  the  writer  is  inclined  to  the  opinion  that 
it  is  due  to  over-stimulation  of  the  glands  resulting  from  the  general  hyper- 


*  Hirst's  American  System  of  Obstetrics,  p.  353. 
t  Amiales  de  Chimie  et  de  Physique,  Juillet,  1842. 
X  Archives  of  Gyn.,  Bd.  ix.  S.  338. 

I  Untersuchungen  iiber  die  Veranderungen  des  Blutes  in  der  Schwangerschaft. 

II  Centralb.  f.  Gyn.,  1879,  p.  635. 

f  Archives  f.  Gyn.,  Bd.  xxviii.  Heft  3,  S.  454. 
**  Hirst's  American  System  of  Obstetrics,  p.  346. 
tt  Ibid. 


DISEASES    AND    INJURIES    OF    THE    DENTAL,    PULP.  389 

femic  condition  of  all  the  tissues  of  the  uj)per  portion  of  the  body 
during  this  period.  The  affection  frequently  reappears  in  successive 
pregnancies. 

Gingivitis  is  another  common  oral  symptom  in  pregnancy,  and  is  often 
present  when  there  is  no  indication  of  salivation.  These  cases  are  charac- 
terized by  redness  and  tumefaction  of  the  gums  and  a  tendency  to  bleed 
on  slight  pressure  or  friction,  while  the  secretions  of  the  mucous  glands 
are  often  decidedly  acid  in  reaction. 

Phagedenic  pericementitis  is  occasionally  an  accompaniment  of  preg- 
nancy, and  is  frequently  associated  with  rheumatic  affections,  diabetes 
mellitus,  and  albuminuria,  but  just  how  it  is  associated  in  relation  to 
cause  and  effect  with  the  kidney  aifections  is  not  i^ositively  known,  but 
the  writer  has  suggested '!"  that  "it  is  due  in  these  cases  to  the  accumula- 
tion of  effete  products  in  the  system,  possibly  of  uric  acid,  urea,  and  other 
waste  material." 

JSTeuralgic  affections  are  also  quite  common  during  j)regnancy,  and  most 
frequently  affect  the  face  and  head.  Odontalgia  is  a  not  infrequent  accom- 
paniment of  pregnancy  in  teeth  which,  so  far  as  external  conditions  are 
presented,  appear  to  be  x)erfectly  sound.  This  affection  is  due  to  hyi^er- 
semia  of  the  pulp  induced  by  the  augmentation  in  the  volume  of  the  blood, 
the  increased  arterial  pressure,  and  general  hypersemia  of  the  upj^er  por- 
tion of  the  body. 

The  proof  of  this  statement  is  in  the  fact  that  a  brisk  cathartic  will 
often  relieve  or  entirely  control  an  attack  of  odontalgia  when  due  to  these 
causes.  It  operates  in  a  general  way  by  depleting  the  circulation,  thus 
relieving  the  arterial  tension  and  hypersemia  ;  while  it  acts  locally  by  re- 
ducing the  blood-pressure  in  the  pulj),  and  restoring  for  the  time  being  a 
normal  circulation. 

On  the  other  hand,  anaemic  states  of  the  blood  are  prone  to  establish 
general  and  local  neuralgic  conditions.  Anstie  has  graphically  epitomized 
the  definition  of  neuralgia  as  "  the  cry  of  the  hungry  nerves  for  food. ^^  The 
trifacial  nerve  is  frequently  the  seat  of  neuralgia,  the  pain  often  being 
located  in  one  or  more  teeth.  Cases  are  on  record  in  which  tooth  after 
tooth  has  been  extracted  under  the  belief  that  hyperaemia  or  inflammatory 
conditions  were  present  in  the  pulp  of  such  teeth,  when  in  reality  the 
cause  of  the  atfection  was  a  general  one,  due  to  an  impoverished  condition 
of  the  blood,  which  in  many  cases  could  undoubtedly  have  been  relieved 
by  approi^riate  general  tonic  treatment. 

Eeflex  neuralgic  phenomena  in  the  teeth  are  occasionally  encountered  as 
a  result  of  diseased  conditions  of  remote  organs,  or  of  hyj)erplastic  or  hj^per- 
trophic  enlargement  of  j)ortions  of  tissue  or  organs,  or  of  new  growths, 
which  cause  i^ressure  upon  important  nerve-trunks,  or  upon  the  nerves 
directly  supplying  the  teeth.  Consequently  in  the  diagnosis  of  all  obscure 
cases  of  odontalgia  due  weight  should  be  given  to  the  possibility  of  the 
affection  having  its  origin  in  some  one  of  these  remote  causes. 

*  Paper  on  "The  Teeth  of  Pregnant  Women,"  Transactions  of  the  American  Med- 
ical Association,  1889. 


390 


OPERATIVE    DENTISTRY. 


Fig.  486. 


NEW   FORMATIONS. 

Calcic  Formations  within  the  Pulp-Chamber. — The  formation  of 
secondary  growths  of  dental   tissue  within  the  pulp-chamber  and  calcic 
degenerations  of  the  tissues  of  the  pulp  have  never 
been  satisfactorily  classified. 

Salter  was  the  first  to  attempt  to  classify  the  vari- 
ous forms  of  new  growths  within  the  pulp-chamber, 
and  for  many  years  it  was  the  only  classification  used. 
Black  has  since  made  a  more  minute  and  comprehen- 
sive classification,  but  this,  he  thinks,  is  still  far  from 
complete  or  satisfactory. 

Salter  divides  secondary  growths  of  dentin  into 
three  different  forms, — viz.,  dent  in  of  t^epair,  dentin  ex- 
crescence, intrinsic  calcification,  or  osteodentin.  The  accom- 
panying illustration  (Fig.  486),  borrowed  from  Salter,* 
represents  these  forms  of  secondary  growths  in  the 
pulp-chamber  :  a  represents  a  mass  of  dentin  of  repair 
formed  to  compensate  for  the  wear  at  the  summit  of 
the  cusp  ;  5,  an  excrescence  or  tumor  projecting  from 
the  side  of  the  cavity  into  the  pulp  ;  c,  represented 
by  the  dark  cylinder  in  the  axis  of  the  pulp,  indicates 
where  the  formation  of  osteodentin  or  intrinsic  calci- 
fication begins. 

Dr.  Black  f  classified  the  secondary  deposits  within 
the  pulp-chamber  under  six  different  forms, — viz.  : 
*'!.  Secondary  Dentin. — A  new  growth  of  dentin  more  or  less  regular 
in  formation,  excited  by  abrasion,  decay,   or  other  injury,  by  which  the 
dentinal  fibrils  are  subjected  to  irritation  at  their  distal  ends. 

"2.  Dentinal  Tumors  within  the  Fulj)- Chamber. — ^An  erratic  growth  of 
dentin  into  the  pulp -chamber  united  to  the  wall  by  a  pedicle.  The  structure 
is  very  irregular. 

^'3.  Nodular  Calcifications  among,  hut  not  of,  the  Tissues  of  the  Didj). — 
These  are  the  irregular  nodulated  masses  so  frequently  seen  either  as  very 
small  stones  or  irregular  masses.     They  contain  many  calcospherites. 

''4.  Interstitial  Calcifications  of  the  Tissues  of  the  Pit/^9.— These  are  the 
counterpart  of  calcifications  elsewhere  in  the  body,  as  in  the  arteries,  etc. 

"5.  Cylindrical  Calcifications  of  the  Pidp. — The  tissues  in  this  form  ai'e 
probably  in  a  state  of  fibrous  degeneration,  which  is  usually  seen  in  the 
pulp- canals. 

^'6.  Osteodentin. — Erratic  formations  showing  both  the  lacunte  of  bone 
and  the  dentinal  tubes." 

Calcospherites  were  seen  by  Black  in  connection  with  many  of  these 
forms.  Other  irregular  formations  are  found  that  are  scarcely  assignable, 
he  thinks,  to  any  of  these  varieties,  and  it  is  not  unusual  to  find  the  vari- 
ous forms  intermixed  with  each  other. 


*  Dental  Pathology  and  Surgery. 


t  American  System  of  Dentistry 


Pulp-chamber 


indarr  deritic 


Fig.  487.— Secondary  dentin  on  wall  of  pulp-chamber.     (V.  A.  Latham.)     X  100. 


Secondary 
dentin 


--:%."  .'^^'^l 


Pulp-chamber 


ff-:. 

f. 

''•uj    .Ki.<-.     I 


Fig.  488.— Secondary  dentin  on  wall  of  pulp-chamber.     (V.  A.  Latham.)     "  •  9fl. 


Pulp-chamber 


Pulp-chamber 


Pulp-chamber 


Secondary  dentin 


Fig.  489.— Secondary  dentin  in  base  of  pulp-chamber.     (V.  A.  Latham.)     x  50. 


Pulp-nodule 


■1^- 


Dental  pulp 


Fig.  491.— Section  of  dental  pulp  containing  a  pulp-nodule.     (V.  A.  Latham.)     x  23. 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP.  391 

Secondary  dentin,  or  dentin  of  repair,  may  be  distinguished  from  tlie 
other  forms  of  secondary  deposit  by  the  fact  that  it  is  always  located  oppo- 
site some  lesion  of  the  external  tissues  of  the  tooth,  whereby  a  loss  of 
continuity  has  occurred  ;  that  it  is  adherent  to  and  in  direct  structural  con- 
tinuity with  the  primary  dentin  ;  that  the  pulp  is  not  attached  to,  nor  is  its 
structure  involved  in,  the  newly  formed  mass,  but  may  be  easily  removed. 

This  process  may  be  regarded  as  physiologic,  having  a  similar  signifi- 
cance to  the  process  of  repair  exhibited  in  bone-tissue. 

For  further  discussion  of  this  subject,  see  chapter  on  "Conservative 
Treatment  of  the  Pulp." 

Dentinal  Tumors. — These  are  rare  forms  of  secondary  growths  within 
the  pulp-chamber.  They  are  composed  of  calcific  material  of  notably  irreg- 
ular structure,  formed  in  masses  of  varying  size,  and  attached  by  a  pedicle 
to  the  primary  dentin,  or  occasionally  to  masses  of  secondary  formation. 
They  are  confined  entirely  to  the  pulp-chamber.  The  dentinal  tubes 
within  the  mass  are  continuous  with  the  tubules  of  the  primary  dentin 
(Fig.  487). 

Dr.  Black  is  of  the  opinion  that  they  are  the  result  of  the  same  causes 
as  those  leading  to  the  formation  of  secondary  dentin  generally.  With 
this  opinion  the  writer  cannot  fully  agree,  for  the  reason  that  such  growths 
have  been  occasionally  found  in  teeth  in  which  there  were  no  evidences  of 
any  external  cause  of  irritation.  Of  the  circumstances  which  determine 
the  erratic  tumor-like  form  of  the  growth  nothing  whatever  is  definitely 
known.  Figs.  488  and  489  show  two  very  erratic  forms.  Wedl  and  Heider 
believe  it  is  due  to  an  inversion  of  the  layer  of  dentinal  cells,  and  that  the 
space  formed  within  the  surface  of  the  pulp  by  the  inversion  is  later 
occupied  by  new  dentin.  They  say,  ' '  These  formations  are  by  no  means  of 
rare  occurrence,  and  that  they  are  found  attached  to  the  original  dentin 
by  means  of  a  pedicle,  and  in  cases  where  there  is  no  con- 
nection  with  a  pedicle  detachment  has  ensued."  ^^' 

Nodular  Calcifications,  or  Pulp-Stones. — These  are 
found  in  globular  masses  (Fig.  490)  and  spindle-shaped 
masses  scattered  through  the  substance  of  the  pulp,  par- 
ticularly in  the  teeth  of  adults.  They  may  be  found  in 
any  part  of  the  pulp-tissue,  but  most  often  in  the  coronal 
portion.  In  form  they  are  irregularly  nodulated,  appear- 
ing to  be  made  up  of  an  aggregation  of  smaller  nodules. 
In  structure  they  appear  to  be  masses  of  calcific  material 
composed  of  the  same  elements  as  dentin,  but  lacking  its 
peculiar  structure.  Embedded  within  the  calcific  material 
are  numerous  bodies  made  up  of  concentric  rings,  which  are  calcosphe- 
rites.  Various  irregular  lines  are  seen  running  through  the  mass,  which 
may  be  tubules  or  only  faults  in  the  structure. 

The  formation  of  pulp-nodules  is  thought  to  be  due  to  the  deposition 
of  masses  of  calcoglobulin  within  the  pulp,  and  which  is  known  to  form 
the  base  of  the  pulp-nodule, — the  calcospherite,  enamel,  dentin,  and  bone, 
— the  lime-salts  entering  into  combination  with  the  calcoglobulin  to  form 
calcospherites,  and  these  uniting  in  larger  masses  form  the  pulp-nodules. 


392  OPERATIVE    DENTISTRY. 

Wedl,  Salter,  Black,  and  other  writers  look  upon  their  presence  in  the 
tissues  of  the  pulp  as  a  result  of  some  form  of  peripheral  irritation  of  the 
dentinal  fibres,  as  they  are  found  in  increasing  numbers  in  the  teeth  of 
those  who  have  suffered  from  caries,  abrasion,  erosion,  inflammatory  con- 
ditions of  the  pericementum,  or  other  injury  or  disease.  Figs.  491  and  492, 
which  show  a  pulp-nodule  m  situ,  are  made  from  a  pulp  removed  from  a 
tooth  which  was  the  subject  of  pyorrhoea  alveolaris.  Tomes  does  not  quite 
a"-ree  with  this  view,  as  he  found  globular  masses  in  three  out  of  five  speci- 
mens of  perfectly  sound  molar  teeth  removed  post  mortem  from  subjects 
in  the  hospital  morgue.  Eobin  and  Magitot  called  attention  to  the  pres- 
ence of  isolated  calcareous  granules  of  globular  form  which  were  scattered 
through  the  substance  of  the  pulp  in  the  early  stages  of  dentin  formation. 
Henle  and  others  have  likewise  described  them  as  present  in  the  teeth  of 
man,  ruminants,  and  rodents.  C.  S.  Tomes  found  them  in  the  developing 
teeth  of  ruminants,,  scattered  freely  through  the  dentinal  pulp,  and  finally 
becoming  embedded  at  various  depths  within  the  substance  of  the  dentin. 

The  fact,  therefore,  remains  that  many  cases  of  calcific  nodular  forma- 
tions within  the  pulp  have  their  origin  in  other  than  external  causes  of 
irritation.  Black  looks  upon  the  presence  of  a  few  pulp-nodules  in  the 
tooth  as  of  no  special  pathologic  significance  as  far  as  the  future  health  of 
the  tooth  is  concerned. 

Calcification  of  the  Tissues  of  the  Pulp. — This  is  a  condition  often 
seen  in  the  teeth  of  elderly  persons,  as  the  result  of  senile  change  or  de- 
generation of  tissue.  Fibroid  degeneration  (Fig.  493)  is  one  of  the  most 
common  precedents  of  calcareous  deposits  in  the  pulp. 

Calcareous  deposits  formed  within  the  structure  of  the  tissues,  according 
to  Ziegler,  usually  occur  in  localities  where  the  tissues  have  already  lost 
their  vitality  or  are  in  a  process  of  degeneration  or  necrobiosis.  It  appears 
as  if  dying  tissue  which  has  undergone  more  or  less  modification  possesses 
a  kind  of  attraction  for  the  lime-salts  which  are  in  solution  within  the 
body,  and  enters  into  intimate  combination  with  them.  The  tissues  which 
are  most  prone  to  calcareous  degeneration  are  connective  tissue  which  has 
undergone  hyaline  degeneration  or  sclerosis,  the  walls  of  blood-vessels, 
tumors,  and  other  portions  of  the  body  which  are  undergoing  hyaline  or 
fatty  degeneration,  degenerating  cartilage,  dead  cell-bodies,  and  cheesy 
areas  of  considerable  size. 

Tissue-calcification  is  uniformly  associated  with  degenerative  changes 
in  the  structures  of  the  pulp.  Calcification  may  affect  small  or  large  areas, 
causing  in  the  latter  case  a  distinct  hardening  of  the  tissue  and  a  whitish 
coloration. 

The  process  is  characterized  by  the  formation  of  numerous  minute 
islands  of  calcification  scattered  through  the  tissue  of  the  pulp,  of  regular 
outline,  and  presenting  a  smooth  surface. 

There  is  considerable  difference  in  the  microscopic  appearance  of  these 
islands  of  calcification.  In  some  of  them  are  seen  on  section  the  calcified 
tissue  elements  of  the  pulp,  others  appear  to  be  of  granular  structure,  with 
a  few  irregular  and  wavy  tubes  scattered  through  them,  and  still  others 
appear  to  have  no  structure  at  all. 


Pulp-nodule 


Fig.  492. — Vertical  section  of  dental  pulp,  showing^  puli>nodule.     (V.  A.  Latham.) 


■it, 


Fig.  4'.'3.— Section  of  tooth-jiulp  undergoing  fibroid  degeneration.     (V.  A.  Latham.)     >'  UO. 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP. 


393 


Salter  aud  Black  both  describe  a  peculiar  form  of  degenerative  calcifi- 
cation occurring  in  tlie  radial  portion  of  the  pulps  of  teeth,  particularly  in 
the  roots  of  the  molars,  which  they  have  termed  cylindrical  calcification. 


Fig.  494. 


Cylindrical  calcification  of  the  pulp,  early  stage.     (After  Dr.  Black.) 


From  the  apj)earances  exhibited  in  sections  of  cylindrical  calcification, 
it  is  evident  that  it  is  a  calcareous  degeneration  of  a  previous  fibrous 
degeneration  of  the  pulp.  This  is  shown  in  the  accompanying  illustrations 
by  Dr.  Black.     Pig.  494  shows  an  early  stage  of  the  degenerative  process  ; 

Fig.  495. 


Cylindrical  calcification  of  the  pulp,  early  stage  ;  nodules  teased  apart.     (After  Dr.  Black.) 

Fig.  495  is  a  similar  section  in  which  the  nodules  have  been  spread  out  to 
show  the  attachment  of  the  cylindrical  masses  to  the  fibrous  elements  of  the 
pulp  ;  while  Fig.  496  shows  a  more  advanced  stage  of  the  disease  in  which 
the  cylinders  run  together  and  join  end  to  end,  forming  jointed  rods,  but 
do  not  coalesce.  In  this  stage  of  the  disease  the  radial  portion  of  the  pulp 
becomes  stiffened  and  may  be  bent  at  various  angles,  and  will  retain  its 
bent  position.  Salter  says— and  Black  agrees  with  him— that  ultimately 
"the  whole  of  the  tissues,  cells,  nuclei,  connective  tissue,  blood-vessels, 
and  multitudes  of  neri^es  are  swallowed  up  and  obliterated  in  the  calcific 


394 


OPERATIVE    DENTISTRY. 


process.  The  process  of  calcification  is  clearly  not  interstitial  in  the  sense 
of  being  between  the  fibres."  This  variety  of  calcification  is  usually  asso- 
ciated with  other  forms,  and  there  is  generally  more  or  less  calcification  of 
the  coronal  portion  of  the  pulp,  either  in  the  form  of  secondary  dentin  or 

Fig.  496. 


Cylindrical  calcification  of  the  pulp,  advanced  stage.     (After  Dr.  Black.) 

interstitial  calcification.     Figs.  497  and  498  illustrate  such  a  condition,  the 
coronal  portion  of  the  pulp  being  completely  calcified. 

Osteodentin  is  a  secondary  formation  of  rare  occurrence  in  the  humaji 
teeth,  but  it  is  common  in  the  teeth  of  animals,  particularly  in  very  large 


Fig.  497. 


Fig.  498. 


animals,  like  the  elephant.  These  formations  are  the  result  of  long- con- 
tinued or  chronic  irritation.  As  its  name  implies,  it  is  a  form  of  secondary 
growths  which  combine  the  elements  of  both  dentin  and  bone,  or,  more 
correctly,  of  cementum  (Fig.  499).  It  is  develoj)ed,  according  to  Salter, 
by  the  general  conversion  and  intrinsic  calcification  of  the  several  tissues 
of  the  pulp.  It  is  usually  vascular,  frequently  arranged  in  systems  around 
vessels,  like  the  Haversian  systems  of  bone,  and  it  sometimes  has  true 
lacuuse.  It  has  fewer  dentinal  tubules  than  any  other  form  of  dentin,  and 
is  usuallj"  very  transparent.  It  is  made  up  of  various  calcification  islands 
or  systems  of  secondary  dentin,  which  are  finally  fused  together  and  ad- 
herent to  the  primary  dentin  (Fig.  500).  The  mass  may  contain  any 
number  of  Haversian  systems  and  numerous  true  bone  lacunae,  especially 
resembling  those  found  in  the  cementum. 

These  masses  of  osteodentin  are  found  in  teeth  which  show  marked 


DISEASES    AND    INJURIES    OF    THE    DENTAL    PULP, 


395 


evidences  of  a  former  resorption  of  dentin,  and  although  in  many  cases 
the  tissues  increased  in  amount,  a  considerable  portion  was  found  to  occupy 

Fig.  499. 


Section  of  osteodentin.    (After  Salter. ) 

the  situation  of  the  normal  dentin  which  had  been  removed  by  the  pro- 
cess of  resorption. 

Bodecker^^  has  also  described  this  form  of  new  growth  as  secondary 
dentin  with  forms  analogous  to  Haversian  systems. 

Fig.  500. 


Section  of  obteodcutiu.     (.Alter  female  and  Colyer.) 


Occasionally  the  resorbed  dentin  will  be  replaced  by  bone.  Fig.  501, 
which  is  taken  from  the  '' Transactions  of  the  Odontological  Society  of 
Great  Britain,"  1893,  shows  a  section  made  from  a  partially  erupted  tooth, 


*  Dental  Cosmos,  1879. 


396 


OPERATIVE    DENTISTRY. 


the  root  of  which  had  apparently  been  about  two-thirds  formed,  and  ap- 
peared as  though  it  had  been  fractured,  but  upon  microscopic  examination 
it  was  found  that  this  appearance  was  due  to  resorj)tiou.  The  bone-tissue 
occupies  the  cavity  formed  by  the  process  of  resorption. 


Fig.  501. 


Section  of  dentin  showing  resorption  area  occupied  by  bone-tissue.     (After  Smale  and  Colyer. ) 

Irritation  and  hyperemia  of  the  pulj),  it  will  be  seen  from  the  fore- 
going descriptions,  could  hardly  occur  from  any  of  the  various  forms  of 
secondary  deposits  except  those  mentioned  under  the  head  of  internal 
local  causes, — viz.,  dentinal  tumors  and  pulp-stones, — by  reason  of  the  fact 
that  all  the  other  forms  of  secondary  deposits  are  conversions  of  tissue, 
while  these  are  erratic  growths,  occupying  space  in  the  x^ulp-chamber  or 
in  the  tissue  of  the  pulp,  where  they  produce  pressure  upon  the  nerve- 
filaments,  causing  irritation. 


CHAPTEE   XXIV. 

INFLAMMATION  OF  THE  DENTAL  PULP. 

Definition. — Inflammation  (Latin,  inflammatio,  from  inflammare,  to  in- 
flame ;  injiammo,  I  set  on  fire),  is  a  condition  of  nutritive  disturbance,  char- 
acterized by  hypersemia,  with  proliferation  of  the  cells  of  a  tissue  or  organ, 
and  attended  by  one  or  more  of  the  symptoms  of  pain,  heat,  swelling,  dis- 
coloration, and  disordered  function.  Inflammation  is  a  series  of  changes  in 
a  part  identical  with  those  which  are  produced  in  the  same  part  by  injury 
from  a  chemic  or  a  physical  irritant. 

Pulpitis  is  the  term  applied  to  inflammation  of  the  dental  pulp.  (Latin, 
pulpa,  pulp,  and  itis,  a  suffix  used  to  indicate  inflammation.) 

Physical  Signs. — The  physical  signs  or  cardinal  symptoms  of  inflam- 
mation, as  described  by  Celsus,  are  four  in  number, — viz.,  rubor,  tumor, 
calor,  and  dolor,  redness,  swelling,  heat,  and  pain  ;  a  fifth  symptom  has 
since  been  added  to  complete  the  description  of  the  physical  phenomena 
as  presented  in  the  tissues, — viz.,  functio  loesa,  disturbance  of  function  in 
the  part. 

Inflammation  is  a  symptom  of  disturbed  function,  but  not  a  disease. 
It  is  an  effort  upon  the  part  of  the  system  to  eliminate  or  render  inert  or 
harmless  the  primary  cause  of  the  disturbance. 

All  forms  of  inflammation  are  the  result  of  the  action  of  certain  forms  of 
irritation.  Irritants  are  classed  under  four  general  heads, — viz.,  mechanic, 
chemic,  septic,  and  nervous. 

Mechanic  irritants  produce  irritation  through  their  mechanic  action. 
Examples  :  the  presence  of  foreign  bodies,  pressure  from  external  sources, 
pressure  from  new  growths,  traumatisms,  accidental  or  surgical,  etc. 

Chemic  irritants  are  substances  which  irritate  by  virtue  of  their  chemic 
reaction  upon  the  tissue  elements  with  which  they  come  in  contact.  Ex- 
amples :  alkalies,  acids,  and  escharotics,  like  chromic  acid,  or  certain 
coagulants,  like  carbolic  acid  and  silver  nitrate,  or  violent  irritants,  like 
croton  oil  and  cantharides.  Other  examples  are  found  in  drugs  which 
through  their  constitutional  exhibition  produce  peculiar  effects  upon  cer- 
tain tissues  and  organs,  and  which  if  administered  in  toxic  doses  will  cause 
inflammation.  Mercury  acting  upon  the  tissues  of  the  mouth  and  salivary 
glands  produces  stomatitis  and  salivation.  Cantharides  will  cause  irrita- 
tion of  the  urinary  organs,  ergot  of  the  uterus,  and  uric  acid  will  produce 
gouty  inflammations.  The  toxic  inflammation  caused  by  the  poison  of 
serpents  and  certain  insects,  the  poisonous  action  of  certain  plants,  like 
the  Bhus  toxicodendron,  and  the  ptomaines  are  examples  of  still  other  groups 
of  chemic  irritants. 

Septic  irritaiits  are  living  organisms, — parasites  or  micro-organisms, — 
which  cause  irritation  by  their  presence  in  the  tissues  or  by  the  elabora- 

397 


398  OPERATIVE     DENTISTRY. 

tion  of  toxic  substances — ptomaines — as  waste  products  and  their  intro- 
duction into  the  system  by  absorption.  The  pus- microbes  and  the  sapro- 
phytic germs  belong  to  this  class. 

Nervous  irritants  are  those  which  produce  irritation  through  the  medium 
of  the  nervous  system  by  disturbing  the  normal  functions  of  the  part. 
The  influence  which  is  exerted  by  the  nervous  system  over  the  functions 
of  nutrition,  both  generally  and  locally,  in  the  production  of  inflammatory 
symptoms  has  long  been  recognized. 

Impairment  of  the  nutrition  of  the  skin  is  sometimes  observed  to  follow 
injury  of  the  nerves  supplying  the  part.  Degenerative  changes  have  been 
known  to  take  place  in  the  pulps  of  the  lower  teeth  following  exsection  of 
the  inferior  dental  nerve.  Eeflex  nervous  conditions  are  also  recognized  as 
being  productive  of  inflammatory  phenomena.  An  instance  in  point  is 
the  nervous  irritation  sometimes  caused  in  the  dental  pulp  by  a  misplaced 
uterus  or  the  condition  of  pregnancy.  Herj)es  zoster  is  an  example  of  a 
pustular  eruption  following  the  course  of  a  nerve,  the  inflammation  being 
accompanied  with  infiltration  of  leucocytes  around  both  the  terminal 
branches  and  the  trunk  of  the  nerve. 

Inflammation  is  a  process  which  may  affect  any  tissue  of  the  body 
having  a  vascular  circulation  or  which  is  connected  with  blood-vessels. 
Enamel  which  has  no  vascular  circulation  and  is  in  no  way  connected 
with  blood-vessels  cannot  be  the  seat  of  inflammation.  Dentin,  which 
occupies  a  position  midway  between  enamel  and  bone  in  the  evolution  of 
the  calcareous  tissues,  presents  conditions  which  are  thought  by  certain 
authorities — Heitzmann,  Abbot,  Bodecker,  and  others — to  be  inflammatory 
in  their  nature,  the  peculiarities  of  the  symptoms  being  due  to  the  low 
state  of  vitality  and  the  small  percentage  of  organic  matter  contained  in 
its  structure. 

Inflammation  in  vascular  tissues  usually  begins  with  the  phenomena  of 
hypersBmia,  and  progresses  to  exudation  or  to  suppuration ;  sometimes  reso- 
lution takes  place,  at  others  leading  to  the  production  of  new  formations, 
or  to  metamorphoses  of  various  kinds,  or  to  devitalization  and  destruction 
of  tissue,  and  creating  a  more  or  less  serious  disturbance  of  the  functions 
of  the  parts.  The  inflammatory  process  may  vary  greatly  in  its  character 
and  in  its  location. 

The  histologic  character  of  inflammations  depends  upon  two  factors, — 
the  nature  of  the  exudation  and  the  changes  in  the  tissues.  Both  are  used  to 
classify  the  various  forms  of  inflammation,  according  as  the  one  or  the 
other  seems  to  be  most  pronounced. 

Exudation. — Exudation  or  diapedesis  is  the  process  by  which  during 
partial  stasis  of  the  blood-current  the  corpuscular  elements  of  the  blood 
(the  leucocytes  and  phagocytes)  and  the  liquor  sanguinis  pass  through  the 
walls  of  the  blood-vessels  into  the  tissue  spaces  beyond.  This  process  is 
the  result  of  changes  in  the  vessel  walls,  which  permit  the  passage  or 
leakage  of  the  elements  of  the  circulating  fluid  through  the  walls  of  the 
vessels.  Ziegler  says,  ' '  It  may  be  accepted  as  an  established  fact  that  in 
inflammation  the  vessel  wall  is  affected,  but  it  is  still  questioned  by  some 
whether  the  affection  is  of  the  nature  of  a  chemic  alteration  or  a  mere 


INFLAMMATION    OF    THE    DENTAL    PULP.  399 

widening  of  pre-existing  intercellular  spaces."  Bnrdon  Sanderson  believes 
' '  it  is  due  to  the  loss  of  the  power  by  the  vessels  of  resistance  to  dilatation, 
and  the  loss  of  vital  power,  in  consequence  of  which  leakage  takes  place." 
Rupture  or  rhexis  of  the  vessel  walls  sometimes  takes  place,  which  permits 
the  red  blood-corpuscles  to  escape  into  the  tissues. 

Tissue  Changes. — The  cellular  and  fluid  exudates  which  pass  through 
the  vessel  walls  collect  first  in  their  immediate  neighborhood,  but  rapidly 
spread  out  and  involve  surrounding  healthy  tissue  by  occupying  the 
lymph-spaces  of  the  tissues.  When  this  tissue  infiltration  is  considerable 
it  is  liable  to  produce  other  disturbances  of  circulation  and  nutrition, 
and  thus  increase  the  area  of  the  inflammatory  exudation  and  tissue 
degeneration. 

Among  the  earliest  changes  which  take  place  in  the  inflamed  tissue  is 
the  coagulation  of  the  fibrinous  elements  of  the  exudate,  which  prevents, 
the  further  movement  of  the  migrated  corpuscles  by  enclosing  them  in  the^ 
coagulated  mass. 

One  of  the  functions  of  the  leucocytes  is  to  take  up  solid  particles  and 
portions  of  broken  down  and  disintegrated  blood-corpuscles.  Metchnikoff 
(1884)  and  his  followers  claim  that  they  have  also  the  power  of  englobing 
and  destroying  the  invading  pathogenic  bacteria  which  have  gained  an 
entrance  to  the  blood  and  other  tissues  of  the  body.  And  that  by  this 
phagocytic  power  of  the  leucocytes  immunity  was  established  in  the 
organism.  He  found  in  certain  observations  made  ujDon  a  species  of 
daphnia,  which  is  subject  to  infection  by  a  torula  resembling  the  yeast 
fungus  that  gains  access  to  its  body  through  its  food,  that  the  fungus 
penetrates  the  walls  of  the  intestines  and  invades  the  tissues.  In  certain 
cases  the  infection  was  not  fatal,  and  this  he  believed  was  due  to  the  fact 
that  the  leucocytes  which  accumulated  around  the  invading  fungi  seized 
upon  these  organisms,  and  eventually  destroyed  them.  If  the  leucocytes, 
were  successful  in  overpowering  the  i:)arasites,  the  animal  recovered ;  if 
not,  the  infection  proved  fatal.  From  this  he  argued  that  the  pathogenic 
bacteria,  when  introduced  into  the  body  of  an  immune  animal,  are  de- 
stroyed in  a  like  manner,  while  they  play  an  active  part  as  prophylactic 
agents  and  in  the  metamorphosis  of  tissues  and  organs  in  inflammation. 

Metchnikoff  explained  that  the  leucocytes  gathered  up  the  bacilli  and 
destroyed  them  by  a  process  of  internal  digestion.  This  power  of  the 
leucocytes  to  destroy  foreign  substances  was  first  suggested  by  Surgeon- 
General  Sternbergh,  of  the  United  States  army,  in  1881. 

•  There  is  still  a  difference  of  opinion  as  to  the  power  of  the  leucocytes 
to  destroy  living  bacteria.  Koch  found  in  1878  that  the  bacteria  multiplied 
within  the  body  of  the  leucocytes,  and  that  many  of  these  cells  were  de- 
stroyed by  the  bacteria. 

Sternbergh,  Weigert,  Baumgarten,  and  others,  have  maintained  that  the 
bacteria  found  in  the  leucocytes  were  already  dead  when  taken  up  by  these 
cells,  their  vitality  having  been  destroyed  by  some  agency  outside  of  the 
leucocytes,  namely  the  blood-serum,  and  that  there  is  abundant  experi- 
mental evidence  to  prove  that  the  blood-serum  has  decided  germicidal 
power. 


400  OPERATIVE   DENTISTRY. 

Sternbergh  says  (1892),  "Numerous  experiments  have  been  made  during 
the  past  two  or  three  years  with  the  view  of  determining  whether  x>atho- 
genic  bacteria  are,  in  fact,  destroyed  within  the  leucocytes  after  being 
picked  up  by  them,  and  different  experimenters  have  arrived  at  opposite 
conclusions.  In  the  case  of  mouse  septicaemia,  and  in  gonorrhoea,  one 
would  be  disposed  to  decide,  from  the  appearances  and  the  arrangement 
of  the  pathogenic  bacteria  in  the  leucocytes,  that  they  are  not  destroyed, 
but  that,  on  the  other  hand,  they  multiply  in  the  interior  of  these  cells, 
which  in  the  end  succumb  to  this  parasitic  invasion.  In  both  of  the 
diseases  mentioned  we  find  leucocytes  so  completely  filled  with  the  patho- 
gejiic  micro-organisms  that  it  is  difficult  to  believe  that  they  have  all  been 
picked  up  by  a  voracious  phagocyte  which  has  stuffed  itself  to  repletion, 
while  numerous  other  leucocytes  from  the  same  source  and  in  the  same 
microscopic  field  of  view  have  failed  to  capture  a  single  bacillus  or  micro- 
coccus. Moreover,  the  staining  of  the  x)arasitic  invaders  and  the  charac- 
teristic arrangement  of  the  gonococcus  in  stained  preparations  of  gonor- 
rhoeal  pus  indicate  that  their  vitality  has  not  been  destroyed  in  the  interior 
of  the  leucocytes  or  jDns-cells,  and  we  can  scarcely  doubt  that  the  large 
number  found  in  certain  cells  is  due  to  multiplication  in  situ  rather  than  to 
an  unusual  activity  of  these  peculiar  cells.  But  in  certain  infectious  dis- 
eases, and  especially  in  anthrax,  the  bacilli  included  within  the  leucocytes 
often  give  evidence  of  degenerative  changes,  which  would  support  the  view 
that  they  are  destroyed  by  the  leucocytes,  unless  these  changes  occurred 
before  they  were  picked  up,  as  maintained  by  JSTuttall  and  others." 

Nuttall  (1888)  has  shown  that  the  destruction  of  virulent  micro-organ- 
isms in  the  blood  of  animals  was  not  dependent  alone  upon  the  immediate 
presence  of  living  leucocytes,  but  that  the  serum  of  the  blood,  when  freed 
from  all  cellular  elements  of  any  kind,  still  possessed  the  power  of  de- 
stroying the  vitality  of  bacterial  forms  equal  to  that  of  the  blood  in  its 
normal  state  when  all  of  its  constituent  elements  were  present. 

Buchner  (1890)  demonstrated  that  the  serum  was  robbed  of  its  germi- 
cidal properties  by  exposure  to  a  temi)erature  of  55°  C.  for  half  an  hour. 
Its  efficiency,  on  the  other  hand,  was  not  impaired  by  alternately  freezing 
and  thawing  it,  but  dialysis  or  extreme  dilution  with  distilled  water  dimin- 
ished its  germicidal  power  or  completely  destroyed  it.  If,  however,  it  was 
diluted  with  an  equal  amount  of  water  containing  from  0.6  to  0.7  per  cent, 
of  sodium  chloride,  its  germicidal  action  was  in  no  way  diminished.  From 
this  he  concluded  that  the  active  agent  in  the  blood  which  gave  it  this 
germicidal  power  is  a  living  albumin,  and  that  an  essential  constituent' is 
sodium  chloride,  the  removal  of  which,  either  by  dialysis  or  dilution, 
robbed  the  blood  of  its  germicidal  power.  These  elements  or  constituents 
of  the  blood  which  possess  the  power  of  destroying  pathogenic  micro- 
organisms he  termed  "alexins." 

Hankin,  Martin,  and  Ogatta  (1891)  have  succeeded  in  isolating  ferment- 
like "globulins,"  which  in  solution  possess  active  germicidal  powers. 

Later,  Vaughn,  ^ovy,  and  McClintock  have  found  in  their  observations 
that  the  nucleins  are  the  most  important  germicidal  and  protective  agents 
possessed  by  the  body  ;  that  this  bacterial  constituent  of  the  blood-serum 


INFLAMMATION  OF  THE  DENTAL  PULP.  401 

is  not  a  serum  albumin,  but  that  it  is  a  proteid,  for  it  is  destroyed  at 
60°  C. ;  and  that  it  is  probably  a  nuclein,  for  it  is  not  destroyed  by  gastric 
digestion. 

The  nuclein  which  they  isolated  was  found  to  possess  most  powerful 
germicidal  properties  when  tested  upon  Koch's  comma  bacillus,  the  strepto- 
coccus ]^yogenes  aureus^  and  the  bacillus  anthracis. 

If  resolution  now  takes  place  the  blood- current  gradually  resumes  its 
natural  flow,  resorption  of  the  exudates  begins,  the  induration  and  swell- 
ing disappear,  the  pain  ceases,  and  the  tissues  regain  their  normal  color 
and  functions. 

If,  on  the  other  hand,  stasis  becomes  complete  in  a  limited  inflamed 
area,  suppuration  is  established,  first,  by  the  death  or  necrosis  of  the  exuded 
blood-cells  and  of  the  embryonal  and  fixed  tissue-cells, — necrobiosis, — and 
secondly,  by  the  liquefaction  and  complete  dissolution  of  the  tissue  ele- 
ments, the  leucocytes  and  embryonic  cells  formed  from  the  fixed  tissue-cells 
—phagocytes — being  converted  into  pus-corpuscles  and  the  intercellular 
substance  of  the  tissues  liquefied. 

Complete  stasis  occurring  in  larger  areas  may  result  in  death  of  tissue 
en  masse;  when  this  occurs  in  soft  tissues  it  is  termed  gangrene;  when 
occurring  in  bony  tissues  it  is  termed  necrosis. 

Another  change  which  may  take  place  in  the  inflammatory  exudates  is 
that  of  fatty  degeneration.  This  is  a  process  of  retrograde  change  by  which 
the  albuminoid  elements  of  the  tissues  and  the  exudates  are  converted  into 
granular  fatty  matter. 

Pus,  tubercles,  etc.,  are  sometimes  converted  into  soft,  cheese-like  masses 
by  a  degenerative  change  known  as  caseation. 

Hyperplasias,  or  Tiypertropliies  of  tissue,  are  not  uncommon  sequelae  of  in- 
flammation. Hyperplasia  is  an  increase  of  the  elements  which  compose  a 
tissue  or  an  organ,  resulting  in  an  increase  in  the  volume  of  the  tissue  or 
organ,  and  may  be  due  either  to  over-stimulation,  over-nutrition,  irrita- 
tion, or  a  low  form  of  inflammation.  Polypus  of  the  pulp,  enlargement 
of  an  irritated  gum  festoon,  and  hypercementosis  are  examples  of  this 
condition. 

New  formations  resulting  from  inflammations  are  due  to  a  proliferation 
of  embryonic  cells  and  their  organization  into  new  tissue,  sometimes  simi- 
lar in  kind,  but  often  of  a  different  character  from  the  tissue  in  which 
they  originate,  resulting  in  the  formation  of  tumors  of  various  kinds, 
some  benign,  others  malignant. 

Examples  of  the  former  variety  are  the  calcareous  formations  developed 
within  the  pulp-cavity ;  and  of  the  latter,  good  examples  of  the  benign 
tumors  are  found  in  the  fibromas  which  sometimes  occur  upon  the  gums, 
and  the  malignant  varieties  are  well  shown  in  osteosarcomas  of  the  jaws 
and  in  eiDitheliomas  of  the  lips. 

Inflammation  is  usually  divided  into  two  forms, — viz.,  acute  and  chronic, 
— and  these  again  into  many  varieties,  according  to  the  anatomical  location 
of  the  process,  as  taught  by  Virchow,  such  as  catarrhal,  fibrinous,  paren- 
chymatous, phlegmonous,  indurative,  degenerative,  scrofulous,  and  infec- 
tive. 

26 


402 


OPERATIVE    DENTISTRY. 


Ill  acute  inflammation  the  process  runs  a  more  or  less  rapid  course  and 
the  symptoms  are  marked,  while  in  the  chronic  form  the  symptoms  are  all 
less  prominent,  and  any  one  or  all  of  the  cardinal  symptoms  may  be  so 
slightly  developed  as  to  escape  notice  altogether.  A  form  between  these 
two  conditions  has  been  denominated  subacute  inflammation. 

TABLE   OF   INFLAMMATORY   PHENOMENA. 

Summary  of  steps  : 

.  Traumatic 


1.  Irritants. 


h.   Chemic. 

c.  Bartoric  or  septic. 

d.  Electric. 

e.  Thermic. 
Irritation. 

Determination  or  active  hyperaemia. 
Disturbance  of  circulation. 
Increased  motion  and  retardation  or  oscillation. 

6.  Stasis  (partial). 

7.  Vascular  dilatation. 

8.  Exudation, — diapedesis,  i-hexis. 

9.  Swelling, — cedema. 

a.  Eesolution,  or  absorption  or  organization. 

h.  Fibroid  thickening  or  chronic  inflamma- 
10.  Terminations.  -{  tion. 

c.  Suppuration. 

d.  Abscess, — necrosis. 

e.  Ulceration. 
./.  Gangrene. 


a.  Vascularization. 
h.   Granulation, 
c.   Scar-tissue. 
Hyperplasia. 
New  formations. 


INFLAMMATION   OF   THE   PULP. 

Etiology. — Inflammation  of  the  pulp  may  be  either  acute,  subacute, 
or  chronic  in  form,  and  each  of  these  varieties  may  involve  only  a  limited 
area  of  the  pulp,  when  it  is  termed  circumscribed  inflammation,  or  it  may 
involve  the  whole  of  the  organ,  when  it  is  termed  diffuse  or  general  inflam- 
mation. 

Acute  ^pulpitis  is  in  a  very  large  majority  of  cases  due  to  exposure  of  the 
pulp,  either  from  caries,  fracture  of  the  crown,  mechanical  abrasion,  or 
erosion.  About  ninety-six  per  cent,  of  the  primary  cases,  according  to 
the  records  of  the  writer,  are  due  to  exposure  from  caries  ;  about  three  per 
cent,  to  fractures,  abrasions,  erosions,  and  other  injuries  of  a  traumatic 
nature  involving  a  loss  of  tissue  ;  and  one  per  cent,  to  constitutional  con- 
ditions, such  as  plethora,  pregnancy,  nervous  irritability,  and  kindred 
affections. 

These  figures  accord  very  closely  with  those  of  Tomes,*  who  says  that 
"ninety-nine  out  of  every  one  hundred  cases  are  due  to  exposure  of  the 
pulp."' 


*  Tomes's  Dental  Surgery,  4th  edition,  p.  380. 


INFLAMMATION  OF  THE  DENTAL  PULP.  403 

In  those  cases  which  develop  after  the  carious  cavity  has  been  filled, — 
secondary  cases, — minute  exiDOSures  of  the  pulp  involving  one  of  the  cornua, 
— incomplete  exposures,  or  pseudo-exposures, — which  permit  pressure  to  be 
exerted  upon  the  pulp  by  reason  of  the  thinness  and  decalcified  condition 
of  the  wall  of  the  pulp-chamber,  and  thermal  shock  aggravated  by  the 
presence  of  metallic  fillings  are  the  principal  causes  ;  the  latter,  however, 
are  the  most  prolific  of  inflammatory  conditions,  by  reason  of  the  fact 
that  in  incomplete  and  pseudo-exposures  the  pulp  has  generally  been 
protected  by  some  form  of  non-conducting  capping,  which  in  a  measure 
prevents  or  lessens  thermal  shock  in  these  cases. 

Exposure  of  the  pulp  to  the  fluids  of  the  mouth  permits  the  entrance 
of  the  pyogenic  micro-organisms  and  establishes  septic  inflammation,  which 
almost  invariably  terminates  in  suppuration.  It  is  possible,  however,  for 
a  septic  inflammation  to  occur  in  the  pulp  without  direct  exposure  of  any 
part  of  this  organ  :  first,  by  the  penetration  of  the  softened  and  decalcified 
dentin  by  the  pyogenic  or  pus-producing  micro-organisms  which  in  their 
growth  follow  the  dentinal  tubuli,  thus  gaining  access  to  the  tissues  of  the 
pulp  ;  secondly,  by  the  presence  of  these  organisms  in  the  blood,  which 
have  gained  access  to  this  fluid  through  some  external  wound  or  abrasion 
of  the  skin  or  mucous  membrane,  or  from  some  pre-existing  suppurating 
wound  or  abscess,  forming  secondary  abscesses  just  as  metastatic  abscesses 
are  formed  in  other  portions  of  the  body  by  the  lodgement  of  these  organ- 
isms in  the  capillary  blood-vessels  or  glandular  structures,  forming  a  nidus, 
where,  under  favoring  conditions  of  a  weakened  local  vitality,  they  rapidly 
propagate. 

Pathology. — Inflammation  of  the  dental  pulp  is  in  no  way  different 
from  inflammation  as  observed  in  other  connective  tissues.  It  follows  the 
same  course,  by  the  establishment  of  hypersemia,  the  exudation  of  leu- 
cocytes and  their  proliferation,  the  formation  of  infarcts,  the  escape  of 
red  blood- corpuscles,  the  coagulation  of  the  fibrinous  elements,  and  either 
resorption  ending  in  resolution,  the  organization  of  the  escaped  cells 
into  new  tissue,  the  liquefaction  of  the  exudates  and  the  formation  of 
pus,  the  death  of  the  puli^  en  masse,  followed  by  putrefaction  —  moist 
gangrene— and  the  formation  of  mephitic  gases  in  those  cases  in  which  the 
pulj)  has  been  exposed  to  septic  influences,  or  by  mummification — djy  gan- 
grene— in  those  cases  in  which  the  pulp  has  not  been  exposed  to  septic 
infections. 

Acute  Circumscribed  Pulpitis. — Acute  circumscribed  infiammation 
of  the  pulp  is  usually  found  in  those  cases  in  which  the  walls  of  the  pulp- 
chamber  has  been  perforated,  exposing  the  surface  of  the  pulp  at  this 
point  to  external  irritating  and  septic  influences.  The  area  thus  affected 
is  sometimes  very  minute  ;  at  others  it  involves  a  considerable  portion  of 
the  surface  of  the  pulp.  The  microscope  reveals  in  the  early  stage  of  the 
inflammation  a  more  or  less  extensive  area  immediately  beneath  the  in- 
flamed surface,  occupied  by  the  inflammatory  exudates,  and  smaller  areas, 
which  are  colored  red,  the  result  of  the  formation  of  thrombi  and  infarcts 
and  the  escape  of  the  red  blood- corpuscles. 

Suppuration  is  later  established  upon  the  surface,  and  minute  coUec- 


404  OPERATIVE    DENTISTRY. 

tions  of  pus-corpuscles  may  be  fouud  in  the  deeper  structures  of  tlie 
organ. 

The  character  of  the  iuflammation  now  depends  upon  the  extent  of  the 
opening  in  the  pulp -chamber,  the  activity  of  the  phagocytes,  and  the 
dyscrasia  or  diathesis  of  the  patient.  When  the  perforation  in  the  wall 
of  the  pulp-chamber  is  so  small  as  to  prevent  a  free  escape  of  the  pus 
which  is  formed  at  the  point  of  exposure  the  suppurative  inflammation 
becomes  more  acute,  and  the  entire  pulp  is  soon  involved,  ending  in  its 
speedy  destruction.  But  when  the  perforation  is  so  large  that  the  pus 
formed  upon  the  surface  finds  a  ready  exit,  the  suppurative  process  is  apt 
to  be  prolonged  for  an  indefinite  period,  the  character  of  the  process  be- 
coming subacute  or  chronic  in  its  manifestations  with  the  formation  of  an 
ulcerating  surface. 

On  the  other  hand,  if  the  patient  is  of  a  scrofulous,  tuberculous,  or 
syphilitic  diathesis,  or  is  suffering  from  malaria,  diabetes  mellitus,  or  albu- 
minuria, the  suppurative  inflammatory  process  will  run  a  rapid  course, 
ending  in  a  few  days  at  most  in  the  destruction  of  the  pulp  ;  while  if  the 
individual  is  in  fair  health  and  of  good  constitution,  the  tendencies  are 
towards  resolution  or  a  subacute  or  chronic  inflammation. 

Acute  Diffuse  or  General  Pulpitis. — Acute  diffuse  or  general  inflam- 
mation of  the  pulp  is  the  most  common  result  of  all  forms  of  irritation  of 
whatever  nature,  whether  mechanic,  chemic,  septic,  or  nervous.  It  may 
occur,  as  already  pointed  out,  with  or  without  perforation  of  the  pulp- 
chamber. 

The  character  of  the  inflammation  is  such  that  it  speedily  causes  stasis 
of  the  blood-current  by  general  infarction  or  thrombosis,  unless  the  per- 
foration in  the  wall  of  the  pulp-chamber  is  sufficiently  large  to  permit 
expansion  or  swelling  of  the  tissues  to  a  degree  that  will  relieve  the  press- 
ure upon  the  blood-vessels  at  the  apical  end  of  the  pulp- chamber. 

The  result  of  general  infarction  is  death  of  the  pulp  en  masse.  Inflam- 
mation, however,  both  acute,  circumscribed,  and  diffuse,  may  be  induced  by 
infarcts  in  limited  areas  within  the  body  of  the  pulp,  caused  by  intense 
hypersemia,  as  pointed  out  by  Black.*  Extravasation  of  red  blood- corpus- 
cles and  their  disintegration  frequently  occurs  as  a  i-esult  of  infarction. 
The  disintegration  of  these  corpuscles  and  the  dissemination  of  their  col- 
oring matter  through  the  substance  of  the  dentin  exi3lains  the  jDinkish  hue 
which  often  obtains  after  the  death  of  the  pulp,  and  which,  from  the  grad- 
ual decomiDOsition  of  the  haemoglobin  thus  disseminated,  progressively 
changes  the  color  of  the  dentin  to  brown,  blue,  and  blue-black. 

Symptoms  and  Diagnosis. — The  symptoms  of  acute  pulpitis  must  be 
studied  from  two  aspects  :  first,  those  cases  in  which  there  is  no  exposure 
of  the  pulp  ;  second,  those  which  present  exi^osure  and  are  necessarily 
septic.  The  symptoms  of  inflammation  of  the  pulp  are  so  nearly  like 
those  of  hypersemia  that  differentiation  between  them  becomes  extremely 
difficult.  Black  thinks  that  in  pulpitis  the  pain  is  less  paroxysmal  and 
more  inclined  to  be  prolonged. 

*  American  System  of  Dentistry,  vol.  i.  p.  846. 


INFLAMMATION    OP   THE    DENTAL   PULP.  405 

On  account  of  the  unyielding  nature  of  the  walls  of  the  pulp-chamber 
the  symptoms  of  acute  pulpitis  are  generally  active  and  violent,  and  are 
characterized  by  sharp,  stinging,  lancinating,  throbbing  pain,  at  times 
continuous ;  in  other  cases  the  pain  may  be  paroxysmal  in  character,  in- 
creasing in  intensity  until  it  becomes  almost  unbearable,  then  slowly  sub- 
siding, the  exacerbations  occurring  with  short  intervals  of  a  few  minutes 
or  with  larger  intervals  of  an  hour  or  two.  In  those  cases  presenting  with- 
out exposure  of  the  pulp  the  inflammation  runs  a  rapid  course,  and  the 
vitality  of  the  pulp  may  be  destroyed  in  a  few  hours  from  venous  conges- 
tion, terminating  in  complete  stasis,  induced  by  j)ressure  upon  the  arteries 
entering  the  apical  foramen.  In  those  presenting  exi^osure  of  the  pulp, 
the  inflammatory  symj)toms  may  be  prolonged  for  several  days,  and  finally 
end  in  complete  stasis  and  death  en  masse  by  the  same  mechanic  obstruc- 
tion to  the  circulation,  or  the  inflammatory  symptoms  may  assume  a  chronic 
form  and  be  prolonged  indefinitely.  Exercise  or  the  recumbent  position 
increases  the  violence  of  the  pain  in  the  acute  form  of  inflammation,  as 
does  also  excessive  changes  in  the  temperature,  pressure  from  foreign  sub- 
stances in  the  cavity,  or  the  irritation  from  sweets,  acids,  or  salt. 

In  those  cases  where  there  is  no  exposure  of  the  pulp  the  symx^toms  are 
usually  most  severe  but  brief  in  their  duration,  and  they  are  much  less 
liable  to  suppuration  or  decomi^osition  by  reason  of  the  exclusion  of  the 
micro-organisms  from  external  sources. 

On  the  other  hand,  in  those  cases  presenting  an  exposure  of  the  pulp, 
the  symptoms  are  generally  less  severe,  but  are  more  prolonged,  the  course 
of  the  inflammation  being  modified  by  the  opportunity  for  expansion  and 
protrusion  of  a  portion  of  the  x>ulp — hernia — under  the  pressure  of  the 
distended  blood-vessels,  which  is  made  possible  by  the  break  in  the  con- 
tinuity of  the  walls  of  the  pulp- chamber. 

The  exposure  of  the  pulp  to  the  influence  of  the  sei3tic  conditions  of  the 
carious  cavity  and  of  the  secretions  of  the  mouth  introduces  a  complication 
which  renders  any  attempt  at  conservative  treatment  much  more  diflicult 
than  would  be  the  case  if  micro-organisms  from  external  sources  had  not 
come  in  contact  with  it. 

The  break  in  the  continuity  of  the  walls  of  the  pulp-chamber  causes 
another  complication  which  often  greatly  aggravates  the  suffering  endured 
in  acute  inflammation  by  permitting  the  pulp,  which  is  often  greatly 
distended  with  blood,  to  press  upon  the  sharp  and  irregular  edges  of 
the  perforation,  producing  shxingulated  hernia  of  the  puli?.  Eelief  is 
only  obtained  after  depleting  the  organ  by  puncturing  or  scarifying  its 
surface. 

Prognosis. — The  prognosis  of  acute  pulpitis  has  generally  been  con- 
sidered as  extremely  problematic,  and  therefore  efforts  at  conservation  of 
the  organ  under  such  conditions  have  never  received  much  suijport  from 
the  profession  at  large.  That  the  dental  pulp  may  under  the  favorable 
circumstances  of  good  general  health  and  hygienic  surroundings  finally 
recover  from  acute  inflammation  which  has  not  progressed  to  the  stage  of 
suppuration  there  is  not  the  least  doubt,  as  can  be  attested  by  numerous 
cases  and  the  clinical  exx^erience  of  many  operators.     And  yet  the  fact 


406  OPERATIVE   DENTISTRY. 

remains  that  in  many  of  these  seeming  cases  of  recovery  supplementary 
pathologic  changes  have  occurred,  usually  of  a  degenerative  type,  like 
calcareous  deposits  or  fatty  metamorphosis,  which  have  finally,  after 
months,  or  perhaps  years,  terminated  in  devitalization  and  decomposition, 
or  dry  gangrene. 

Treatment. — The  treatment  of  acute  pulpitis  may  be  both  local  and 
systemic.  As  a  rule,  however,  local  treatment  will  usually  be  sufficient  to 
control  the  symptoms,  but  when  these  measures  fail,  as  occasionally  hap- 
pens, systemic  treatment  may  prove  of  inestimable  value. 

Local  treatment  consists  in  first  freeing  the  carious  cavity  from  all  foreign 
substances  and  irrigating  it  with  an  alkaline  solution,  like  soda  bicarbonate, 
one  drachm,  tepid  water,  one  fluidounce,  to  neutralize  the  acid  condition  of 
the  disorganized  dentin.  The  cavity  is  then  dried  and  the  same  local  meas- 
ures employed  as  indicated  in  the  treatment  of  hypersemia  of  the  pulp.  The 
most  efficient  means  which  can  be  emj^loyed  to  give  relief  in  those  cases 
complicated  with  exposure  of  the  pulp  is  depletion  by  direct  puncture  or 
incision  of  the  exposed  organ.  Cocaine  hydrochlorate — ten  to  twenty- 
five  per  cent,  solution — should  be  applied  to  the  pulp  after  adjusting  a 
rubber  dam,  and  in  from  two  to  five  minutes  the  iduIx)  will  have  been  suffi- 
ciently anaesthetized  upon  the  surface  to  permit  of  its  puncture  or  incision 
without  pain.  Chloretone  solution,  made  by  mixing  equal  parts  by  weight 
of  ether  and  chloretone,  may  be  applied  to  the  exposed  pulp  upon  a 
pledget  of  cotton  for  the  same  purpose.  After  the  vessels  have  been  de- 
pleted the  pulp  may  be  dressed  with  some  efficient  sedative  and  antiseptic 
remedy  like  the  following  :  morphine  sulphate,  one-tenth  grain,  atroiDine, 
one-hundredth  grain,  dissolved  in  a  drop  of  oil  of  cloves.  The  hypodermic 
tablets  of  morphine  and  atropine  in  these  proportions  can  always  be  pro- 
cured and  kept  on  hand  ready  for  use,  and  may  be  prepared  for  applica- 
tion to  the  cavity  by  first  crushing  the  tablet  upon  a  glass  or  porcelain 
mixing-slab  and  then  adding  a  drop  of  oil  of  cloves.  It  is  then  gathered 
upon  a  pledget  of  cotton,  placed  in  the  bottom  of  the  cavity,  and  sealed 
in  with  zinc  oxyphosphate,  mixed  thin,  and  inserted  in  this  condition,  so 
that  no  pressure  will  be  brought  to  bear  upon  the  exposed  pulp.  Tempo- 
rary stoppings  which  permit  the  percolation  of  the  septic  oral  secretions 
through  or  around  them  should  be  avoided,  as  success  in  the  treatment  of 
these  cases  will  depend  largely  upon  maintaining  aseptic  conditions  of  the 
cavity  and  the  pulp.  Another  efficient  remedy  for  relieving  the  pain  in 
acute  pulpitis  is  a  x>aste  made  of  cocaine  hydrochlorate  in  glycerol,  ap- 
plied as  above.  Saturated  solutions  of  menthol  and  thymol  are  also 
recommended  for  the  same  purpose. 

Another  method  of  relieving  the  congested  condition  of  the  pulp  is  the 
abstraction  of  blood  from  the  engorged  veins  and  cax)illaries  of  the  gums, 
directly  over  the  affected  tooth,  by  scarification,  and  promoting  the  flow 
of  blood  by  the  application  of  warm  water  held  in  the  mouth.  The  ab- 
straction of  blood  by  the  application  of  leeches  is  an  old  method,  and  still 
advocated  by  some  authorities.  The  dangers  from  infection,  however,  are 
so  great  from  the  use  of  this  method  that  its  application  is  inexcusable  in 
these  days  of  enlightened  aseptic  surgery. 


INFLAMMATION    OF    THE    DENTAL    PULP.  407 

Counterirritation  is  sometimes  useful  in  relieving  the  congestion  of  tlie 
vessels  of  the  pulp  by  drawing  the  blood  to  the  surface.  This  may  be 
accomplished  by  the  continued  use  of  capsicum  plasters  applied  to  the 
gum  over  the  affected  tooth  ;  painting  the  gum  with  tincture  of  aconite 
and  tincture  of  iodine,  equal  parts,  or  by  drying  the  gum  and  painting  it 
with  cantharidal  collodion,  which  raises  a  blister.  Care  should  be  taken 
to  paint  only  a  small  area,  as  the  irritation  induced  by  the  blister  renders 
the  gum  very  sensitive  for  several  days. 

Systemic  treatment  consists  of  the  administration  of  general  sedative  and 
analgesic  remedies.  Ten  grains  of  Dover's  jjowder  administered  at  bed- 
time, or  five  to  ten  grains  of  antikamnia,  or  ten  grains  of  ammonol,  will 
usually  insure  a  quiet  night.  A  hot  foot-bath  just  before  retiring  may  be 
supplemented  with  advantage,  as  this  is  a  useful  means  of  equalizing  the 
circulation  and  relieving  arterial  tension  in  the  upper  portion  of  the  body. 
A  brisk  saline  cathartic  is  also  a  valuable  additional  means  of  relieving 
the  determination  of  the  blood  to  the  affected  part. 

After  the  inflammatory  symptoms  have  been  relieved  and  the  pulp 
becomes  quiescent,  the  question  of  the  after-treatment  must  be  settled,  — 
viz.,  whether  conservation  shall  be  attempted  or  the  pulp  devitalized.  The 
settlement  of  this  question  calls  for  a  clear  insight  into  the  local  and  con- 
stitutional conditions  which  surround  the  case,  and  good  judgment  is 
required  in  the  final  decision,  for  if  the  operator  would  render  his  patient 
the  best  possible  service  in  each  individual  case  he  must  be  free  from  all 
bias  or  prejudice  and  ready  to  act  as  his  best  judgment  dictates. 

■  SUPPURATION  OF  THE  DENTAL  PULP. 

Definition. — The  term  suppuration  comes  from  the  Latin  suppuratio, 
from  suppurare,  to  form  pus.     The  formation  of  pus. 

Suppuration  is  the  most  frequent  termination  of  acute  inflammation. 
An  inflammation  which  terminates  in  this  manner  is  termed  suppurative 
inflammation. 

Suppuration  is  a  process  by  which  the  morphologic  elements  found  in 
the  inflammatory  exudates— the  leucocytes  and  the  embryonic  cells  formed 
from  the  fixed  tissue-cells — are  converted  into  pus- corpuscles  and  the  in- 
tercellular substance  of  the  tissue  is  liquefied. 

The  conversion  of  the  leucocytes  and  embryonic  cells  and  the  liquefac- 
tion of  the  intercellular  substance  to  form  pus  are  i)roduced  by  a  peculiar 
peptonizing  or  digestive  action  of  the  pyogenic  micro-organisms. 

The  causes  of  suppuration  may  be  divided  into  indirect  and  direct. 

The  indirect  causes  of  suppuration  are  the  inflammatory  phenomena  of 
exudation,  the  crowding  of  the  connective- tissue  sj^aces  with  the  corpus- 
cular elements  of  the  blood,  and  the  consequent  pressure  uj)on  the  capillary 
blood-vessels,  resulting  in  complete  stasis  and  death  of  the  tissues  invoh-ed. 
Death  of  the  tissues,  however,  is  not  always  necessary  to  produce  suppu- 
ration, but  the  changes  which  take  place  in  the  affected  parts  are  those 
which  are  expected  to  follow  intense  irritation, — viz.,  hypertemia,  exuda- 
tion, coagulation  of  the  fibrinous  elements,  and  partial  stasis. 

The  direct  caiises  of  suppuration  are  certain  specific  micro-organisms — 


408 


OPERATIVE    DENTISTRY. 


the  pyogenic  bacteria — and  tlieir  peptonizing  effect  upon  the  leucocytes^ 
embryonic  cells,  and  intercellular  substance  of  the  tissues. 

In  the  suppuration  due  to  the  presence  of  the  pyogenic  bacteria — in- 
fectious inflammations — the  direct  cause  which  produces  it  multiplies  in 
the  tissues.  Consequently  its  tendency  is  to  become  progressive,  while 
from  the  pus  produced  by  this  form  of  inflammation  the  pathogenic  micro- 
organisms— the  staphylococci  and  streptococci — can  be  cultivated,  and  if  in- 
troduced into  another  organism  will  produce  inflammation  and  suppuration. 

Pus  may  be  j)roduced,  however,  under  certain  circumstances  without 
the  presence,  aid,  or  intervention  of  micro-organisms,  as,  for  instance, 
by  the  introduction  beneath  the  skin  of  certain  irritating  chemical  sub- 
stances. Councilman  was  the  first  to  prove  the  fact  that  croton  oil  when 
injected  beneath  the  skin  of  rabbits  would  produce  suppuration  without 
the  action  of  micro-organisms.  The  early  experiments  in  this  line  gave 
very  conflicting  results.  Some  investigators  succeeded  in  producing  an 
aseptic  pus  which  would  not  cause  suppuration  when  introduced  into 
another  organism,  while  others  produced  a  septic  product  with  the  same 
chemic  agent.  These  conflicting  results  were  due  in  some  cases  to  imper- 
fect aseptic  methods  ;  in  others  to  the  fact  that  the  same  chemic  substance 
would  produce  suppuration  in  one  species  of  animal  and  not  in  another, 
as  pointed  out  by  Christmas,  who  was  unable  to  produce  suppuration  in 
rabbits  with  turpentine  or  mercury,  but  succeeded  with  dogs. 

Fig.  502. 


Suppuration  of  the  dental  pulp  is  in  nowise  different  from  suppuration  as 
observed  in  other  connective  tissues,  except  that  which  relates  to  its  loca- 
tion and  peculiar  environment.  It  is  found  most  commonly  associated 
with  exposure  of  this  organ  and  under  large  fillings,  the  pulp  of  the  tooth 
having  been  previously  inflamed. 


INFLAMMATION    OF   THE    DENTAL    PULP. 


409 


Fig. 

I'll 


mm 
mm 


503. 


Supi)uration  of  the  pulp  presents  in  two  forms,  superficial  and  paren- 
chymatous, and  may  be  either  acute  or  chronic  in  its  manifestations. 

Acute  superficial  suppuration  of  the  pulp,  or  ulceration,  is  a  destructive 
loss  or  solution  of  continuity  of  the  exposed  surface  of  the  organ  ;  a  molec- 
ular death  of  tissue,  which  will  not  permit  of  repair  by  xDrimary  union, 
and  owes  its  existence  to  the  fact  that  the  retrograde  changes  or  metamor- 
phoses are  in  excess  of  those  of  repair.  Change  the  relationshijp  between 
these  conditions  and  the  ulceration  will  heal  by  granulation,  just  as  is  seen 
in  ulcerations  upon  the  free  surfaces  of  the  body.  If  unchecked,  the 
ulcerative  process  tends  to  gradual  but  final  destruction  of  the  whole  organ. 

Fig.  502  shows  a  section  by  Black 
taken  from  an  inflamed  area.  The 
blood-vessels  are  represented  as  empty 
to  bring  them  more  prominently  into 
view,  but  in  reality  they  are  filled  with 
coagulated  blood.  It  will  be  further 
noticed  that  the  normal  cells  have 
nearly  all  disappeared,  and  that  their 
places  have  been  occupied  by  the  in- 
flammatory products  of  exudation. 
Opposite  the  point  of  exposure  (a)  the 
odontoblastic  layer  has  been  destroyed 
and  a  pus-pocket  formed  in  the  deeper 
substance  of  the  pulp,  while  at  h  the 
odontoblastic  layer  has  been  consider- 
ably undermined.  This  undermining  of 
the  odontoblastic  layer  Dr.  Black  found 
to  be  the  general  rule  in  progressive 
suxDpuration  or  ulceration  of  the  pulp. 

Fig.  503  represents  a  longitudinal 
section  taken  from  a  case  of  pro- 
gressive suppuration  or  ulceration  of 
the  pulp  of  an  incisor,  and  shows  that 
the  destructive  process  follows  the 
course  of  the  veins,  progressively  de- 
stroying the  tissue  as  it  advances  from 
the  iDoint  of  exposure  to  the  apex. 

Acute  parenchymatous  suppuration 
of  the  pulp,  or  abscess,  is  an  accumula- 
tion of  pus  in  the  parenchyma  of  the 
organ  surrounded  by  a  wall  of  lymph. 
It  owes  its  existence  to  the  action  of 
an  excessive  and  continuous  irritation 
which  has  caused  a  copious  exudation, 
the  filling  of  the  connective- tissue 
spaces,    pressure   upon  the   capillary 

blood-vessels  causing  stasis,  followed  by  coagulation  of  the  fibrinous  ele 
ments.     The  leucocytes  lose  their  vitality,  while  pressure  upon  the  con^ 


Progressive  suppuration  of  tlie  pulp.  (After 
Black.)  X  100.  a,  healthy  tissue ;  6,  odonto- 
blastic layer ;  c,  inflamed  tissue  showing  di- 
lated veins ;  d,  line  of  demarcation  of  suppu- 
rative process ;  e,  pus. 


410 


OPERATIVE    DEXTLSTRY. 


necti^-e-tissue  cells  involved  in  the  affected  area  produces  a  like  result  in 
them,  and  by  the  action  of  the  pyogenic  bacteria  which  have  gained  access 
through  external  channels,  or  through  the  avenue  of  the  circulation,  the 
exudates  and  the  tissues  are  converted  into  pus.  These  abscesses  are  usu- 
ally situated  near  the  point  of  exposure,  and  are  rarely  found  singly. 
Black  says  it  is  not  uncommon  to  find  several  minute  pus-pockets  at  a 
little  distance  from  the  point  of  exposure.  The  abscess  may,  however, 
occupy  the  central  portion  of  the  pulp.  Burchard  removed  such  a  pulp, 
the  abscess  involving  nearly  its  entire  structure,  but  leaving  the  peripheral 
portion  unbroken,  as  shown  in  Fig.  504. 

Fig.  504. 


Transverse  section  of  pulp  of  inferior  bicuspid,  partly  diagrammatic.     (After  Burchard.)     a,  abscess 
cavity ;  6,  embryonic  cells  at  periphery  of  abscess  cavity ;  c,  occluded  blood-vessels. 


Black  has  found  abscesses  in  the  deeper  structures  of  the  pulp,  most 
frequently  in  the  molars.  Fig.  505  shows  such  an  abscess  in  a  central  in- 
cisor, about  midway  of  its  length,  the  coronal  portion  of  which  was  sup- 
purating, while  the  evidences  of  inflammation  within  the  deeper  structures 
was  rather  more  extended  than  is  common. 

Suppurative  inflammation  of  the  pulp  under  capiDings  and  large  fillings 
used  to  be  a  frequent  occurrence  before  the  introduction  of  antiseptics  in 
the  treatment  of  surgical  wounds.  To-day,  however,  such  occurrences  are 
much  more  rare  by  reason  of  the  improved  methods  of  treatment  which 
have  been  based  upon  this  great  scientific  discovery. 

Symptoms  and  Diagnosis. — The  formation  of  an  abscess  in  the  soft 
tissues  of  the  body  causes  considerable  swelling,  and  when  the  swelling  is 
hindered  by  overlying  and  unyielding  fascia  the  pain  becomes  very  intense, 
and  the  pus  burrows  along  courses  which  offer  the  least  resistance,  often 
forming  long  and  tortuous  channels  in  the  effort  to  reach  a  point  of  exit. 

In  suppuration  of  the  pulp  with  a  minute  i)erforation  of  the  wall  of  the 
pulp-chamber,  or  under  a  capping  or  a  large  filling,  the  pus  is  held  back, 
and  as  it  accumulates,  causes  pressure  upon  the  tissues  of  the  pulp,  which 


INFLAMMATION  OF  THE  DENTAL  PULP. 


411 


either  give  way  or  are  destroyed.  The  pain  which  is  induced  by  this  pro- 
cess is  different  from  that  caused  by  hypersemia,  in  that  the  onset  of  the 
attack  is  not  so  sudden  nor  so  violent.  It  begins  with  a  dull,  heavy,  gnaw- 
ing sensation,  which  gradually  increases  in  intensity  to  the  most  violent 
and  almost  unendurable  pain.  The  duration  of  the  pain  is  governed  by 
the  amount  and  rapidity  with  which  the  pus  is  formed.  Sometimes  the 
accumulation  of  the  pus  is  so  rapid  that  the  vitality  of  the  pulp  is  destroyed 
in  a  few  liours  ;  at  others  devitalization  may  not  occur  under  twenty-four 
to  forty-eight  hours.  Death  of  the  pulp  is  induced  by  the  pressure  upon 
the  apical  blood-vessels,   causing  general  infarction.     Evacuation  of  the 

Fig.   505. 


The  field  includes  about  one-half  of 


Abscess  within  the  tissues  of  the  pulp.     (After  Black.)    X  250. 

the  little  pocliet  of  pus. 

pus  by  opening  the  pulp-chamber  gives  almost  instant  relief  from  the 
severe  symptoms.  Sometimes  when  the  pus  is  deep-seated  it  becomes 
necessary  to  puncture  the  abscess  with  a  probe.  The  amount  of  pus  which 
is  occasionally  contained  in  a  pulp-chamber  is  surprisingly  large,  at  times 
welling  up  in  such  quantity  as  to  nearly  fill  a  large  cavity  of  decay.  The 
pressure  under  such  circumstances  must  have  been  very  considerable  in- 
deed, and  thus  accounts  for  the  intense  character  of  the  pain.  In  from  six 
to  twenty-four  hours  after  the  cessation  of  the  pain  symptoms  of  apical 
irritation  begin  to  be  manifest  unless  the  pulp-chamber  has  been  opened 
and  the  pus  is  evacuated. 

The  presence  of  small  abscesses  within  the  parenchyma  of  the  pulp  are 
not  always  productive  of  severe  pain,  and  they  may  be  retained  for  an 
indefinite  period,  and  finally  absorbed.     (Black.) 

Accumulations  of  pus  within  the  pulp  may,  as  in  other  locations  of  the 
body,  undergo  fatty  degeneration,  as  pointed  out  by  Salter.  Decomposi- 
tion of  the  retained  pus  may  take  place  with  the  generation  of  mephitic 
gases.  Black  says  upon  this  point,  ' '  Warm  liquids  when  taken  into  the 
mouth  should  increase  the  pain  by  expanding  the  gases,  while  cold  would 
relieve  it  by  the  opposite  effect."     This  is  a  diagnostic  fact  of  considerable 


412  OPERATIVE    DENTISTRY. 

importance,  and  should  always  be  borne  in  mind  in  diagnosing  the  various 
forms  of  acute  pulpitis. 

Treatment. — The  treatment  of  this  class  of  cases  requires  the  im- 
mediate opening  of  the  pulp-chamber,  the  evacuation  of  the  pus,  and  anti- 
septic treatment  of  the  suppurating  pulp.  Although  it  is  possible  under 
favorable  circumstances  to  control  the  suppurative  process  and  relieve  the 
inflammatory  symptoms,  efforts  at  conservation  of  the  pulp  are  not  favor- 
able, for  the  reason  that  they  so  rarely  succeed.  It  is,  therefore,  the  wiser 
plan  to  devitalize  the  pulp  and  remove  it  as  soon  as  the  inflammatory 
symptoms  are  under  control. 

CHEONIC  INFLAMMATION  OF  THE  DENTAL  PULP. 

Chronic  pulpitis  is  usually  a  sequel  of  the  acute  form  of  inflammation, 
but  it  may  occasionally  be  due  to  a  low  grade  of  irritation  which  has  never 
been  of  sutflcient  severity  to  produce  other  than  a  mild  but  continuous 
hypersemia  of  its  blood-vessels,  such  an  irritation  as  would  accompany  the 
gradual  wearing  down  of  the  teeth  from  mechanic  abrasion  or  chemic 
erosion  with  the  formation  of  secondary  deposits,  as  already  pointed  out 
in  Chapter  XXII. 

Chronic  pulpitis,  which  is  the  sequel  of  the  acute  stage,  may  present 
itself  in  either  of  three  common  forms, — viz.,  chronic  suppurative  inflamma- 
tion, hypertrophic  inflammation,  and  degenerative  inflammation. 

Chronic  suppurative  inflammation  of  the  pulp  is  almost  always  confined  to 
the  surface  of  the  pulp  in  connection  with  perforations  of  the  wall  of  the 
puli3-chamber,  which  are  small  or  moderate  in  extent,  but  which  allow  of 
the  free  escape  of  the  pus  as  rapidly  as  it  forms.  If  for  any  reason  the 
accumulations  of  pus  are  retained,  active  symptoms  usually  supervene, 
and  acute  abscess  of  the  pulp  is  the  result. 

Chronic  suppuration  of  the  pulp  tends  sooner  or  later  to  cause  its  de- 
struction either  by  molecular  death  (ulceration)  and  devitalization  of  its 
tissue,  or  by  death  en  masse  (gangrene)  of  extensive  portions  and  sloughing 
of  the  gangrenous  areas.  Severe  pain  is  rarely  present  in  this  form  of  in- 
flammation, unless  the  opening  into  the  pulp -chamber  becomes  stopped  up 
with  food  debris,  or  the  cavity  is  filled  with  a  septic  dressing.  The  removal 
of  these  obstructions  to  the  escape  of  the  pus  gives  immediate  relief. 

The  heat  sense  is  greatly  lessened,  as  is  also  its  general  sensitiveness  to 
chemic  irritants  and  to  pressure  or  instrumentation. 

The  only  reliable  treatment  in  this  form  of  inflammation  of  the  pulp  is 
devitalization  and  extirpation.  Conservative  treatment  based  upon  the 
possibility  of  the  suppurating  surface  becoming  cicatrized  and  the  pulp 
being  capable  afterwards  of  performing  its  normal  functions  rests  upon 
such  meagre  clinical  evidence  that  it  cannot  be  recommended  except  as  a 
purely  experimental  study. 

Sypertrophic  inflammation,  or  polyj)us  of  the  i^ulp,  can  occur  only  when 
the  walls  of  the  X3ulp-chamber  have  been  perforated  to  a  considerable  extent, 
for  when  they  are  intact  there  is  no  ijossibility  of  enlargement,  by  reason 
of  the  fact  that  there  is  no  room  in  the  pulp-chamber  for  such  growth. 

The  size  of  the  perforation  in  the  walls  of  the  pulp-chamber  determines 


INFLAMMATION    OF    THE    DENTAL    PULP.  413 

to  a  certain  extent  the  size  and  the  character  of  the  new  growth.  In  small 
perforations  the  pulp  protrudes  but  slightly,  except  when  acute  inflam- 
matory symptoms  are  present,  as  already  indicated  upon  a  previous  page. 

When  the  perforation  in  the  wall  of  the  pulp-chamber  is  large,  the  pulp 
may  bulge  from  the  opening,  forming  a  large  fleshy  mass  {polypus  ofthepidp'), 
which  may  be  so  large  as  to  fill  the  entire  cavity  of  decay,  and  even  pro- 
trude beyond  it.  This  condition  is  more  commonly  seen  in  young  persons 
at  the  period  of  adolescence  and  in  scrofulous  and  tuberculous  individuals. 

In  the  early  stages  of  the  growth  or  hypertrophy  of  this  tissue  it  is  very 
sensitive,  but  later,  as  it  increases  in  size,  it  gradually  becomes  less  and  less 
sensitive  until,  comparatively,  it  is  no  more  sensitive  than  the  gum-tissue. 

The  hypertrophied  mass  is  composed  of  vascular  distentions,  granula- 
tion-tissue, and  connective-tissue  fibres,  the  whole  mass  being  covered  with 
a  thick  epithelium.  In  general  appearance  it  is  so  like  gum-tissue  that  it 
is  with  extreme  difficulty  that  it  can  be  distinguished  clinically  from  that 
tissue.  It  may  be  difi'erentiated  from  a  gum  festoon  which  has  grown  into 
the  cavity  of  decay  by  the  fact  that  it  is  connected  to  the  pulp  by  a  narrow 
constricted  pedicle,  and  that  a  probe  can  be  made  to  pass  beneath  it  and 
completely  around  the  whole  circumference  of  the  cavity  of  decay,  while 
a  gum  festoon  which  occupies  the  cavity  can  be  lifted  out,  and  will  be  found 
to  be  connected  with  the  gum  at  the  cervical  margin  by  a  broad  pedicle. 

Hypertrophied  tissue  will  be  found  to  be  quite  difiicult  to  destroy  with 
arsenic  or  other  escharotics.  Before  attempting  devitalization  the  mass 
should  be  amputated  at  the  bottom  of  the  cavity  by  severing  the  narrow 
pedicle,  and  as  soon  as  hemorrhage  has  ceased  arsenic  may  be  applied 
to  the  stump  and  the  case  treated  as  an  ordinary  exposure. 

Calcification  of  an  hypertrophied  pulp  has  been  known  to  occur. 
Tomes  *  mentions  a  case  reported  by  Eogers,  in  which  hypertrophy  of  a 
pulp  took  place  after  the  crown  of  an  upper  molar  tooth  was  removed  in 
an  unsuccessful  attempt  to  extract  it,  leaving  the  pulp  exposed.  Some 
months  afterwards  the  roots  were  removed,  and  the  hypertroj)hied  pulp  was 
found  to  have  extended  over  the  sharp  edges  of  the  pulp-chamber  and  to 
be  completely  calcified.  Black  f  described  a  somewhat  similar  case  occur- 
ring under  a  metallic  capping,  and  Heider  and  Wedl  |  figure  a  case  in  their 
atlas  of  a  similar  condition  occurring  in  an  incisor  tooth  of  an  antelope. 

Another  result  of  hypertrophic  inflammation  of  the  i^ulp  is  the  re- 
sorption of  the  dentin  surrounding  the  pulp,  causing  enlargement  of  the 
pulp-chamber.  Such  conditions  are,  however,  very  rarely  met  with  in 
clinical  practice.  Black  mentions  a  case  of  this  character  occurring  in  a 
first  lower  molar  which  he  had  capped  for  exposed  pulp  ten  years  before 
and  had  inserted  a  large  gold  filling.  Irritation  of  the  pulp  had  persisted 
for  the  last  two  or  three  years.  On  removing  the  filling  the  pulp-chamber 
was  found  to  be  enormously  enlarged,  and  an  opening  to  the  peridental 
membrane  had  occurred  at  the  bifurcation  of  the  roots. 


*  Tomes' s  Dental  Surgery,  4th  ed.,  p.  367. 

t  American  System  of  Dentistry,  vol.  i.  p.  859. 

X  Atlas  of  Pathology  of  the  Teeth. 


414 


OPERATIVE    DENTISTRY. 


In  another  case,  a  central  incisor,  the  enlargement  of  the  pnlp-chamber 
was  not  so  great,  but  was  unmistakable. 

The  writer  saw  a  similar  case  in  consultation  with  the  late  Dr.  W.  W. 
Allport,  occurring  in  a  first  superior  bicuspid,  the  pulp  of  which,  accord- 


FiG.  506. 


Fig.  507. 


Pulpitis.  ( After  Bodecker.)  y  300.  S,  second- 
ary dentin ;  B,  bay-like  excavations  filled  with 
medullary  or  inflammatory  corpuscles ;  M,  mul- 
tinuelear  body ;  V,  blood-vessels  in  transverse 
section. 


ing  to  the  record,  was  not  exposed 
when  the  tooth  had  been  filled  five 
years  before,  but  which  was  found 
upon  removing  the  filling  not  only  ex- 
posed, but  the  pulp -chamber  was  en- 
larged to  more  than  twice  its  normal 
size.  This  case  occurred  in  a  lady 
aged  about  forty,  who  had  been  suffer- 
ing for  more  than  a  year  with  reflex 
neuralgia  and  dimness  of  vision  which 
threatened  blindness. 

Fig.  506  is  made  from  a  jDhotograph 
of  a  superior  central  incisor  in  the  pri- 
vate collection  of  the  writer,  and  shows 
the  pulp-chamber  greatly  enlarged. 

Bodecker  *  presents  a  figure  illustrating  the  resorption  of  secondary 
dentin  (Fig.  507),  which  seems  to  indicate  the  manner  in  which  resorption 
of  the  dentin  forming  the  walls  of  the  pulp-chamber  takes  place  in  this 
class  of  cases.  At  M  will  be  noted  a  large  multinucleated  cell  (giant 
cell)  which  has  invaded  the  area  of  resorption  and  is  evidently  performing 
the  function  of  the  odontoclasts  by  removing  the  dentin. 

Degenerative  inflammation  of  the  pulp,  involving  structural  changes  in  the 
tissues,  is  usually  caused  by  a  long-continued  and  low  form  of  inflamma- 
tion, such  as  would  be  likely  to  be  produced  by  a  pseudo-  or  by  an  incom- 
plete exposure  of  the  pulp,  or  by  a  pulp -capping.  The  most  common  form 
of  degeneration  of  structure  is  atrophy  of  all  the  normal  elements  of  the 
pulp  except  its  fibrous  tissue,  which  becomes  greatly  increased  in  amount, 
forming  areola  which  are  filled  with  fluid.  (Black.)  The  changes  in  the 
structure  usually  take  place  at  or  near  the  point  of  exposure,  but  they  are 
not  always  confined  to  this  location.  The  bulb  of  the  j)ulx3  suffers  most, 
while  the  balance  of  the  organ  may  appear  to  be  in  a  more  or  less  normal 
condition.  Fig.  508  illustrates  this  condition,  and  was  made  from  the  bul- 
bous end  of  the  pulp  of  a  tooth  which  was  the  subject  oi pyorrhoea  alveolaris. 


Morphology  and  Histology  of  the  Dental  Tissues,  p.  645. 


INFLAMMATION   OF   THE    DENTAL    PULP. 


415 


Black*  says  of  this  affection,  "The  original  cells  of  the  pulp  for  the 
most  part  disappear  or  lose  their  nuclei  and  become  converted  into  very- 
fine  fibres.  Areola  develop  in  the  matrix,  and  all  the  histologic  characters 
of  the  tissue  are  profoundly  changed." 


Fig.  508. 


jfes^ 


Section  of  dental  pulp.    Bulbous  end.    Fibrous  degeneration.     (V.A.Latham.)     X  50 


Arkovy  has  described  this  affection  as  reticular  atrophy  of  the  pulp. 
Black  found  in  his  studies  of  this  condition  every  possible  grade  of  change, 
from  an  occasional  appearance  of  areolse  to  complete  areolation  of  large 
portions  of  the  pulp.  He  thinks  it  is  possible  that  the  oedema  noticed  in 
the  affection  may  be  the  result  of  hypersemia  which  has  produced  effusion, 
and  yet  in  all  the  cases  examined  he  found  the  evidences  of  inflammatory 
action  unmistakable. 

The  symptomatology  is  not  well  marked,  although  the  sensitivity  of  the 
organ  is  greatly  diminished  to  all  the  tests  applied. 

Treatment. — The  only  treatment  that  can  be  recommended  is  devi- 
talization of  the  pulp  and  its  extirpation. 


American  Sj^stem  of  Dentistry,  vol.  i.  p.  859. 


CHAPTEE    XXV. 

EXPOSURE   OF   THE   DENTAL   PULP   AND   ITS   TREATMENT. 

Exposures  of  the  dental  pulp  are  either  the  result  of  caries  or  of  trau- 
matic injuries  of  an  accidental  nature  which  produce  a  loss  of  tissue  by 
fracture,  thus  uncovering  the  pulp,  or  as  a  result  of  surgical  injury  in  the 
preparation  of  the  cavity  to  receive  a  filling. 

Deep-seated  caries  is  the  most  common  cause  of  exposure  of  the  pulp. 
By  the  processes  of  decalcification  and  disintegration  of  the  dentin  it 
sooner  or  later  exposes  the  pulp  and  renders  it  subject  to  painful  irritation, 
hypersemia,  inflammation,  and  finally  devitalization. 

In  the  consideration  of  the  subject  of  pulp  exposure  from  caries  and 
traumatic  injuries  it  may,  for  the  convenience  of  description,  be  divided 
into  three  stages  or  degrees, — viz.  : 

Pseudo-exposure. 

Incomplete  exposure. 

Complete  exposure. 

Pseudo-exposure,  or  false  exposure  of  the  pulp,  is  that  condition  which 
prevails  when  the  carious  process  has  so  far  progressed  as  to  have  nearly 
reached  the  pulp,  leaving  only  a  thin  layer  of  partially  decalcified  and 
infected  dentin  to  protect  it  from  mechanical  injury,  but  which  is,  how- 
ever, more  or  less  readily  penetrated  by  the  oral  secretions,  the  bacteria  of 
the  mouth,  the  soluble  chemic  substances  which  enter  the  mouth  in  the 
form  of  food,  condiments,  and  medicines,  and  by  the  influence  of  changes 
of  temperature  of  even  a  moderate  degree. 

These  irritating  influences  often  render  the  pulp  highly  sensitive,  and 
cause  it  to  respond  verj^  acutely  whenever  they  are  brought  to  bear  upon 
it  through  the  carious  cavity,  while  if  prolonged,  they  end,  sooner  or  later, 
in  inflammation  and  finally  death  of  the  pulp. 

A  traumatic  injury  which  nearly  exposes  the  pulp,  leaving  the  pro- 
tecting surface  so  thin  as  to  cause  the  pulp  to  respond  painfully  to  the 
above-mentioned  irritating  agencies,  should  be  classed  as  a  pseudo- 
exposure. 

The  pain  which  is  produced  by  active  hypersemia  is  generally  acute  and 
paroxysmal  in  character,  but,  as  a  rule,  is  only  of  a  few  minutes'  duration. 
It  comes  on  most  frequently  while  eating,  especially  sweets  and  acid  fruits, 
or  drinking  hot  or  very  cold  fluids,  or  breathing  very  cold  air.  If  the 
pulp  becomes  infected  with  the  i^yogenic  organisms,  efforts  to  conserve  its 
vitality  will  usually  prove  futile. 

Treatment. — Two  methods  may  be  employed  in  the  treatment  of 
pseudo-exposure  of  the  pulp, — viz.,  conservation  and  devitalizotioyi. 

Conservation. — Conservative  treatment  of  the  pulp  should  in  these 
cases  be  employed  under  all  circumstances  which  present  a  fair  prospect  of 
416 


EXPOSURE    OF   THE   DENTAL    PULP    AND    ITS   TREATMENT.  417 

maintaining  the  organ  in  a  normal  condition.  The  pulp  being  the  organ 
which  supplies  nutrition  and  sensation  to  the  dentin,  its  vitality  should  for 
these  reasons  be  carefully  preserved,  while,  upon  the  other  hand,  after  the 
vitality  of  the  pulp  has  been  destroyed,  the  tooth  loses  its  translucency,  be- 
comes more  or  less  discolored  and  brittle,  presents  a  greater  susceptibility 
to  caries,  and  is  liable  to  periodic  attacks  of  pericemental  irritation  from  the 
decomposition  of  the  organic  elements  of  the  dentin,  while  occasionally  the 
pericemental  irritation  may  increase  in  severity  or  become  chronic,  resulting 
finally  in  the  loss  of  the  tooth.  It  therefore  becomes  for  the  latter  reasons 
also  very  important  that  the  vitality  of  the  pulp  should  be  preserved 
whenever  it  is  possible  to  do  so.  Certain  operators  have,  on  the  other 
hand,  advocated  the  conservation  of  the  pulp  in  all  cases.  Witzel  advo- 
cates conservative  treatment  of  even  small  portions  of  the  living  pulp  re- 
maining in  the  canals,  and  Belisario  and  Henry  advocate  the  same  course. 

Devitalization  should  be  practised  only  as  a  dernier  ressort  The  writer 
is  aware  that  this  teacJiing  is  in  opposition  to  some  very  good  authorities, 
who  have  frequently  stated  "that  when  a  tooth  has  been  fully  formed  it 
has  no  further  need  of  the  pulp,  and  it  may,  therefore,  be  destroyed  with- 
out damage  to  the  integrity  of  the  tooth  ;"  but  he,  nevertheless,  desires  in 
these  pages  to  enter  a  protest  against  such  teaching,  and  against  the  prac- 
tice of  destroying  by  wholesale  dental  pulps  which  he  believes  could,  with 
the  same  degree  of  care  and  skill  exercised  in  their  devitalization,  have 
been  preserved  to  fulfil  their  normal  function  for  many  years,  or  even  for  a 
lifetime. 

Opening  the  Cavity. — In  the  opening  of  the  cavity  and  the  excava- 
tion of  the  disintegrated  dentin  great  care  should  be  exercised  not  to 
expose  the  pulp.  The  relations  of  the  pulp-chamber  and  of  its  cornua 
must  be  kept  constantly  in  mind,  and  even  then  it  may  be  that  by  an  un- 
lucky sweep  of  the  excavator  or  an  excessive  prolongation  of  the  pulp 
cornua  the  pulp -chamber  may  be  entered  and  the  difiiculties  of  the  con- 
servation of  the  pulp  thereby  greatly  increased. 

After  all  of  the  disintegrated  and  decalcified  tissue  has  been  removed 
— and  this  should  not  be  commenced,  for  prudential  reasons,  until  the 
rubber  dam  has  been  adjusted — the  cavity  may  be  carefully  wiped  with  an 
efiacient  antiseptic,  like  the  oil  of  cloves,  oil  of  cassia,  oil  of  peppermint,  or 
carbolic  acid,  ninety-five  per  cent.  The  surface  of  the  cavity  lying  nearest 
to  the  pulp  should  then  be  carefully  scrutinized  with  a  magnifying  lens  for 
the  slightest  exposure  of  the  pulp  or  of  its  cornua,  and  if  the  integrity  of 
the  pulp-chamber  is  found  to  be  intact,  the  pulp  may  be  protected  from 
pressure  and  thermal  shock  by  the  interposition  of  a  rigid  and  non-con- 
ducting material — that  will  possess  no  irritating  qualities — between  the 
bottom  of  the  cavity  and  the  filling. 

Temperature  Sense. — The  "temperature  sense,"  as  shown  by  Dr. 
Louis  Jack,*  varies  greatly  in  different  individuals,  and  this  fact  must 
always  be  taken  into  consideration  in  all  efforts  of  conservative  treatment 
of  the  pulp. 


*  Dental  Cosmos,  January,  1899. 

27 


418  OPERATIVE   DENTISTRY. 

Dr.  Jack  has  found  tliat  the  variation  in  the  heat- rate  stands,  in  normal 
teeth,  between  120°  and  135°  F.,  while  the  normal  cold-rate  varies 
between  40°  and  70°  F. 

The  teeth  of  each  person  seem  to  possess  an  individual  tolerance  of  a 
certain  degree  of  heat  and  cold  which  will  not  produce  pain,  but  whenever 
these  limits  are  passed  pain  is  the  result.  The  average  range  of  tolerance 
was  found  to  vary  between  forty-eight  and  seventy-five  degrees.  It  there- 
fore becomes  evident  that  if  the  vitality  of  the  pulp  is  to  be  preserved  in 
this  class  of  carious  teeth  the  pulp  must  be  thoroughly  protected  against 
any  degree  of  temperature  that  might  cause  irritation. 

Dr.  Jack  also  observed  that  marked  intolerance  to  degrees  of  tempera- 
ture that  are  within  the  average  normal  range  indicated  a  serious  condi- 
tion of  the  pulp,  and  that  after  the  pulp  had  been  protected  for  a  time 
from  thermal  shock,  the  temperature  range  gradually  increases  until 
normal  tolerance  is  reached. 

Materials  for  Capping. — Gutta-percha  is,  perhaps,  by  reason  of  its 
non-conducting  qualities,  the  very  best  material  that  can  be  used  for  the 
purpose  of  protecting  the  pulp  against  thermal  shock.  The  cavity  may  be 
entirely  filled  with  it,  or  it  may  be  used  as  a  simple  non-conducting  lining, 
and  the  balance  of  the  cavity  filled  with  zinc  oxyj)hosphate  cement. 
Metal  fillings  should  never  be  introduced  into  such  cavities  until  the  normal 
tolerance  to  heat  and  cold  have  been  restored.  The  metallic  filling  may  be 
inserted  after  removing  a  portion  of  the  gutta-percha  or  cement.  Its  entire 
removal  and  substitution  of  a  metal  filling  often  proves  disastrous  to  the 
vitality  of  the  pulp.  Such  teeth  can  be  made,  however,  more  comfortable 
by  the  insertion  of  porcelain  inlays  than  by  metallic  fillings,  as  the  porce- 
lain is  a  poorer  conductor  of  caloric  than  the  metals. 

Zinc  oxy sulphate  cement  to  which  a  drop  or  two  of  oil  of  cloves  has 
been  added  is  frequently  used  as  a  capping  or  protector  of  the  dental 
pulp  because  of  its  non- irritating  and  non-conducting  proiDerties. 

Whenever  the  layer  of  dentin  covering  the  pulp  is  very  thin  and  there 
is  danger  of  producing  pressure  upon  it  in  packing  the  filling,  or  from  the 
pressure  of  mastication,  a  metallic  cap  may  be  employed  (Fig.  509),  or  one 

may  be  fashioned  from  sheet  lead  or  tin.  The 
^^'       '  metal   should  be    so   concaved    that  when  it  is 


^)  ^  "Pl  H  1|)  p  U  placed  in  position  in  the  cavity  it  will  touch  only 
at  its  edge.  To  protect  the  pulp  from  thermal 
shock  and  to  secure  the  cap  in  position  thick  zinc  oxysulphate  may  be 
flowed  upon  the  bottom  of  the  cavity,  the  cai)  placed  in  this  and  covered 
with  a  layer  of  the  same  material  or  of  gutta-percha  stopping, — after  the 
cement  has  set, — and  the  balance  of  the  cavity  filled  with  zinc  oxyphos- 
phate. 

Zinc  oxychloride  cement  is  sometimes  used  as  a  pnlp  capping,  but  the 
dangers  of  irritation  and  devitalization  due  to  the  irritating  and  escharotic 
action  of  the  zinc  chloride  has  caused  it  to  be  looked  upon  as  an  unsafe 
material  to  employ  when  the  conservation  of  the  pulp  is  the  object  in 
view.  It  was  formerly  employed  to  a  considerable  extent  not  only  in  the 
treatment  of  such  cases  as  are  now  under  consideration,  but  in  cases  of 


EXPOSURE    OP   THE    DENTAL    PULP   AND    ITS    TREATMENT.  419 

actual  or  complete  exposure  of  tlie  pulp,  and  statements  were  made  by 
enthusiastic  o^Derators  as  to  its  wonderful  conserving  effect  upon  the  pulp  ; 
but  a  few  years  later  it  was  discovered  that  the  term  preserving  better 
suited  the  condition  which  resulted  from  its  application  as  a  pulp  capping, 
for  nearly  all  the  cases  which  had  been  so  treated  were  found  to  be  in  a 
devitalized  and  mummified  condition. 

As  an  obtundent  of  hypersensitive  dentin  in  shallow  cavities  it  is  of 
great  value  ;  but  its  application  to  deep-seated  caries,  or  where  the  pulp  is 
almost  exposed,  its  use  is  to  be  deprecated  for  the  reasons  given  above. 

Zinc  oxyphosphate  cement  is  employed  by  some  operators  to  the  exclusion 
of  all  other  materials  for  capping  the  pulp  in  this  class  of  cases.  To  pre- 
vent the  irritation  and  pain  which  would  follow  its  direct  application  to 
the  dentin  various  substances  are  used  to  line  the  cavity, — viz.,  solutions 
of  chlora-percha,  varnishes,  Canada  balsam,  and  zinc  sulphate. 

As  a  further  protection  against  thermal  shock  the  bottom  of  the  cavity 
may  be  covered  with  a  disk  of  sheet  asbestos,  blotting-paper,  writing-paper, 
horn,  quill,  cork,  vulcanite,  or  ivory,  which  may  be  secured  in  place  with 
chlora-percha,  copal  varnish,  or  Canada  balsam,  and  zinc  oxyphosphate 
flowed  over  it. 

Incomplete  Exposures  due  to  Caries. — Incomplete  exposure  of  the 
pulp  may  be  described  as  that  condition  in  which  a  single  cornu  or  horn 
of  the  pulp  is  exj)osed  as  the  result  of  caries  or  from  traumatic  injury. 
This  class  of  exposures  occurring  as  the  result  of  caries,  the  exposure  of 
recent  origin,  and  in  which  the  irritation  and  pain  have  not  been  mani- 
fested for  more  than  twenty-four  hours,  are  many  times  amenable  to  con- 
servative treatment. 

Exposures  of  this  class,  if  caused  by  traumatic  injury  during  the  ex- 
cavation of  the  cavity,  give  better  prospects  of  successful  conservation 
than  those  produced  by  caries,  for  the  reason  that  the  latter  are  generally 
more  or  less  infected  with  the  pyogenic  micro-organisms ;  while  in  the 
traumatic  cases,  if  treated  upon  surgical  principles,  infection  can  be  pre- 
vented and  the  pulp  maintained  in  a  normal  condition  by  the  exclusion  of 
the  micro-organisms  and  other  sources  of  irritation  and  protecting  it  from 
pressure. 

Symptoms. — Incomplete  exposure  of  the  pulp,  due  to  caj-ies,  some- 
times presents  a  history  of  intervals  of  irritation  and  pain,  more  or  less 
severe,  covering  a  period  of  a  few  hours  or  days.  Finally  the  patient  is 
robbed  of  a  night's  sleep  by  the  severity  of  the  pain,  and  next  morning 
seeks  professional  advice.  The  pain  is  described  as  sharp,  stinging,  or 
burning  in  character,  and  the  affected  tooth  is  exceedingly  sensitive  to 
heat  and  cold,  sweets  and  acids,  or  pressure  of  food  within  the  cavity. 
Paroxysms  of  pain  are  induced  by  contact  with  any  of  these  irritating  sub- 
stances, while  it  is  aggravated  by  vigorous  exercise,  by  lowering  the  head, 
as  in  stooping  to  pick  something  from  the  floor,  or  by  assuming  the  hori- 
zontal position.  Exercise  and  the  positions  mentioned  increase  arterial 
tension  in  the  head,  and  thus  by  the  increased  pressure  of  blood  in  the 
pulp,  pain  is  induced  or  augmented.  The  pain  in  the  early  stages  of  irrita- 
tion is  never  very  severe,  but  as  the  case  progresses  towards  inflammation 


420  OPERATIVE    DENTISTRY. 

it  becomes  more  and  more  intense,  with  shorter  intervals  of  respite,  until 
finally  the  pain  becomes  of  a  sharp,  deep-seated,  throbbing  character  and 
well-nigh  continuous,  which  denotes  a  high  degree  of  congestion.  These 
symptoms  are  doubtless  due,  in  a  majority  of  instances,  to  septic  infection 
from  the  pyogenic  bacteria  found  in  the  oral  secretions  and  food  debris 
lodged  in  the  mouth  and  between  the  teeth.  With  proper  treatment  fol- 
lowing antiseptic  lines  even  a  case  of  this  character  is  not  entirely  beyond 
hope  of  successful  conservation,  provided,  as  already  mentioned,  these 
symptoms  have  not  been  manifest  more  than  twenty-four  hours. 

Treatment. — The  treatment  consists,  first,  of  efforts  to  allay  the  pain 
by  removing  the  causes  of  irritation  and  subduing  the  hypersemia,  and 
secondly,  of  protecting  the  pulp  against  the  further  influence  of  these  exciting 
causes  of  incipient  inflammation. 

The  cavity  should  first  be  carefully  syringed  with  tepid  water  to 
which  has  been  added  a  little  soda  bicarbonate  and  an  antiseptic  like 
listerine,  pasteurine,  or  borolyptol,  to  remove  the  food  debris,  neutralize 
the  acid  condition,  and  correct  to  a  certain  degree  the  septic  condition. 
Many  times  this  procedure  will  relieve  the  severity  of  the  pain  in  a  few 
minutes,  or  entirely  control  it.  The  rubber  dam  should  then  be  adjusted, 
the  cavity  carefully  dried  with  bibulous  paper  or  amadou,  and  the  carious 
matter  deftly  removed,  care  being  exercised  not  to  wound  the  pulp,  as  such 
wound  would  endanger  the  vitality  of  the  pulp  by  furnishing  an  open  gate- 
way for  the  entrance  of  the  pyogenic  bacteria  to  its  deeper  structures. 

If  the  pulp  is  accidentally  wounded,  the  bleeding  point  should  be 
touched  with  oil  of  cloves  or  other  eflicient  but  non-escharotic  antiseptic. 
The  walls  of  the  cavity  may  now  be  saturated  with  oil  of  cloves,  oil  of 
cassia,  or  the  volatile  extract  of  eucalyptus,  and  the  exposed  cornu  of  the 
pulp  protected  with  a  metal  cap  or  other  suitable  rigid  covering,  the  con- 
cavity of  which  has  been  filled  with  a  paste  composed  of  oil  of  cloves  and 
zinc  oxide,  or  zinc  oxysulphate  cement.  The  object  of  the  paste  or  the 
cement  is  twofold, — first,  to  furnish  an  antiseptic  dressing  for  the  exposed 
crown  of  the  pulp,  and  secondly,  to  seal  the  perforation  of  the  pulp-chamber 
with  a  non-irritating  substance,  which  would  effectually  prevent  any  pro- 
trusion of  the  pulp  beyond  its  normal  limits. 

Over  the  cap  should  now  be  flowed  a  thick  solution  of  chlora-percha 
or  zinc  oxysulphate,  and  after  this  has  set  the  cavity  may  be  filled  with 
gutta-percha  stopping  or  zinc  oxyphosphate. 

Prognosis. — The  prognosis  in  these  cases  will  depend  upon  the  local 
condition  of  the  pulj)  when  capped,  the  surgical  care  with  which  the 
cavity  has  been  prepared  and  sterilized,  the  dexterity  with  which  the 
antiseptic  dressing  has  been  applied,  the  methods  used  to  prevent  pressure 
upon  the  exposed  portion  of  the  pulp,  the  i^rotection  afforded  against 
thermal  shock  by  the  overlying  filling-material,  and  the  constitutional 
condition  of  the  patient  at  the  time  of  the  operation  and  for  some  months 
thereafter. 

If  the  inflammatory  symptoms  have  not  passed  beyond  the  stage  of 
hypersemia — and  this  may  be  known  by  the  character  and  duration  of  the 
pain  as  already  indicated — and  the  surgical  and  antiseptic  technique  has 


EXPOSURE    OF    THE    DENTAL    PULP    AND    ITS   TREATMENT.  421 

been  carefully  carried  out,  the  prognosis  will  be  fairly  favorable,  provided 
the  health  of  the  patient  is  good  at  the  time  of  the  operation  and  so  con- 
tinues. Anaemic  conditions,  plethora,  pregnancy,  nervous  debility,  tuber- 
culosis, and  syphilis  are  contraindications  for  the  conservative  treatment 
of  the  pulp. 

It  must  be  remembered,  however,  that  whatever  form  of  capping  is 
employed  to  conserve  the  vitality  of  the  pulp,  its  ultimate  success  as  an 
operation  depends  upon  the  formation  of  secondary  dentin  at  the  point 
of  injury  which  shall  remove  the  dangers  of  the  devitalization  of  the  pulp 
caused  by  the  disease  or  the  injury,  and  this  cannot  be  assured  until  after 
the  lapse  of  a  considerable  period  of  time,  usually  from  one  to  two  or 
three  years. 

Although  it  is  true  that  a  large  proportion  of  these  cases  will  do  well 
under  favorable  circumstances,  yet  it  is  equally  true  that  at  the  end  of  this 
time  a  certain  number  will  be  found  to  have  lost  their  vitality,  even  though 
little  discomfort  or  none  at  all  had  been  experienced. 

Incomplete  Exposures  of  the  Pulp  due  to  Traumatism. — Trau- 
matic incomplete  exposures  of  the  pulp  are  usually  the  result  of  accidents 
during  the  excavation  of  a  carious  cavity,  or  from  mechanic  abrasions  or 
chemic  erosions,  but  occasionally  it  may  occur  from  an  external  injury 
which  fractures  a  portion  of  the  crown  and  leaves  one  of  the  cornua 
exposed. 

In  traumatic  exposures  of  the  pulp  due  to  accidents  in  excavating,  the 
cornu  of  the  pulp  is  usually  wounded,  and  is  followed  by  hemorrhage  and 
acute  x)ain,  which,  however,  soon  subsides.  The  bleeding  ]3oint  may  be 
treated  as  just  described,  or  irrigated  with  a  five  per  cent,  warm  solution 
of  carbolic  acid,— escharotics  should  be  avoided, — and  as  soon  as  hemor- 
rhage has  ceased  the  extent  of  the  injury  can  be  ascertained,  when,  if  it  does 
not  extend  beyond  the  involvement  of  the  cornu  of  the  pulp  or  a  very 
small  opening  into  the  chamber,  the  excavation  may  be  completed  and  the 
case  treated  by  capping  upon  the  lines  already  indicated.  If,  however,  the 
pulp  has  been  seriously  wounded  by  the  instrument  slipping  into  the  bul- 
bous portion  and  causing  a  complete  exposure,  devitalization  is  the  only 
remedy. 

In  exposures  due  to  abrasions,  erosions,  and  external  traumatisms  which 
fracture  the  crown,  conservative  treatment  is  out  of  the  question,  as 
there  is  no  means  of  adequately  protecting  the  pulp  against  the  irritating 
influences  which  surround  it.  Devitalization  or  immediate  extirpation 
must  therefore  be  resorted  to  in  order  to  relieve  the  patient  of  the  suffer- 
ing incident  to  an  exposure  of  this  character. 

SECONDARY   DENTIN,    OR   DENTIN   OF   REPAIR. 

One  of  the  main  objects  sought  in  the  conservative  treatment  of  the 
exposed  pulp  is  to  stimulate  nature  to  repair  the  breach  made  in  the  walls 
of  the  pulp-chamber  by  disease  or  traumatism,  or  to  protect  the  pulp 
against  a  threatened  breach  of  its  walls  by  the  interposition  of  a  new- 
formed  tissue  laid  down  by  the  odontoblasts.  In  the  study  of  the  forma- 
tion and  calcification  of  the  dentin  (Chapter  II.)  it  has  been  shown  that  the 


422  OPERATIVE    DENTISTRY. 

chief  function  of  the  odontoblasts,  which  are  arranged  in  a  continuous 
layer  over  the  entire  periphery  of  the  pulp,  was  that  of  forming  or  build- 
ing the  dentin,  and  that  upon  the  completion  of  the  formative  process  the 
function  ceased. 

The  function,  however,  of  the  formative  cells  is  not  lost,  for  it  fre- 
quently happens  that  under  the  stimulation  of  irritation  occurring  at  any 
period  of  life,  produced  by  mechanic  abrasion,  chemic  erosion,  caries,  and 
other  forms  of  external  irritation,  the  odontoblasts  again  become  active 
and  deposit  calcific  material  within  the  dentinal  tubuli,  termed  tubular 
calcification,  or  lay  down  at  the  point  of  irritation  a  x)eculiar  calcific  mate- 
rial, termed  secondary  dentin,  the  dentin  of  repair  of  Salter,  in  a  seeming 
effort  to  build  a  barrier  against  the  encroachment  of  the  disease  or  injury 
upon  the  territory  of  the  pulp  (Fig.  510).  These  deposits  are  always  found 
opj)Osite,  or  rather  at  the  base  of,  the  dentinal  fibrillse  involved  in  the 
irritation.  Calcific  material  is  also  laid  down  by  the  odontoblasts  in  tem- 
porary teeth  retained  beyond  their  normal  period,  and  as  a  senile  condition 
in  the  teeth  of  elderly  people  (Fig.  511),  the  pulp-chamber  and  canal  being 
sometimes  almost  obliterated  by  this  process. 

Secondary  dentin  has  sometimes  a  very  close  resemblance  to  normal 
dentin,  but  it  is  by  no  means  a  perfect  example  of  this  structure.  In  the 
new  formation  as  found  in  i^ersistent  temporary  teeth,  in  the  senile'  calcifi- 
cation of  elderly  persons,  and  in  cases  of  chronic  irritation,  the  new-formed 
tissue  often  approaches  the  perfection  in  structure  of  normal  dentin,  while 
in  those  cases  which  are  dependent  upon  some  form  of  external  irritation 
like  mechanic  abrasion,  chemic  erosion,  or  caries,  the  new-formed  tissue 
which  has  been  developed  to  shield  the  pulp  against  these  irritating  influ- 
ences often  presents  a  low  grade  of  structural  organization,  the  tubules 
being  scanty,  very  irregular  in  their  course,  and  the  tissues  more  dense 
than  normal  dentin,  while  occasionally  it  will  be  almost  structureless. 

Dr.  Black*  is  of  the  opinion  that  the  formation  of  secondary  deposits 
within  the  pulp-chamber,  in  cases  of  exposed  pulps  which  have  been 
capped,  do  not  permanently  conserve  the  vitalitj^  or  the  health  of  the  pulj), 
but  that  they  usually  produce  exhaustion,  degeneration,  and  finally  death 
of  the  organ. 

He  looks  upon  those  cases  of  capping  as  the  most  hopeful  which  have 
passed  on  for  years  without  the  formation  of  any  deposit  whatever,  very 
many  of  which  seem  to  remain  indefinitely  in  a  perfectly  healthy  con- 
dition. 

Dr.  Truman  f  says  new  formations  are  usually  expected  from  capping 
pulps ;  but  this  expectation  is  rarely  i-ealized,  as  here  the  irritation  is 
excessive  and  becomes  a  destructive  force. 

Complete  exposure  of  the  pulp  is  that  condition  in  which  the  inva- 
sion of  caries  has  penetrated  the  pulp-chamber  and  laid  bare,  to  a  greater 
or  less  extent,  the  body  or  bulbous  portion  of  the  pulp,  or  a  traumatic 
injury  has  caused  the  loss  of  a  sufficient  amount  of  the  crown  to  open  the 
pulp-chamber  and  expose  its  vital  contents.     Complete  exposures  of  the 

*  American  System  of  Dentistry.  t  Ibid. 


Secondarj-  dentin 


;Cnamel 


Dentin 


Fig.  510.— Vertical  section  of  human  cuspid,  showing  formation  of  secondary  dentin  in  the  coronal 
portion  of  the  pulp-chamber  as  a  result  of  loss  of  tissue  at  the  morsal  edge.     ;<  100. 


j^namel 


Secondary  dentin 


Dentin 


Fig.  511.— Vertical  section  of  human  central  incisor,  showing  formation  of  secondary  dentin  in  the 


EXPOSURE    OF   THE    DENTAL    PULP   AND    ITS    TREATMENT.  423 

pulp,  due  to  caries,  are  rarely  amenable  to  conservative  treatment  by- 
reason  of  the  inflammatory  symptoms  which  are  always  present.  These 
symptoms  may  be  acute  or  chronic  in  their  character.  When  the  symptoms 
are  acute  and  the  opening  into  the  pulp-chamber  is  small,  so  that  the  pulp 
is  confined  within  the  pulp-chamber,  the  swelling  which  takes  i)lace  causes 
pressure  upon  the  blood-vessels,  which  results  in  stasis,  general  infarction, 
and  death, — gangrene  of  the  organ.  If,  on  the  other  hand,  the  opening 
into  the  pulp-chamber  is  large,  so  that  the  pulp  in  swelling  finds  relief 
from  the  pressure  by  a  portion  of  its  congested  tissue  escaping  through 
the  opening  into  the  cavity  of  decay,  stasis  and  infarction  are  sometimes 
avoided,  and  the  inflammatory  symptoms  assume  a  low  form  or  chronic 
type.  In  either  case  devitalization  of  the  pulp  is  the  only  satisfactory 
method  to  pursue,  as  eflbrts  to  conserve  its  vitality  usually  prove  futile. 
Traumatic  exposures  of  a  like  character  are  likewise  not  amenable  to  con- 
servative treatment,  and  in  all  such  cases  the  pulp  should  be  extirpated 
by  the  immediate  method  under  local  or  general  anaesthesia. 

DEVITALIZATION   AND   EXTIRPATION   OF   THE   PULP. 

Three  general  methods  are  emj)loyed  for  the  devitalization  and  extirpa- 
tion of  the  dental  pulp  :  first,  by  the  cliemic  action  of  drugs ;  second,  by 
instrumentation ;  and  third,  by  local  or  general  ancesthesia. 

The  drugs  which  have  been  used  for  devitalizing  the  pulp  by  means  of 
their  chemic  action  are  arsenous  acid,  zinc  chloride,  cobalt  (arsenical  ore), 
caustic  potassa,  and  chromic  acid. 

The  requirements  of  a  devitalizing  agent  are, — 

1.  That  it  act  painlessly. 

2.  That  it  destroy  vitality  promptly. 

3.  That  the  action  of  the  drug  shall  not  produce  discoloration  of  the 
dentin. 

Devitalization  of  the  pulp  is  generally  accomplished  by  the  application 
of  arsenous  acid  (arsenic  trioxide),  which  destroys  the  vitality  of  the  organ 
en  masse.  No  other  remedy  used  for  this  purpose  possesses  the  above 
requirements  in  so  large  a  degree,  or  is  so  prompt,  certain,  and  complete 
in  its  devitalizing  effect  upon  the  dental  pulp ;  and  yet,  as  the  result  of 
accident  or  in  careless  hands,  it  is  capable  of  doing  great  damage  to  the 
surrounding  tissues,  and  on  this  account  some  oi)erators  who  have  wit- 
nessed its  destructive  effects  upon  the  gingival  tissues  and  the  alveolar 
processes  have  discarded  its  use  altogether.  It  still,  however,  remains  the 
^'sheet-anchor"  of  the  profession  for  this  purpose  despite  the  ill  effects 
which  sometimes  follow  its  use. 

Arsenic  trioxide  was  first  introduced  for  the  purpose  of  devitalizing 
the  dental  pulp  by  Si30oner  (1836),  and  when  employed  with  proper  care 
there  is  no  remedy  which  gives  such  universally  good  results.  Arsenic 
trioxide  is  usually  combined  with  acetate  of  morphine  in  various  propor- 
tions, and  creosote,  carbolic  acid,  and  oil  of  cloves,  or  other  essential  oil, 
added  to  form  a  creamy  paste. 

The  earliest  combination  of  this  character  was  the  formula  of  Dr.  J^ 
D.  White  (1855)  : 


424  OPERATIVE    DENTISTRY. 

R     Arsenous  acid, 

Morphiai  sulph.,  iia  gr.  x  to  xv  ; 
Carbolic  acid,  q.  s.  ft.  paste. 

A  later  formula  is  that  of  Dr.  J.  Foster  Flagg  (1877)  : 

R     Arsenous  acid,  gr.  v  ; 
Morphise  acetas,  gr.  x  ; 
01.  caryophylli,  q.  s.  ft.  paste. 

A  more  recent  combination  substitutes  cocaine  hydroclorate  for  the 

morphine  : 

R     Arsenous  acid,  gr.  x  ; 

Cocainse  hydrochl.,  gr.  xx  ; 
01.  cinnamomi,  q.  s.  ft.  paste. 

Miller  (1894)  recommended  the  following  formula  as  possessing  advan- 
tages over  those  containing  morphine,  as  the  thymol  which  is  substituted 
for  the  morphine  exceeds  it  in  its  local  anaesthetic  action,  and  has  the 
decided  advantage  of  possessing  a  considerable  antiseptic  quality  : 

R     Thymol, 

Arsenous  acid,  aii  gr.  x  ; 

01.  caryophylli,  q.  s.  ft.  paste. 

Morphine. — The  object  in  adding  this  drug  to  the  paste  is  to  utilize 
its  narcotic  properties  to  relieve  the  severity  of  the  pain,  which  is  often 
induced  by  the  irritating  effect  of  the  arsenic  upon  the  tissues  of  the  pulp. 

Carbolic  acid  (deliquesced  crystals)  is  a  notable  escharotic,  while  it  also 
possesses  antiseptic  and  local  anaesthetic  or  analgesic  properties,  which 
make  it  a  valuable  ingredient  of  a  devitalizing  paste.  Carbolic  acid  alone 
is  capable  of  devitalizing  the  pulp. 

Creosote  is  not  so  vigorous  an  escharotic  as  carbolic  acid,  while  it  pos- 
sesses about  the  same  degree  of  antiseptic  and  local  anaesthetic  power. 

Oil  of  cloves  is  but  very  slightly  escharotic,  while  its  antiseptic  and 
local  obtunding  effect  is  very  considerable. 

Cocaine  liydrocMorate  is  substituted  for  the  morphine  because  it  possesses 
such  strong  local  anaesthetic  powers. 

Oil  of  ciimamon  is  added  for  its  antiseptic  qualities. 

Thymol  is  used  for  its  local  anaesthetic  and  antiseptic  action. 

Chloretone  is  also  used  for  its  local  anaesthetic  effects,  and  is  preferred  by 
some  operators  to  cocaine,  as  it  is  non-poisonous.  (See  chapter  on  anaes- 
thesia. ) 

PHYSICAL   EFFECTS   OF   ARSENIC   UPON   THE   PULP. 

The  application  of  arsenic  trioxide  to  the  living  pulp  produces  certain 
definite  phenomena  which  are  irritative  in  their  character,  and  represent 
the  earlier  physical  phenomena  of  acute  inflammation, — viz.,  arterial 
hyperaemia,  pain,  increasing  from  a  low  grumbling,  gnawing  character  to 
acute,  violent  paroxysms,  followed  by  acute  congestion  of  the  blood-ves- 
sels,  exudation,  and  finally  apical   strangulation,   or  general  infarction, 


EXPOSURE  OF  THE  DENTAL  PULP  AND  ITS  TREATMENT.      425 

which  effectually  prevents  egress  or  ingress  of  the  blood-stream,  causing 
complete  stasis  and  death  of  the  organ.  Fig.  512  is  made  from  a  section  of 
a  pulp  which  had  been  treated  with  arsenic,  and  shows  the  congestion  and 
enlargement  of  the  blood-vessels. 

Fig.  512. 


Section  of  dental  pulp.    Blood-vessels  congested  from  application  of  arsenic. 

Flagg*  describes  the  phenomena  as  follows  :  '' A  minute  portion  of  the 
arsenic  being  introduced  into  the  circulation  of  the  pulp  acts  as  a  dy- 
namic, vital  irritant,  which  causes,  first^  a  determination  of  blood  to  the 
organ,  resulting,  in  from  fifteen  to  twenty  minutes,  in  uneasiness  and  throb- 
bing pain  ;  secondly,  congestion,  which  causes  a  cessation  of  the  throbbing 
character  of  the  pain  ;  thirdly^  usually,  complete  cessation  of  pain,  leaving 
like  the  going  down  of  a  wave  ;  this  condition  has  a  varied  length  of  dura- 
tion, dependent  upon  the  extent  and  frequency  of  the  previous  pulp  irri- 
tation, extent  of  pulp  exi)osure,  temperamental  impressibility, — nervous 
irritability, — systemic  ability  to  resist  and  react, — vital  resistance, — and  such 
like  considerations.  The  death  of  the  pulp  en  masse  being  due  to  strangu- 
lation of  the  vessels  at  the  apex  in  consequence  of  the  congestion." 

Animal  tissue  when  thoroughly  impregnated  with  arsenic  trioxide,  even 
in  small  amount,  is  rendered  proof  against  putrefaction,  but  dental  pulps 
which  have  been  devitalized  by  this  drug  are  only  very  exceptionally  ren- 
dered proof  against  the  putrefactive  process.  Arsenic  in  large  quantity, 
locally  applied,  is  an  energetic  and  powerful  escharotic  or  caustic,  but  its 
action  is  somewhat  slow  as  compared  with  carbolic  acid,  zinc  chloride, 
caustic  potassa,  and  chromic  acid.  Its  escharotic  effect  is  more  marked  and 
rapid  upon  tissues  of  low  vitality — abnormal  growths — than  upon  normal 
tissue.     Absorption,  however,  takes  place  much  more  rapidly  in  healthy 

*  J.  Foster  Flagg,  Dental  Cosmos,  July,  1877. 


426  OPERATIVE    DENTISTRY. 

than  in  highly  inflamed  or  dead  tissue.  This  fact  explains  why,  in  com- 
paratively healthy  puli)s,  devitalization  with  arsenic  is  so  much  more  rapid 
and  effective  than  in  those  which  are  inflamed,  partially  calcified,  or  other- 
wise diseased.  In  the  former  a  single  application  is  usually  all  that  is 
necessary  to  eflect  complete  devitalization,  while  in  the  latter  two,  three, 
and  even  four  applications  are  sometimes  required. 

Arsenic  when  used  in  large  quantities  ui^on  an  extensive  surface,  as  in 
the  treatment  of  cayicer  of  the  breast  and  lupus  in  which  the  application  has 
been  intentionally  permitted  to  include  surrounding  healthy  tissue,  absorp- 
tion of  the  drug  by  the  healthy  tissue  may  take  place — before  its  devital- 
izing action  renders  the  tissue  incapable  of  conveying  it  to  the  circula- 
tion— in  such  quantities  as  to  x^roduce  constitutional  effects  or  endanger 
life.  That  such  a  condition  could  be  possible  as  a  result  of  pulp-devital- 
ization  seems  beyond  the  possibilities  of  peradventure,  while,  upon  the 
other  hand,  irritation  of  the  apical  space  or  the  tissues  beyond,  resulting 
from  the  application  of  an  arsenical  dressing  to  a  vital  pulp  in  other  than 
deciduous  teeth,  and  in  the  permanent  teeth  of  young  children  before  the 
completion  of  calcification  of  the  roots  in  which  the  foramina  are  very 
large,  could  only  occur,  if  intelligently  used,  as  a  rare  and  accidental 
circumstance. 

The  violent  irritating  action  of  arsenic  when  coming  in  contact  with 
the  surface  of  the  pulp  immediately  causes  arterial  hyperaemia,  while  the 
devitalizing  effect  produced  upon  the  tissue  lying  in  immediate  contact 
with  it  renders  the  devitalized  tissue  incapable  of  absorbing  the  drug, 
and  thus  prevents  it  being  carried  into  the  circulation  except  in  an 
infinitesimal  quantity,  too  small  to  provoke  irritative  inflammation  at  the 
apical  space. 

Flagg,*  in  experiments  instituted  by  him  to  ascertain  the  amount  of 
arsenic  absorbed  by  the  pulp,  found  it  ' '  almost  incomprehensively  minute, 
never  more  than  one  millionth  (!)  of  a  grain."  He  further  maintains  that 
the  apical  irritation  which  often  follows  upon  the  fourth  to  the  seventh 
day  after  arsenical  devitalization  is  not  due  to  the  effects  of  arsenic  which 
has  passed  to  the  apical  foramen,  but  to  inflammatory  conditions  extend- 
ing to  the  apical  portion  of  the  pulp,  and  are  the  last  stages  of  the  process 
of  devitalization,  as  may  be  readily  shown  by  microscopic  examination 
of  the  apical  extremity  of  a  pulp  removed  at  this  time,  and  which  is 
further  proved  by  the  subsidence  of  the  pericemental  symptoms  in  a  few 
hourSj  or  at  most  in  twenty-four  to  forty-eight  hours. 

Arkovy  presented  an  elaborate  study  of  the  action  of  arsenic  upon  the 
dental  pulp  at  the  International  Medical  Congress,  1881,  which  may  be 
briefly  summarized  as  follows :  arsenic  trioxide  (As.^03)  when  applied 
to  a  vital  dental  pulp  induces  : 

'^1.  Hypersemia,  partial  or  complete,  depending  upon  the  amount  of 
the  drug  used  ;  expansion  of  the  blood-vessels,  with  a  tendency  to  throm- 
bosis and  capillary  embolism. 

"2.  It  does  not  produce  coagulation  of  the  tissue. 

*  Dental  Cosmos,  July,  1877. 


EXPOSURE    OF    THE    DENTAL    PULP    AND    ITS    TREATMENT.  427 

"3.  It  seems  to  possess  a  specific  influence  upon  the  blood-corpuscles, 
combining  with  the  haemoglobin  to  form  a  compound  of  arsen-hsemoglobin, 
which  produces  a  yellowish  tinge  of  the  pulp-tissue  and  affects  the  color 
of  the  blood. 

"4.  The  drug  is  conveyed  in  substantia  into  the  blood-channels,  where 
it  produces,  besides  the  changes  already  mentioned,  disintegration  of  their 
contents — granular  detritus — -and  shrinkage  or  ansemic  collapse  of  the  ves- 
sel walls.     This  being  most  noticeable  where  large  doses  had  been  used. 

"5.  The  connective-tissue  fibres  and  the  odontoblasts  undergo  no 
change,  but  the  connective-tissue  cells  are  increased  from  three  to  four 
times  their  normal  size. 

"6.  The  effects  upon  the  neurilemma  is  to  somewhat  increase  the  num- 
ber of  its  nuclei,  while  in  the  axial  part  granular  destruction  of  the  myelin 
sets  in  and  the  axis-cylinder  begins  in  various  locations  to  disappear  ; 
while  in  others  the  notchy  tumefaction  of  the  axis-cylinder,  usually  seen 
only  in  cases  of  central  lesion,  can  be  plainly  made  out. 

^'7.  These  alterations  are  found  scattered  throughout  normal-looking 
tissue. 

"8.  The  pulp,  in  whole  or  in  part,  and  the  neighboring  dentin  and 
cementum,  are  tinged  a  brownish  red  when  large  doses  of  the  drug  are  em- 
ployed. This  discoloration  is  most  marked  in  the  pulp  at  the  top  of  the 
bulbous  portion  and  at  the  apical  fourth  or  third." 

Miller  in  experimenting  upon  the  tails  of  mice  found  that  ''the  action 
of  the  arsenic  apjDcared  to  be  somewhat  accelerated  when  a  glass  ring  was 
applied  close  to  the  root  of  the  tail.  This  was  done  to  simulate  the  sur- 
roundings of  the  apical  vessels.  In  more  than  forty  cases  there  was  not 
one  in  which  the  action  of  the  arsenic  extended  beyond  the  ring,  and  the 
action  was  not  appreciably  affected  by  enclosing  the  tails  in  plaster  casts. 
The  action  of  the  arsenic  is  of  a  progressive  nature,  beginning  at  the  point 
of  application  and  extending  gradually  in  each  direction." 

Miller  denies  that  arsenic  trioxide  produces  escharotic  effects  upon  the 
pulp  like  that  of  zinc  chloride  or  carbolic  acid,  etc.,  and  states,  "The 
local  application  produces  no  immediate  visible  eff'ect  whatever." 

Method  of  Application. — In  the  ajDplication  of  arsenic  for  the  de- 
struction of  the  vital  pulp  certain  important  considerations  are  presented. 

1.  Dosage. — The  amount  of  the  drug  that  may  be  safely  applied  is 
from  one-sixteenth  of  a  grain  (0.001  gramme),  or  from  that  to  one-thirtieth 
of  a  grain  (0.002  gramme).  The  writer  has  found,  however,  in  his  expe- 
rience, that  one-hundredth  of  a  grain  (0.0006  gramme)  was  just  as 
effective  as  a  larger  amount,  provided  it  was  permitted  to  remain  in  con- 
tact with  the  pulp  for  from  three  days  to  one  week.  The  larger  the  dose 
the  quicker  the  death,  and  vice  versa,  but  the  large  dose  is  usually  very 
painful,  while  the  small  dose  will  devitalize  with  absolutely  no  pain  at  all. 

The  one-hundredth  part  of  a  grain  is  an  exceedingly  small  quan- 
tity, and  yet  it  can  be  approximated  as  readily  as  the  one-sixteenth  of  a 
grain  after  the  actual  amount  has  once  been  weighed  out  and  observed. 
The  approximate  amount  is  all  that  is  aimed  at,  for  no  one  would  think  it 
necessary  to  weigh  out  each  dose  to  be  applied. 


428  '  OPERATIVE    DENTISTRY. 

For  many  years  the  writer  has  not  used  morphine,  cocaine,  or  other 
obtunding  drug,  except  carbolic  acid,  in  combination  with  arsenic  for  de- 
vitalizing the  pulp,  and  has  found  it  exceedingly  rare  that  pain  has  been 
produced  by  the  application,  or  that  he  has  failed  to  painlessly  remove  the 
pulp  at  the  end  of  a  week  or  ten  days.  The  exceptions  have  been  cases 
in  which  severe  irritation  and  hypersemia  were  present  before  the  applica- 
tion was  made.  The  text-books  usually  warn  the  student  not  to  use  any 
coagulating  drug  in  combination  with  arsenic,  as  the  coagulum  X3revents  the 
arsenic  from  taking  effect.  Clinical  experience  upon  the  part  o'f  the  writer 
does  not  substantiate  this  teaching. 

2.  Placing  the  Dressing. — The  cavity  should  first  be  syringed  with 
tepid  water  containing  an  antiseptic  or  an  alkali  like  soda  bicarbonate. 
Next  the  rubber  dam  should  be  adjusted, — and  this  is  wise  in  all  cases 
before  making  an  application  of  arsenic, — the  cavity  carefully  dried,  and 
the  dressing,  which  should  be  composed  of  a  piece  of  cotton  the  size  of  a 
pin-head,  may  be  moistened  with  ninety-five  per  cent,  carbolic  acid,  and 
the  dry  arsenic,  which  has  been  previously  measured  out,  gathered  up 
with  the  moistened  dressing  and  then  laid  carefully  over  the  point  of  ex- 
posure. 

A  somewhat  larger  dose  is  necessary  in  cases  of  pseudo-exposure,  as 
the  drug  is  slow  in  penetrating  the  dentin  even  though  completely  decal- 
cified. 

3.  Sealing  the  Cavity. — It  has  been  customary  to  seal  the  cavity  con- 
taining an  arsenical  dressing  with  cotton  and  sandarach  or  with  tempo- 
rary stopping.  Neither  of  these  materials  are  really  suitable  for  the  pur- 
pose, as  the  first  soon  gets  foul  and  very  offensive,  while  from  swelling 
of  the  cotton  fibre  or  compression  from  the  force  of  mastication  painful 
pressure  upon  the  pulp  is  induced.  The  temporary  stop5)ing  is  also  liable, 
especially  in  crown  cavities,  to  be  compressed  by  mastication  and  produce 
painful  j)ressure  upon  the  pulp  ;  while  both  of  them  are  open  to  the  seri- 
ous objection  of  forming  leaky  stoppings,  which,  if  employed  in  approxi- 
mal,  labial,  or  buccal  cavities  extending  beneath  the  gum,  might  lead  to  the 
escape  of  a  portion  of  the  arsenic  and  destruction  of  the  soft  tissues  and 
alveolar  j)rocess  immediately  surrounding  the  tooth.  Zinc  oxyphosphate 
mixed  to  a  creamy  paste  and  introduced  so  as  to  avoid  pressure  is  the  only 
safe  material  with  which  to  seal  a  cavity  containing  an  arsenical  dressing. 
If  this  material  were  universallj^  used  for  this  purpose,  sloughing  of  the 
gum,  necrosis  of  the  alveolus,  and  loss  of  the  tooth,  as  a  result  of  the 
escape  of  the  arsenic,  would  become,  except  in  rare  cases  due  to  accidental 
causes,  a  bygone  experience. 

In  those  cases  which  give  evidence,  by  pain,  of  considerable  hypersemia, 
palliative  treatment  should  first  be  employed  to  relieve  the  suffering  and 
reduce  the  congested  state  of  the  pulp-vessels,  as  by  this  means  devitaliza- 
tion may  be  rendered  more  sure  and  at  the  same  time  nearly  if  not  quite 
painless.  The  cavity  should  first  be  disinfected  with  a  tepid  carbolic  acid 
solution — two  per  cent. — or  a  solution  of  fonnol,  two  to  five  per  cent. 

Pormol  is  composed  of  forty  volumes  of  formaldehyde  and  sixty  of 
water.     The  former  X3er  cent,  is  made  by  adding  one  volume  of  formol  to 


EXPOSURE   OF   THE    DENTAL    PULP    AND    ITS    TREATMENT.  429 

nineteen  volumes  of  water,  the  latter  by  adding  one  volume  of  formol  to 
seven  volumes  of  water. 

Formol  owes  its  value  as  a  disinfectant  to  its  great  diffusibility  in  the 
strengths  above  mentioned  ;  it,  however,  possesses  coagulating  power. 

The  application  of  formol  to  an  exposed  pulp  is  at  first  slightly  painful, 
but  this  immediately  passes  away  and  the  effect  is  eminently  soothing. 

The  pulp  may  now  be  dressed  with  morphine  and  one  of  the  essential 
oils,  and  the  cavity  sealed  for  several  days  with  temporary  stopping  or  zinc 
oxyphosphate ;  the  latter  being  preferable  from  the  fact  that  pressure  is 
avoided  and  the  pulp  given  complete  protection  against  all  external  irri- 
tating agencies. 

Some  operators  prefer  to  dress  the  pulp  with  cocaine  hydrochlorate  and 
oil  of  cinnamon. 

Pulps  which  have  been  exposed  for  some  time  usually  show  evidences 
of  suppuration.  These  cases  should  be  treated  by  first  removing  as  much 
as  possible  of  the  decalcified  dentin  around  the  exposure  as  can  be  done 
without  producing  much  pain,  and  carefully  syringing  the  cavity  to  remove 
the  debris  and  wash  away  the  pus.  The  arsenical  dressing  should  be  placed 
in  direct  contact  with  the  pulp  and  sealed  in  by  the  method  above  described. 

After  the  arsenical  dressing  has  been  removed,  it  is  well  to  follow 
this  treatment  with  a  dressing  of  tannic  acid  for  a  few  days,  as  the  tannin 
hardens  the  pulp  and  facilitates  its  removal. 

Dr.  Harlan  has  recommended  swabbing  the  cavity  with  the  sesquioxide 
of  iron,  as  this  unites  with  the  arsenic,  forming  an  insoluble  compound, 
and  thus  prevents  any  further  action  of  this  agent.  Sesquioxide  of  iron 
(ferric  hydrate,  Fe2(HO)6)  is  made  by  precipitating  ferric  sulphate  or  ferric 
chloride  by  adding  ammonia  or  sodium  hydrate.  The  precipitate  should 
be  allowed  to  drain  on  muslin  for  a  few  minutes.  The  soft  mass  or  magma 
should  be  placed  in  the  cavity  of  the  tooth.  In  local  poisoning  from 
arsenic  the  magma  should  also  be  placed  over  the  inflamed  gum  as  well  as 
in  the  cavity  of  the  tooth. 

Occasionally  a  small  fragment  of  living  pulp  will  be  left  in  the  apical 
portion  of  the  canal,  which  is  still  very  sensitive.  It  is  better  to  destroy 
this  by  repeated  applications  of  ninety-five  per  cent,  carbolic  acid  than  to 
reapply  arsenic,  for  fear  of  it  going  beyond  the  apical  foramen.  Danger 
also  exists  of  mistaking  an  enlarged  apical  foramen  for  a  piece  of  vital 
pulp  remaining  in  the  canal. 

Errors  of  this  character  have  been  made  by  some  of  the  very  best  and  most 
careful  practitioners.  In  all  such  cases  it  is  better  to  err  upon  the  safe  side 
rather  than  to  cause  the  loss  of  a  tooth  by  a  careless  or  mistaken  diagnosis. 

Discoloration  of  the  Dentin. — This  condition  often  follows  a  violent 
congestion  of  the  pulp,  which  has  been  caused  by  external  irritants.  The 
discoloration  is  produced  by  the  disorganization  of  the  blood-corpuscles  and 
the  distribution  of  the  haemoglobin  through  the  dentinal  tubuli.  Arsenic 
applied  in  large  quantity  for  the  devitalization  of  the  pulp  usually  pro- 
duces a  violent  congestion,  and  more  often  results  in  producing  discolora- 
tion of  the  dentin  than  when  the  drug  is  used  in  small  quantities. 

It  is  therefore  important  in  all  cases  of  highly  congested   pulps  to 


430 


OPERATIVE    DBKTISTRY. 


Fig.  513. 


relieve  this  coudition  by  palliative  treatment  or  local  depletion  before 
ajiplying  tlie  arsenic. 

Devitalization  of  the  pulp  with  arsenic  will  rarely  result  in  this  un- 
fortunate condition  if  the  above  precautions  are  taken  and  the  amount  of 
arsenic  used  does  not  much  exceed  one-hundredth  part  of  a  grain. 

Extirpation  of  the  Pulp. — The  devitalized  pulp  should  be  removed  at 
the  end  of  a  week  or  ten  days  after  the  application  of  the  arsenical  dressing, 
for  the  reason  that  at  this  time  it  can  be  done  without  pain  or  hemorrhage, 
as  the  natural  process  of  separation  or  exfoliation  has  taken  place  between 
the  dead  and  the  living  tissues  at  the  apex  of  the  root.  If  it  is  allowed  to 
remain  much  beyond  this  period,  pericemental  irritation  is  likely  to  follow 
as  a  result  of  putrefactive  decomposition  and  local  septic  poisoning. 

The  removal  of  the  dead  pulp-tissue  may  be  accomplished  by  first 
thoroughly  opening  the  pulp-chamber  with  burs  or  excavators  upon  lines, 
which  will  give  the  most  direct  access,  and 
then  passing  a  fine  barbed  broach  (Fig.  513) 
to  the  apex  of  the  canal,  rotating  it  once  or 
twice  in  the  same  direction,  and  upon  with- 
drawing it  the  pulp  will  be  found  entangled 
upon  the  barbs  of  the  broach.  If,  however, 
the  tissue  of  the  pulp  has  been  softened  by 
decomposition  and  does  not  come  away  with 
the  instrument,  it  must  be  broken  up  and 
removed  by  constant  rotation  of  the  broach, 
or  fibres  of  cotton  may  be  wrapped  upon  a 
plain  Swiss  jeweller's  broach  and  rotated  in 
the  canal.  This  is  the  very  best  method  of 
removing  the  remains  of  a  pulp  which  has 
become  liquefied  by  decomposition. 

The  writer  has  sometimes  adopted  a  method  that  was  advo- 
cated in  the  journals  several  years  ago  (1872  or  1874)  for 
removing  pulp  debris  which  could  not  be  extracted  with  the 
broach, — viz.,  the  introduction  into  the  pulp-cavity  and  canals 
of  pure  pepsin  dissolved  in  water  acidulated  with  hydrochloric 
acid,  1  to  250,  and  carried  into  them  by  the  means  of  fibres  of 
cotton  which  had  been  saturated  in  the  solution.  This  was 
sealed  into  the  tooth  with  gutta-percha  or  zinc  oxyphosphate 
and  allowed  to  remain  for  twenty-four  hours.  The  object  of 
this  method  was  to  digest  the  remnants  of  the  pulp  and  render 
them  fluid,  so  that  they  could  be  washed  out  by  irrigation  or 
removed  by  absorbent  cotton  wound  upon  a  broach.  The  result 
of  such  treatment  is  not  only  the  removal  of  the  pulp  debris, 
but  it  also  sweetens  the  canals  and  completely  removes  the  odor 
of  decomposition. 

If  the  pulp  is  extirpated  at  the  end  of  a  week  or  ten  days 
after  devitalization  it  will  come  away  entire  to  the  very  apex 
of  each  canal,  leaving  these  channels  clean  and  in  a  fit  condition  to  be 
immediately  filled. 


ft 


' 


y 


Barbed  nerve- 
broaches. 


DHAPTEE   XXYI. 

PULPLESS   TEETH   AND    FILLING   PULP- CANALS. 

Definition. — A  tooth  which  contains  a  devitalized  x^ulp  is  said  to  be 
dead ;  a  better  term  to  designate  this  condition  is  pulpless,  for  the  reason 
that  the  tooth  cannot  be  correctly  designated  as  dead  so  long  as  it  main- 
tains a  vital  connection  through  its  pericementum  with  the  alveolus  of  the ' 
jaw  ;  but  when  this  membrane  has  lost  its  vitality  or  has  been  destroyed, 
the  tooth  may  then  be  correctly  termed  dead  or  necrosed,  for  it  has  no 
further  vital  connection  with  the  economy. 

All  devitalized  or  pulpless  teeth  may  be  classed,  from  the  surgical 
stand-point,  under  two  heads,— viz.,  aseptic  and  septic.  Inasmuch  as  the 
septic  cases  are  the  most  common  they  will  be  considered  first. 

Septic  pulp-canals  are  those  which  are  invaded  by  the  xDyogenic  and 
saprophytic  micro-organisms,  and  contain  decomposing  or  XDutrefying  tissue 
in  greater  or  less  quantity,  food  debris,  the  fluids  of  the  mouth,  or  other 
material  which  forms  a  suitable  soil  for  the  growth  and  propagation  of  this 
class  of  organisms.     (See  Chapter  V.) 

Devitalization  of  the  pulp  is  usually  the  result  of  caries  and  exj)osure 
of  this  organ,  followed  by  septic  infection,  inflammation,  and  suppuration  ; 
consequently  the  great  majority  of  the  cases  of  jjulpless  teeth  which  are 
presented  for  treatment  are  in  a  septic  condition.  Another  class  of  septic 
cases  are  those  in  which  the  pulp  of  a  perfectly  sound  tooth  has  lost  its 
vitality  from  some  traumatic  injury  or  from  embolism,  but  which  perhaps 
for  months  or  years  thereafter  has  given  no  evidence  of  its  condition 
except  by  the  change  in  the  color  of  the  tooth.  Suddenly,  however,  symp- 
toms of  a  septic  inflammation  of  the  pericemental  membrane  become  un- 
mistakably manifest ;  and  as  there  is  no  external  communication  with  the 
devitalized  ]3ulp  through  a  carious  cavity  by  which  the  infection  could 
have  entered  from  the  outside,  it  is  fair  to  presume  that  the  organisms 
which  have  established  the  suppurative  process  found  a  lodgement  at  the 
apical  space,  having  been  brought  there  through  the  avenues  of  the  circu- 
lation. On  the  other  hand,  teeth  of  this  class,  when  opened  for  the  purpose 
of  removing  the  dead  and  mummified  pulp,  often  take  on  the  most  violent 
septic  inflammation  as  the  result  of  the  admission  of  pathogenic  organisms 
from  the  atmosphere  or  the  fluids  of  the  mouth.  In  all  such  cases  the 
greatest  care  should  be  taken  to  prevent  septic  inflammation  by  the  use  of 
the  rubber  dam,  and  keeping  the  cavity  through  which  the  puliD-chamber 
is  to  be  reached  flooded  with  a  strong  antiseptic,  like  carbolic  acid  (ninety- 
five  per  cent.)  or  a  sublimate  solution  (1  to  1000  or  1  to  500),  'so  that  when 
the  pulp-chamber  is  opened  an  antiseiDtic  of  sufiicient  strength  will  be 
carried  into  it  to  prevent  the  growth  and  propagations  of  the  micro- 
organisms. Devitalized  pulps  which  have  not  been  infected  either  from 
external  sources  or  through  the  avenues  of  the  circulation  dry  up  and 
become  mummified. 

431 


432  OPERATIVE    DENTISTRY. 

The  sequelae  of  septic  infection  of  devitalized  pulps  are  pericementitis, 
dento-alveolar  abscess,  septiccemia,  and  j^yfemia. 

Pulpless  teeth  which  present  septic  canals  are  rarely  ever  entirely  free 
from  a  certain  amount  of  pericemental  irritation,  which  is  due  to  the  toxic 
effect  of  the  ptomaines  developed  from  the  action  of  the  micro-organisms 
upon  the  gangrenous  pulp,  and  which  has  been  forced  into  the  apical  space 
by  the  pressure  of  gases,  gravity,  or  by  instrumentation. 

If  the  organisms  which  have  attacked  the  gangrenous  pulp  are  of  viru- 
lent type,  active  inflammation  of  the  pericementum  and  alveolar  abscess 
are  likely  to  follow.  The  severity  of  the  inflammatory  symptoms  is  gov- 
erned in  j)art  by  the  character  of  the  infecting  organisms,  and  in  part  by 
the  local  resistance  of  the  tissues  and  the  diathesis  of  the  individual.  In 
those  persons  affected  with  tuberculosis  and  syphilis,  either  inherited  or 
acquired,  or  who  are  suffering  from  general  debility,  diabetes,  or  albu- 
minuria, inflammation  is  prone  to  run  a  rapid  and  severe  course. 

Aseptic  pulp  canals  are  those  in  which  for  various  reasons,  like  persist- 
ent hypersemia  due  to  caries,  abrasion,  or  fracture,  but  which  has  not 
exposed  the  pulp,  or  for  the  purposes  of  grafting  a  crown  or  setting  a 
bridge,  devitalization  of  the  pulp  by  the  application  of  arsenous  acid  has 
become  a  necessity.  The  removal,  under  antiseptic  precautions,  of  such 
pulj)S  as  soon  as  separation  or  sloughing  has  taken  place  at  the  apex 
leaves  the  canals  in  an  aseptic  condition,  and  no  other  treatment  is  re- 
quired than  that  of  filling  the  canals  at  the  same  sitting  and  before  the 
rubber  dam  is  removed.  The  septic  cases,  however,  often  require  several 
treatments  before  they  are  in  a  suitable  condition  to  warrant  the  filling  of 
the  canals  ;  in  fact,  this  should  never  be  done  while  there  is  any  mephitic 
odor  emitted  from  the  canals,  or  there  is  any  pericemental  soreness,  as 
these  are  unmistakable  evidences  that  septic  conditions  still  prevail.  Im- 
mediate root-filling  of  crooked  septic  canals  is  to  be  most  strongly  depre- 
cated, as  the  inevitable  result  is  an  alveolar  abscess. 

If,  however,  the  canals  can  be  rendered  aseptic  by  a  single  treatment, 
— and  this  is  i^ossible  in  some  cases,  as,  for  instance,  in  the  anterior  teeth 
when  the  canals  are  straight  and  of  large  size, — immediate  filling  of  the 
root  is  the  only  correct  practice.  Many  practitioners  make  the  mistake  of 
over-treating  such  cases,  thus  keeping  up  an  irritation  which  might  be 
avoided  by  sterilization  and  immediate  filling  of  the  root-canal. 

Preparation  and  Treatment  of  Pulp-Canals. — In  the  treatment  of 
septic  pulj)-canals  the  object  aimed  at  is  that  of  so  changing  the  condi- 
tions as  to  render  them  aseptic.  This  is  accomplished  by  first  excluding 
the  secretions  of  the  mouth  by  applying  the  rubber  dam  and  maintaining 
absolute  dryness  of  the  field  of  operation  in  all  subsequent  treatments. 
When  the  treatment  has  once  been  commenced,  from  that  time  onward 
to  the  completion  of  the  final  operation  the  secretions  of  the  mouth 
should  never  be  allowed  to  again  contaminate  the  pulp-canals.  Fail- 
ure to  observe  this  rule  often  renders  the  treatment  of  the  case  tedious 
and  unsatisfactory.  The  application  of  the  rubber  dam  as  the  first  step 
in  all  the  subsequent  treatments  is  the  only  way  to  insure  positive  aseptic 
conditions. 


Fig.  514. — Superior  left  cen- 
tral incisor.  Labio-lingual 
longitudinal  section,  showing 
pulp-canal. 


Fig.  51.5. — Superior  right  cen- 
tral incisor.  Mesio-distal  longi- 
tudinal section.  sho\ving  root- 
canal. 


Fig.  516.— Superior  left  lat- 
eral incisor.  Labio-lingual 
longitudinal  section,  showing 
root-canal. 


Fig.  517. — Superior  left  lat- 
eral incisor.  Mesio-distal  longi- 
tudinal section,  showing  root- 
canal. 


Fig.  518.— Inferior  left  cen- 
tral incisor.  Labio-lingual 
longitudinal  section,  showing 
root-canal. 


Fig.  519. — Inferior  right  cen- 
tral incisor.  Mesio-distal  longi- 
tudinal section,  showing  root- 
canal. 


Fig.  520.— Inferior  left  lat- 
eral incisor  Labio-lingual 
longitudinal  section,  showing 
root-canal. 


Fig.  521. — Inferior  right  lat- 
eral incisor.  Mesio-distal  longi- 
tudinal section,  showing  root- 
canal. 


Fig.  522. — Superior  right  cus- 
pid. Labio-lingual  longitudi- 
nal section,  showing  root- 
canal. 


Fig.  523. — Superior  left  cus- 
pid. Mesio-distal  longitudinal 
section,  showing  root-canal. 


Fig.  524.— Inferior  left  cuspid. 
Labio-lingual  longitudinal  sec- 
tion, showing  root-canal. 


Fig.  525. — Inferior  right  cus- 
pid. Mesio-distal  longitudinal 
section,  showing  root-canal. 


Fig.  526.— Peculiarities  in  inferior  cuspids  and  bicuspids.    A,  bifurcated  inferior  cuspid  ;  B,  bifurcated 
canal,  inferior  first  bicuspid  ;  C,  bifurcated  canal  (middle  third),  inferior  second  bicuspid. 


Fig.  527.— Superior  right  first 
bicuspid.  Bucco-lingual  longi- 
tudinal section,  showing  bifur- 
cation of  root  and  canals. 


Fig.  528.— Superior  left  first 
bicuspid.  Base  of  pulp-cham- 
ber, showing  entrance  to  root- 
canal. 


Fig.  529. — Superior  right  sec- 
ond bicuspid.  Bucco-lingual 
longitudinal  section,  showing 
root-canal. 


Fig.  530. — Superior  right  sec- 
ond bicuspid.  Base  of  pulp- 
chamber,  showing  entrance  to 
root-canal. 


Fig.  .531.— Inferior  right  first 
bicuspid.  Bucco-lingual  longi- 
tudinal section,  showing  root- 
canal. 


Fig.  532.— Inferior  left  first 
bicuspid.  Base  of  pulp-cham- 
ber, showing  entrance  to  root- 
canals. 


Fig.  533.— Inferior  right  sec- 
ond bicuspid.  Bucco-lingual 
longitudinal  section,  showing 
rootrcanal. 


Fig.  534. — Inferior  right  sec- 
ond bicuspid.  Base  of  pulp- 
chamber,  showing  entrance  to 
root-canal. 


PULPLESS   TEETH    AND    FILLING   PULP- CANALS.  433 

The  second  step  in  the  treatment  is  to  open  the  pulp-chamber  and  root- 
canals  and  remove  all  pulp  debris. 

This  is  a  simple  matter  in  the  superior  incisor  teeth,  which  have  straight 
roots  and  normal  canals,  as  shown  in  Figs.  514,  515,  516,  and  517,  which 
are  longitudinal  sections  cut  labio-lingually  and  mesio-distally. 

The  canals  of  the  inferior  incisor  teeth  are  more  difficult  to  enter,  by 
reason  of  the  mesio-distal  flattening  of  their  roots  and  the  corresponding 
narrowing  of  the  canals.  This  is  shown  in  Figs.  518,  519,  520,  and  521, 
sections  cut  in  the  same  manner  as  those  preceding. 

The  cuspids,  both  superior  and  inferior,  when  the  roots  are  straight,  are 
as  easily  entered  as  the  superior  central  incisors.  Figs.  522  and  523  are 
sections  of  the  superior  cuspids,  and  Figs.  521  and  525  are  sections  of  the 
inferior  cuspids.  Fig.  526  represents  some  of  the  peculiarities  met  with 
in  the  inferior  cuspids  and  bicuspids. 

The  superior  bicuspids  usually  offer  no  serious  difficulties  in  gaining 
access  to  their  canals.  It  must  be  remembered,  however,  that  the  superior 
first  bicuspid  has  usually  a  bifurcated  root  and  two  canals,  as  shown  in 
Fig.  527  ;  these  are  sometimes  very  small, — the  labial  root  being  the 
smallest, — and  for  that  reason  some  difficulty  may  be  experienced  in  fol- 
lowing them  to  the  apical  foramen.  Fig.  528  shows  the  location  of  the 
pulp-canals  at  the  base  of  the  pulp-chamber. 

The  superior  second  bicuspid  has  generally  a  single  root  and  a  single 
canal,  which  is  of  good  size,  as  shown  in  Fig.  529,  but  it  is  often  flattened 
mesio-distally.  Fig.  530  shows  the  form  and  size  of  the  pulp-canal  at  the 
base  of  the  pulp -chamber. 

The  inferior  bicuspids  are  almost  invariably  single-rooted  teeth,  having 
a  single  canal,  as  shown  in  Fig.  531,  which  usually  gives  free  access  to  the 
apex.  Fig.  532  shows  an  inferior  first  bicuspid  having  two  distinct  root- 
canals.  Their  position,  however,  is  sometimes  such — being  curved  inward — 
as  to  make  it  difficult  to  readily  open  the  canal,  except  with  drills  carried 
in  the  right-angle  hand-piece.  This  difficulty  is  more  often  experienced 
in  the  first  bicuspid  than  in  the  second.  Figs.  533  and  534  show  the  form 
of  the  canals  in  the  inferior  second  bicuspids. 

The  superior  molars  offer  somewhat  greater  difficulties  to  thorough  open- 
ing of  their  canals,  by  reason  of  the  angles  of  inclination  of  their  roots 
and  the  differences  in  the  size  of  the  roots  and  their  canals.  The  difficul- 
ties of  gaining  access  to  the  canals  increase  from  tooth  to  tooth  in  a  distal 
direction,  not  so  much  from  the  shape  and  direction  of  the  canals  as  from 
the  position  of  the  teeth,  which  makes  it  impossible  to  use  straight  instru- 
ments or  to  gain  a  view  of  the  field  of  operation  except  by  the  reflected 
image. 

In  the  superior  ^rs^  and  second  molars  the  disto-buccal  root  is  the  only 
one  which,  as  a  rule,  offers  any  considerable  difficulty  in  locating  and 
following  the  canal.  Fig.  535  is  a  longitudinal  section  of  the  disto-buccal 
and  lingual  roots  of  a  superior  first  molar,  and  Fig.  536  of  a  similar  tooth 
cut  so  as  to  show  the  buccal  roots.  This  canal  is  often  so  small  that  the 
finest  Donaldson  bristle  cannot  be  made  to  enter  it  for  more  than  a  small 
fraction  of  the  length  of  the  root.    Fig.  537  shows  the  size  and  form  of  these 

28 


434  OPERATIVE    DENTISTRY. 

canals  at  the  base  of  the  pulp-chamber.  The  pulp-canals  of  the  superior 
second  molars  are  shown  in  Figs.  538,  539,  and  540.  The  superior  third 
molars  are  the  most  difficult  to  treat,  but  this  is  due  more  to  their  position 
than  to  any  other  reason.  Fig.  544  is  a  longitudinal  section  of  the  mesio- 
buccal  and  lingual  root  of  a  superior  third  molar,  and  Fig.  542  of  the' 
buccal  roots  of  a  superior  third  molar.  Fig.  543  shows  the  size  and  form 
of  the  canals  at  the  base  of  the  pulp-chamber.  Fig.  544,  A  and  B,  presents 
abnormal  root-canals  sometimes  found  in  these  teeth. 

The  inferior  molars  when  the  canals  are  normal  present  no  difficulties, 
as  a  rule,  which  are  not  readily  overcome  by  a  little  skill  and  ingenuity. 
The  difficulties,  of  course,  are  increased  in  operating  upon  the  seco7id  and 
third  molars  over  those  of  the  first.  Fig.  545  shows  the  pulp-canals  in  a 
mesio-distal  longitudinal  section  of  an  inferior  first  molar.  Fig.  546  shows 
the  size  and  form  of  the  canals  at  the  base  of  the  pulp -chamber. 

It  should  be  borne  in  mind  that  the  roots  of  the  inferior  molars  are  con- 
siderably flattened  mesio-distally,  that  the  canals  are  constricted  in  the 
centre,  and  that  the  mesial  root  and  its  canal  are  usually  much  smaller  than 
the  distal  root  and  canal. 

Fig.  547  represents  a  mesio-distal  longitudinal  section  of  an  inferior 
second  molar,  and  Fig.  548  shows  the  size  and  form  of  the  canals  at  the 
base  of  the  pulp-chamber.  Fig.  549  represents  a  mesio-distal  longitudinal 
section  of  an  inferior  left  third  molar,  and  Fig.  550  shows  the  size  and  form 
of  the  canals  at  the  ball  of  the  pulp-chamber.  Fig.  544,  0,  illustrates  a 
not  uncommon  abnormality  of  the  root-canals  of  an  inferior  third  molar. 

The  abnormalities  in  the  number  and  the  form  of  the  roots  and  pulp- 
canals  are  so  many  and  so  varied  that  a  separate  description  of  them 
would  occupy  too  much  space  in  a  volume  of  this  character.  The  accom- 
panying illustrations.  Figs.  554,  552,  553,  554,  555,  556,  and  557,  and  Plate 
YII. ,  will,  however,  indicate  the  multiplicity  and  divergence  of  such  abnor- 
malities, and  will  be  a  guide  and  a  warning  to  the  student  that  he  will  en- 
counter an  uncertain  number  of  teeth  that  will  defy  all  efforts  to  follow 
their  j)ulp-canals  to  the  apex. 

Opening  the  Pulp-Chamber  and  Canals. — In  opening  the  pulp- 
chamber  and  the  root-canals  of  the  teeth  one  general  principle  should  be 
observed, — viz.,  to  obtain  access  to  the  pulp-chamher  in  a  direct  line  with  the 
axis  of  the  tooth.  This  rule  holds  good  for  any  tooth  in  any  part  of  the 
mouth.  The  operator  should  never  attempt  to  gain  access  to  the  pulp- 
canals  through  an  a-pproximal,  buccal,  or  lingual  cavity  of  decay  without 
extending  it  to  a  point  which  would  give  direct  access,  as  it  is  impossible 
to  thoroughly  cleanse  the  canals  or  properly  fill  them  through  cavities  of  de- 
cay in  these  locations  unless  the  above  rule  is  observed.  It  is  better  practice 
many  times  to  drill  an  opening  in  that  portion  of  the  tooth  which  will  give 
direct  access  to  the  pulp-canal,  treating  it  through  this  opening,  and  filling 
the  cavity  of  decay  without  reference  to  its  proximity  to  the  pulp-canal. 

The  superior  and  inferior  incisors  and  cuspids  should  always  be  opened 
through  the  lingual  surface,  as  this  gives  direct  access  to  the  canal,  while 
the  canals  of  the  bicuspids  and  molars,  both  superior  and  inferior,  should 
for  the  same  reason  be  opened  through  the  centre  of  the  morsal  surface. 


Disto-buccal 
root 


Lingual  root 


Fig.  535. — Superior  left  first  molar.  Bucco- 
lingual  longitudinal  section,  showing  root- 
canals. 


Mesio-buccal 
root 


Disto-buccal 
root 


Pig.  536. — Superior  left  first  molar.  Mesio- 
distal  longitudinal  section,  showing  buccal 
root-canals. 


Lingual  root 


Mesio-buccal 
root 

I  Disto-buccal 
root 


Fig.  537.— Superior  left  first  molar.  Base  of 
pulp-chamber,  showing  entrance  to  root- 
canals. 


Lingual  root 


Disto-buccal 
root 


Disto-buccal 

11 

root 

^fl 

Mesio-buccal 
root 


Fig.  538.— Superior  right  second  molar. 
Bucco-lingual  longitudinal  section,  showing 
rootrcanals. 


Fig.  539. — Superior  right  second  molar. 
Mesio-distal  longitudinal  section,  showing 
buccal  root-canal. 


lingual  root 


Mesio-buccal 
root 


Disto-buccal 
root 


Fig.  540.— Superior  left  second  molar.  Base 
of  puljvchamber,  showing  entrance  to  root- 
canals. 


Lingual  root 


M(  sio-buccal 
root 


Disto-buccal 
root 


Mesio-buccal 
root 


Fig.  541.— Superior  left  third  molar.  Bucco- 
lingual  longitudinal  section,  showing  root- 
canals. 


Fig.  542. — Superior  right  third  molar.  Mesio- 
distal  longitudinal  section,  showing  buccal 
root-canals. 


Disto-buccal 
root 


Mesio-buccal 
root 

Lingual  root 


Fig.  543.— Superior  right  third  molar.    Base  of  pulp-chamber, 
showing  entrance  to  root-canals. 


Fig.  544. — A,  superior  third  molar  ;  B,  superior  third  molar  ;  C,  inferior  third  molar 


Fig.  545.— Inferior  left  first 
molar.  Mesio-distal  longitu- 
dinal section,  showing  root- 
canals. 


Fig.  546. — Inferior  left  first 
molar.  Base  of  pulp-chamber, 
showing  entrance  to  root^ 
canals. 


Fig.  547. — Inferior  left  second 
molar.  Mesio-distal  longitu- 
dinal section,  showing  root- 
canals. 


Fig.  548. — Inferior  left  second 
molar.  Base  of  pulp-chamber, 
showing  entrance  to  root- 
canals. 


Fig.  549.— Inferior  left  third 
molar.  Mesio-distal  longitu- 
dinal section,  showing  root- 
canals. 


Fig.  550. — Inferior  left  third 
molar.  Base  of  pulp-cham- 
ber, showing  entrance  to  root- 
canals. 


Fig.  551. — A,  double-rooted  superior  lateral  incisor;   B.  united  superior  central  and  lateral  incisors; 
C,  superior  cuspid  ;  D,  double-rooted  superior  bicuspid. 


1 M ) 

] 

Fig.  552. — A,  D,  superior  cuspids ;  B,  C,  double-rooted  superior  cuspids ;  E.  multiple-rooted  superior 

bicuspid. 


Fig.  553. — Superior  bicuspids. 


1 

i 

Fig.  554.— Superior  bicuspid  and  molars. 


Fig.  555. — Inferior  first  bicuspids, 


Fig.  556. — Inferior  molars  and  bicuspids. 


Fig.  557. — Inferior  molars. 


PULPLESS    TEETH    AND    FILLING    PULP-CANALS. 


435 


Fig.  568. 
0 


Fig.  559. 


Fig.  560. 


Gates-Glidden 
drills. 


The  most  satisfactory  instrument  for  making  these  openings  is  the  spear- 
pointed  drill,  care  being  taken  not  to  drive  the  drill  beyond  the  floor  of 
the  pulp-chamber  in  those  teeth  which  have  multiple  roots,  as  by  so  doing 
it  might  penetrate  the  bifurcation.  In  the  superior  first  bicuspids  and  the 
molars  generally  this  opening  needs  to  be  considerably  enlarged  in  order 
to  enter  their  root-canals,  as  they  usually  form  divergent  angles  to  the  floor 
of  the  pulp-chamber.  This  enlargement  may  be  accomplished  with  cross- 
cut fissure  burs  or  cone  burs. 

Enlarging  the  Pulp-Canals.— The  question  of  the  propriety  of  me- 
chanically enlarging  the  pulp-canals  is  one  upon  which  there  is  a  consid- 
erable   difference    of    opinion. 
Some    operators    claim   that   a 
perfect  cleansing  of  the  canals 
cannot  be  accomplished  without 
it,  nor  the  canals  perfectly  filled 
except    by    such    preparation. 
Others  maintain  that  any  canal 
which  will  admit  a  Donaldson 
bristle  (Fig.   558)  can  be  per- 
fectly cleansed  without  enlarg- 
ing it,  and  those  cases  in  which 
the  canals  are  so  small  that  they 
will  not  permit  the  bristle  to 
enter  need  no  cleansing  orfilling. 
The  writer  prefers  a  middle  ground  be- 
tween these  two  extremes.     There  is  always 
danger  in  extremes,  both  of  theory  and  prac- 
tice ;  it  is,  therefore,  better  to  try  to  avoid  the 
errors  of  over-enthusiasm,  but  keep  so  alert 
for  the  truth  that  it  does  not  escape  us. 

Nearly  every  pulp- canal  that  will  permit 
the  passage  of  a  broach  or  a  Donaldson  bristle  is  placed  in 
better  condition  for  cleansing  and  filling  by  being  opened 
and  enlarged  with  a  reamer  or  Gates-Glidden  drill  (Fig. 
559)  for  at  least  a  part  of  its  extent ;  but  the  dangers  are 
so  great,  if  the  root  is  curved  or  very  much  flattened 
mesio-distally,  of  making  an  aperture  through  the  side  of 
the  root,  or  near  its  apex,  or  of  forcing  septic  material 
through  the  apical  foramen,  or  breaking  off  the  head  of 
the  drill  and  leaving  it  lodged  in  the  canal,  that  these  in- 
struments should  be  used  with  the  greatest  caution.  Break- 
ing the  drill  while  reaming  the  canal  is  much  more  liable 
to  occur  if  the  burring  engine  is  used  than  when  hand  in- 
struments are  employed.  Swiss  jewellers'  broaches  of  spring  temper  are 
very  valuable  instruments  for  enlarging  the  pulp-canals  and  cleansing  them 
of  debris,  and  are  much  less  liable  to  be  broken  and  lodged  in  the  canal 
than  any  other  form  of  instrument.  They  cut  much  slower  and  do  not  clog 
so  readily  as  the  Gates-Glidden  drill,  and  for  these  reasons,  in  small  and 


Donaldson 
Bristles. 


Donaldson      pulp- 
canal  cleansers. 


436 


OPERATIVE  DENTISTRY. 


constricted  canals  they  are  much  the  safest  instruments  to  use.    The  break- 
ing of  an  instrument  in  a  pulp-canal  is  an  exceedingly  vexatious  accident, 


Fig.  561. 

: 


-Drawn  temper. 


Fig.  562. 
Spring  temper.- 


Nerve  extractors. 


as  its  removal  often  entails  no  inconsiderable  amount  of  labor 
and  the  consumption  of  much  valuable  time. 

After  the  orifice  of  the  pulp-canal  has  been  sufficiently  en- 
larged to  suit  the  purpose,  it  should  be  thoroughly  cleansed  of  all 
debris  by  the  aid  of  the  Donaldson  pulp-canal  cleansers  (Fig. 
560)  or  the  nerve  extractors  shown  in  Figs.  561  and  562. 

Hydrochloric  and  suli3huric  acids  are  recommended  by  Calla- 
han and  others  for  chemically  enlarging  the  pulp-canals.  These 
agents  in  twenty-five  to  fifty  per  cent,  solutions  are  conveyed 
to  the  canals  upon  a  platinum  bristle  or  probe  and  carefully  in- 
sinuated. The  affinity  of  these  acids  for  the  lime-salts  is  such 
that  the  walls  of  the  canals  are  rapidly  softened  and  disinte- 
grated. The  softened  material  is  then  readily  removed  with  the 
Donaldson  pulp-canal  cleanser.  The  action  of  the  acid  may  be 
limited  by  saturating  the  canals  with  a  solution  of  sodium  bicar- 
bonate. 

The  third  step  in  the  operation  is  the  local  application  of  such 
therapeutic  agents  as  possess  germicidal,  antiseptic,  and  disinfect- 
ant properties.  These  agents  all  have  in  common  the  property 
of  destroying  pathogenic  and  saprophytic  micro-organisms,  pre- 
venting the  development  of  their  spores,  or  of  rendering  inert  or 
innocuous  their  waste  products.  They  differ,  however,  very 
markedly  in  other  respects  ;  for  instance,  some  of  them  coagulate 
albumin,  while  others  do  not.  The  former  are  therefore  classed 
as  coagulants,  the  latter  as  non-coagulants.  To  the  first  class  belong 
all  of  the  salts  of  metals  and  the  alcohols,  to  the  second  very 
many  of  the  essential  oils.  The  non-coagulants  possess,  in  a  great 
degree,  the  power  of  diffusion,  and  maintain  their  antiseptic 
properties  for  a  longer  period  than  the  coagulants  ;  hence  in  the 
treatment  of  pulpless  teeth  these  agents  are  considered  by  many 
operators  to  be  more  valuable  for  this  purpose  than  the  coagulants. 

The  metallic  salts,  which  possess  decided  germicidal  antiseptic  and  dis- 


Nerve 

extractor, 

with 

holder. 


PULPLESS   TEETH    AND    FILLING   PULP-CANALS.  437 

infectant  properties,  are  the  zinc  chloride  (ZnCl.^),  aluminum  chloride 
(AljClg),  mercuric  chloride  (HgCl2),  auric  chloride  (AUCI3),  sodium  sul- 
phite (Na^SOg),  cupric  sulphate  (CuSO^jSH^O),  and  the  argentic  nitrate 
(AgNOg) .  These  have  all  been  tested  as  germicidal  agents  in  the  treatment 
of  septic  pulp-canals,  but  all  except  the  zinc  and  aluminum  chlorides  and 
the  sodium  sulphite  have  been  discarded  on  account  of  the  discolorations 
which  they  produce. 

The  alcohols  which  are  commonly  employed  in  the  treatment  of  septic 
pulp-canals  are  the  ethylic  or  commercial  alcohol,  phenylic  alcohol, — viz., 
carbolic  acid, — and  creosote,  with  the  coal-tar  derivatives,  the  cresols. 

Formol  is  also  a  very  valuable  therapeutic  agent  for  disinfecting  septic 
pulp-canals.  The  forty  per  cent,  solution  is  reduced  to  a  solution  of  two 
to  three  per  cent,  for  dental  use.  Stronger  solutions  are  irritating  and 
coagulating. 

The  essential  oils  which  are  most  in  favor  for  the  treatment  of  septic 
conditions  of  the  pulp-canals  are  those  of  cloves,  cinnamon,  cassia,  thyme, 
and  eucalyptus.  They  are  not,  however,  so  powerful  in  their  germicidal 
action  as  the  coagulants. 

Certain  mineral  acids  have  also  been  recommended  for  this  purpose, — 
viz.,  the  hydrochloric  and  sulphuric  acids.  They  destroy  micro-organisms 
by  their  intense  chemic  action,  while  the  alkalies  which  have  been  employed 
are  a  combination  of  potassium  and  sodium, — Schreier's  alloy,  known 
under  the  name  of  kalium-natrium,  sodium  carbonate  (NajCOgjlOH^O), 
and  sodium  dioxide  (Na^O.^).  These  agents  act  by  saponifying  the  fatty 
matter  formed  by  the  decomposition  of  albuminous  substances  and  dissolv- 
ing the  albuminous  substances  contained  in  the  pulp-canal. 

Oxygen  and  chlorine  gases  in  the  nascent  state  have  also  been  employed 
for  the  purpose  of  rendering  the  pulp-canals  and  the  dentin  sterile.  Oxy- 
gen is  still  extensively  used.  These  agents  are  also  employed  for  the  pur- 
pose of  bleaching  discolored  teeth,  the  process  of  sterilization,  however, 
progressing  with  the  penetration  of  their  bleaching  action. 

Oxygen  gas  is  obtained  by  the  introduction  into  the  pulp-canals  of 
aqueous  and  etherial  solutions  of  hydrogen  dioxide  (HjOj)  or  solutions  of 
sodium  dioxide  (I^ajOJ.  These  agents  when  placed  in  contact  with  de- 
composing albuminous  substances  give  up  one  atom  of  their  oxygen ;  the 
liberated  oxygen  acting  as  an  oxidizer.  The  former  is  decomjDOsed  into 
water  and  nascent  oxygen,  the  latter  into  sodium  hydroxide  and  nascent 
oxygen. 

Chlorine  is  usually  employed  in  the  form  of  hypochlorites,  usually  in 
solutions  made  by  the  electrolytic  action  of  powerful  electric  currents  upon 
sea- water.    These  preparations  have  the  name  of  electrozone  and  meditrina. 

Iodine  and  bromine  and  their  preparations  are  also  powerful  sterilizing 
agents.  Iodine  is  usually  employed  in  the  form  of  the  tincture.  lodol 
and  iodoform  are  objectionable  for  use  about  the  mouth  on  account  of  their 
disagreeable  odor. 

Bromine  is  objectionable  for  the  same  reason,  and  also  for  its  intense 
irritating  effects. 

Aristol,  which  is  a  combination  of  thymol  and  iodine, — dithymol  binio- 


438  OPERATIVE  DENTISTRY, 

dide, — is  a  fovorite  remedy  with  many  operators  for  sterilizing  putrescent 
pulp-canals.  Hydronaplithol  and  a  number  of  similar  agents  have  been 
recommended  from  time  to  time,  and  have  been  used  with  considerable 
success. 

Authorities  differ  as  to  the  diffusibility  of  the  coagulants.  Some  have 
maintained,  notably  Harlan,*  that  zinc  chloride  and  carbolic  acid,  by 
their  coagulating  effect  upon  albumin,  did  not  become  diffused  through 
the  dentin ;  while,  upon  the  other  hand,  such  authorities  as  Truman,  f 
Kirk,  X  and  York  §  have  maintained  an  opposite  view. 

Formol  coagulates  albumin,  mucin,  and  gelatin,  the  coagulum  main- 
taining its  form  for  an  indefinite  period,  and  appears  to  be  rendered  per- 
manently sterile  so  far  as  the  action  of  the  organisms  of  decomposition  are 
concerned. 

MATERIALS   EMPLOYED   POR   FILLING   PULP-CANALS   AND   METHODS   OF 

INTRODUCTION. 

The  pulp-canals  having  been  properly  prepared  and  sterilized  are  now 
ready  for  the  introduction  of  the  material  which  is  to  occupy  the  space  in 
the  canals  formerly  held  by  the  dental  pulp.  The  main  object  sought  in 
filling  the  pulp -canal  is  to  hermetically  close  or  seal  the  apical  foramen, 
and  thus  to  prevent  the  egress  of  septic  material,  mephitic  gases,  micro- 
organisms, or  their  waste  products  from  the  canal  into  the  apical  space,  and 
also  to  preclude  the  possibility  of  the  entrance  by  transudation  of  fluids 
from  the  apical  tissues  into  the  canal.  These  materials  should  be  of  such  a 
character  that  they  will  remain  unchanged  by  any  influence  which  may  be 
brought  to  bear  upon  them  in  such  an  environment.  They  must  be  unirri- 
tating  to  the  soft  tissues,  impervious  to  moisture,  susceptible  of  such  ready 
adaptability  to  the  walls  of  the  canal  as  to  insure  a  moisture-tight  filling, 
and  should  possess  antiseptic  properties,  or  at  least  be  capable  of  being 
rendered  absolutely  sterile  when  introduced. 

The  materials  which  are  used  for  this  purpose  may  be  divided  into 
three  classes, — viz.,  solids,  plastics,  'dnd fluids.  These  materials  are,  however, 
often  combined,  the  solids  being  used  as  the  medium  whereby  the  x)lastic 
and  fl.uid  substances  are  introduced  into  the  canal.  The  solid  materials 
comprise  gold-foil  in  various  forms,  tin-foil  in  shreds  or  pellets,  gold  and 
copper  wire,  lead  and  wood  points,  the  latter  made  of  hickory  or  orange- 
wood  and  saturated  with  creosote. 

The  base  metals,  which  are  readily  oxidized,  have  never  been  extensively 
employed  on  account  of  their  liability  to  cause  discoloration  of  the  dentin, 
though  from  the  therapeutic  stand-point  this  quality  sometimes  renders 
them  very  valuable.  The  plastic  materials  which  are  most  commonly  em- 
ployed are  zinc  oxychloride  and  softened  gutta-percha  points.  Cotton, 
silk,  and  asbestos  fibre  are  sometimes  used  as  the  vehicle  for  introducing 
zinc  oxychloride  and  other  plastic  materials  into  the  pulp-canal.     The 

*  Dental  Eeview,  vol.  x.  p.  44. 

t  Proceedings  Academy  of  Stomatology,  Philadelphia,  1894. 

X  Dental  Cosmos,  vol.  xxxvi.  p.  181. 

§  Transactions  Illinois  State  Dental  Society,  1897. 


PULPLESS    TEETH    AND    FILLINa   PULP-CANALS. 


439 


objection  to  the  use  of  a  vegetable  fibre  like  cotton  as  a  filling  for  pulp- 
canals  is  overcome  when  it  is  emi)loyed  in  conjunction  with  the  zinc 
chloride,  "as  it  converts  the  cellulose  of  the  cotton  fibre  into  a  pectous 
substance  called  amyloid,  which  is  colorless  and  unchangeable  in  the 
conditions  existing  at  the  apex  of  a  pulp-canal."  * 

The  fluid  substances  used  for  this  purpose  are  gutta-percha — either  the 
red  base-]3late  or  the  white  stopping — dissolved  in  chloroform,  the  familiar 
chlora-percha,  and  salol,  and  paraffin.  The  two  latter  substances  are 
rendered  fluid  by  heat  before  being  introduced.  On  cooling  they  become 
hard. 

FiCx.  563. 


Fig.  564. 


Pulp-canal  pluggers. 

Gold-foil  was  the  first  material  used  for  the  i^urpose  of  filling  root- 
canals,  and  was  introduced  by  the  late  Dr.  Maynard,  of  Washington,  D.  C, 
about  the  year  1838.  His  raethod  was  to  use  narrow  strips  of  heavy  non- 
cohesive  foil,  and  to  pack  this  into  the  canal  with  delicate  pluggers  (Fig. 
563)  made  for  the  purpose.  When  skilfully  done  it  could 
be  made  to  hermetically  seal  the  apical  foramen,  but  its 
removal, if  circumstances  required,  was  well-nigh  impos- 
sible. For  many  years  the  older  operators  relied  entirely 
upon  this  method  of  filling  the  pulp-canal.  Tin  is  thought 
by  some  authorities  to  be  sux3erior  to  gold,  for  the  reasons 
that  it  is  more  easily  introduced  and  when  oxidized  pos- 
sesses antiseptic  properties. 

Dr.  W.  S.  How  recommended  the  use  of  shredded  tin 
for  sealing  the  apical  foramen.  To  avoid  the  danger  of 
forcing  the  tin  beyond  the  apical  foramen  a  series  of  fine 
probes  are  used  to  measure  the  depth  of  the  canal,  as 
shown  in  Fig.  564,  the  clutch  making  it  possible  to  meas- 
ure it  exactly.  With  these  probes  the  particles  of 
shredded  tin-foil  are  carried  to  the  apex  and  impacted 

into  position.  Canal  probe  gauge. 

This  method  is  open  to  the  same  objection  as  gold,  in 
that  it  cannot  be  removed  from  the  pulp-cavity.     The  advocates  of  this 
method  of  filling  pulp-canals  assert  that  this  objection  is  not  a  valid  one, 


Kirk,  American  Text-Book  of  Operative  Dentistry,  p.  325. 


440  OPERATIVE    DENTISTRY. 

for  if  the  canal  lias  been  properly  prei)ared  and  sterilized  and  tlie  material 
skilfnlly  introdnced  snch  a  necessitj'^  never  arises. 

Gold,  copper,  and  lead  points  are  made  by  shaping  sections  of  these 
metals  to  fit  the  caliber  of  the  canal,  the  right  length  being  ascertained  by 
measuring  the  depth  of  the  canal  with  a  suitable  probe  or  pulp- canal 
bristle.  The  late  Dr.  W.  H.  Morrison,  of  St.  Louis,  was  the  first  to  sug- 
gest the  use  of  gold  points  for  filling  pulp-canals,  which  he  recommended 
should  be  made  from  very  soft  pure  gold  wire  shaped  to  fit  the  canal  and 
of  such  length  as  not  to  pass  the  apical  foramen  when  driven  home.  When 
introduced  in  conjunction  with  the  plastic  or  fluid  materials  used  for  this 
purpose  they  can  be  made  to  perfectly  seal  the  apical  foramen  as  well  as 
the  entire  length  of  the  canal. 

Wood  x)oints  are  but  little  used  at  the  present  day,  although  thirty  to 
thirty-five  years  ago  they  were  for  a  time  quite  extensively  emi^loyed. 
They  had  the  advantage,  when  saturated  with  creosote,  of  remaining  per- 
manently antiseptic,  but  there  was  no  assurance  that  the  apical  foramen 
was  hermetically  sealed  unless  used  in  conjunction  with  the  plastic  mate- 
rials, or  that  when  the  point  was  driven  into  the  canal  it  did  not  project 
beyond  the  apical  foramen. 

Cotton  saturated  with  creosote  or  carbolic  acid  was  recommended  many 
years  ago  as  a  permanent  filling  for  pulp-canals  by  Dr.  J.  Foster  Flagg, 
and  for  a  long  time  it  was  extensively  emiDloyed.  It,  however,  did  not 
fulfil  the  expectations  of  some  of  its  most  ardent  advocates,  especially 
when  carbolic  acid  was  used  as  the  antiseptic,  for  pericementitis  and 
alveolar  abscess  was  not  an  infrequent  sequel  after  a  few  months  or  years. 
When  creosote  was  used  the  results  were  much  better,  as  the  antiseptic 
properties  of  this  agent  are  more  permanent.  But  neither  carbolic  acid 
nor  creosote  retain  their  antiseptic  properties  very  long  in  such  an  environ- 
ment. At  the  present  time  this  material  is  rarely  used  as  a  permanent 
pulp-canal  filling  unless  combined  with  zinc  oxychloride.  Since  the 
dentist  is  now  suj)plied  with  materials  which  are  so  much  more  reliable 
for  this  purpose,  there  seems  to  be  no  excuse  for  using  a  material  whose 
only  qualification  is  that  it  can  be  easily  introduced. 

The  writer  has  removed  many  of  the  cotton  fillings,  and  with  few  ex- 
ceptions— and  these  had  been  saturated  with  creosote — they  were  vile- 
smelling  and  disgusting,  while  some  of  them  were  saturated  with  septic 
matter,  discolored,  and  positively  rotten. 

Zinc  oxychloride  has  been  demonstrated  by  abundant  clinical  experience 
to  be  one  of  the  most  valuable  of  the  materials  employed  for  filling  pulp- 
canals.  When  mixed  to  the  consistency  of  a  creamy  paste  it  can  be 
readily  introduced  into  any  accessible  canal  by  the  aid  of  a  fine  pulp-canal 
bristle  and  using  a  gentle  pumping  motion.  Or  it  may  be  introduced 
upon  fibres  of  cotton  or  silk.  After  it  has  set  it  is  very  hard,  and  has  the 
advantage  of  remaining  antiseptic  for  a  considerable  period  thereafter,  on 
account  of  the  excess  of  the  zinc  chloride  which  is  usually  present  in  this 
cement.  Care  must  be  exercised  not  to  allow  the  cement  to  pass  the  apical 
foramen,  as  it  is  very  irritating  to  the  soft  tissues.  Its  peculiar  coagulating 
and  mummifying  effect  upon  any  remnants  of  tlie  pulp  and  the  contents  of 


PULPLESS    TEETH    AND    FILLING    PULP-CANALS.  441 

the  tnbuli  prevents  decomposition  of  these  tissues  and  preserves  the 
normal  color  of  the  dentin. 

If  the  removal  of  the  cement  become  necessary,  it  may  be  accom- 
plished with  Callahan's  method  of  enlarging  pulp-canals  with  sulphuric 
acid. 

Gutta-percha  is  also  one  of  the  most  valuable  materials  for  filling  pulp- 
canals,  many  operators  preferring  it  to  the  zinc  oxychloride. 

Gutta-percha  cones  of  proper  shape  and  length,  made  from  either  the 
base-plate  or  the  white  stopping,  when  rendered  plastic  by  heat  or  the 
action  of  chloroform,  the  volatile  extract  of  eucalyptus,  or  the  oil  of 
cajuput,  are  most  easily  and  successfully  introduced  even  into  tortuous  and 
very  fine  canals.  If  the  x^ulp- canals  are  first  filled  with  a  thin  solution  of 
chlora-percha  and  the  material  worked  as  far  towards  the  apex  as  possible 
with  a  fine  Donaldson  bristle,  or  if  moistened  with  the  volatile  extract  of 
eucalyptus,  or  the  oil  of  cajuput,  the  surface  of  the  gutta-percha  point  will 
be  rendered  plastic  and  antiseptic.  After  being  carefully  placed  in  j^osi- 
tion  and  warmed  by  a  blast  of  heated  air  directed  upon  it  from  a  hot-air 
syringe,  it  will,  under  a  little  pressure  from  the  pulp-canal  plugger,  readily 
slip  into  place,  sealing  the  apical  foramen,  and  by  adding  other  cones  the 
entire  caliber  of  the  canal  may  be  filled  to  the  orifice.  In  tortuous  canals, 
by  a  little  extra  pressure  the  fluid  gutta-percha  can  be  made  to  penetrate 
to  the  very  apex.  If  the  canal  has  been  thoroughly  dried  before  the  intro- 
duction of  the  filling,  the  gutta-percha  will  adhere  very  closely  to  the  walls 
of  the  canal.  This  material  is  unchangeable  in  such  an  environment,  and 
is  the  most  bland  and  non- irritating  to  the  soft  tissues  of  any  of  the  ma- 
terials which  are  used  for  this  purpose.  It  may  be  removed  by  first  soften- 
ing it  with  chloroform,  and  then  thrusting  a  barbed  broach  into  it  and 
twisting  the  broach  as  is  done  in  extirpating  a  devitalized  pulp. 

In  the  introduction  of  gutta-percha  points  care  should  be  taken  not 
to  use  so  much  force  in  packing  them  into  place  as  to  cause  any  portion  to 
escape  into  the  apical  space.  To  prevent  air  being  forced  into  the  space 
by  the  introduction  of  the  cone,  the  canal  should  be  first  filled  with  fluid 
chlora-percha  and  carefully  worked  to  the  apex  with  a  fine  probe.  If  the 
pressure  is  made  gently  and  the  patient  warned  to  give  notice  as  soon  as 
the  least  sensitiveness  is  felt  at  the  apex  of  the  root,  this  accident  may  be 
avoided.  This  suggestion  is  applicable  to  the  introduction  of  all  forms  of 
pulp-canal  fillings.  Pressure  of  the  filling  upon  the  tissues  of  the  apical 
space,  or  the  presence  of  air  or  septic  debris  forced  through  the  foramen  in 
front  of  the  filling,  always  induces  more  or  less  pericemental  irritation,  and 
not  infrequently  results  in  alveolar  abscess. 

Ottolengui  suggests  the  preparation  of  gutta-percha  points  or  cones  with 
a  strand  of  silk  in  the  centre,  so  that  if  it  become  necessary  to  remove  the 
filling  it  can  be  more  readily  done  if  the  cones  have  been  prepared  in  this 
manner.  His  method  of  preparing  the  cones  is  as  follows  :  '  ^  Take  floss- 
silk  and  wax  it  thoroughly,  after  which  dip  it  into  chlora-percha  and  cut 
it  into  pieces  about  an  inch  long.  These  when  dry  give  gutta-percha 
cones  which  have  a  strand  of  silk  through  them.  They  are  readily  packed 
into  the  canal,  and  the  end,  being  allowed  to  extend  beyond  the  orifice  of 


442  OPERATIVE    DENTISTRY. 

the  canal,  is  readily  grasped,  in  case  of  need,  with  a  pair  of  tweezers, 
whereupon  the  whole  root-filling  is  easily  withdrawn." 

Theo.  von  Beust,*  of  Dresden,  Germany,  suggests  the  following  method 
of  preparing  cones  for  root-fillings  :  ''Take  fine  silver  wire  of  from  0.02  to 
0.05  millimetre  in  diameter,  and  cut  from  the  different  thicknesses  of  wire 
lengths  to  correspond  to  the  different  sizes  of  root- canals.  These  are  tapered 
and  roughened  and  surrounded  with  a  film  of  gutta-percha,  making  the 
point  cylindrical  or  cone-shaped,  very  like  the  root-canal  points  bought  at 
the  dejjots.  A  hook  is  then  turned  at  the  end  of  the  point  which  is  to 
occupy  the  coronal  portion  of  the  pulp-cavity.  This  makes  an  ordinary 
root-canal  point  of  gutta-percha  with  a  core  of  wire  in  the  centre  and  a 
hook  at  the  large  end."  By  this  method  it  is  i^ossible  to  remove  the  root- 
filling  entire,  should  occasion  require,  by  simply  grasping  the  hook  with  a 
pair  of  dressing  forceps.  The  point  is  inserted  in  the  canal  after  the 
manner  already  described  for  other  gutta-percha  points. 

Chlora-percha  has  its  chief  value  in  that  it  is  capable,  while  in  the  fluid 
state,  of  being  introduced  into  portions  of  certain  canals  in  which  solid 
materials  could  not  be  made  to  enter  on  account  of  their  extreme  smallness 
or  their  tortuous  course.  It  is  valuable,  also,  as  a  lubricant  for  the  gutta- 
percha and  metal  points,  and  for  closing  the  interstices  between  these 
materials  and  the  walls  of  the  canal. 

In  introducing  chlora-percha  into  tortuous  and  very  small  canals,  it 
should  be  made  quite  thin  and  worked  towards  the  apex  as  far  as  possible 
with  fine  Donaldson  bristles  ;  then,  by  the  aid  of  the  How  probes  or  other 
suitable  instruments,  fine  threads  of  base-plate  gutta-percha  may  be  warmed 
and  packed  into  the  canals  until  they  are  full,  when,  if  the  patient  has 
given  no  response  to  the  forcing  of  the  gutta-percha  into  the  canals,  a  large 
piece  of  gutta-percha  base-i^late  may  be  warmed  and  packed  into  the  bot- 
tom of  the  cavity,  and  this  covered  with  a  pledget  of  cotton  large  enough 
to  fill  the  cavity  ;  then,  with  as  large  a  plugger  as  will  enter  the  cavity, 
pack  the  cotton,  gently  at  first,  and  gradually  increasing  the  force  until  the 
patient  feels  a  slight  pressure  at  the  apex,  when  all  further  forcing  of  the 
material  should  cease,  as  this  indicates  that  the  chlora-percha  has  reached 
the  apex  of  the  canal. 

Dr.  W.  C.  Barrett, t  of  Buffalo,  some  years  ago  most  convincingly 
demonstrated  that  not  only  would  the  chlora-percha  travel  by  this  method 
to  the  very  aiDex  of  the  canal,  but  that  it  might  also  follow  certain  minute 
canals  which  sometimes  connect  the  pulp  with  the  pericementum  at  some 
distance  from  the  apex  of  the  root. 

Salol  and  paraffin  have  been  so  recently  recommended  as  materials  for 
filling  pulp-canals  that  it  is  too  early  to  pass  judgment  ui^on  their  utility  or 
permanent  value.  They  are  both  introduced  in  the  same  manner.  A  fine 
probe  is  first  passed  into  the  canal  to  the  apex  ;  a  portion  of  the  agent  to 
be  used  is  then  taken  up  between  the  points  of  a  pair  of  dressing  pliers 
and  heated  over  an  alcohol  flame  until  it  is  melted.  While  still  hot  the 
pliers  are  inserted  into  the  cavity  of  the  tooth,  beside  the  probe,  and  then 

*  Items  of  Interest,  October,  1900,  p.  713.  t  Independent  Practitioner. 


PULPLESS    TEETH    AND    TILLING    PULP-CANALS.  443 

opened.  The  fluid  material  immediately  follows  the  probe  to  the  apex  of 
the  canal,  and  on  slowly  withdrawing  the  jjrobe  while  the  material  is  still 
fluid  it  occupies  the  space  of  the  probe  and  completely  fills  the  canal. 
Some  operators  are  in  the  habit  of  inserting  a  gutta-percha  or  a  metal  cone 
into  the  canal  while  the  material  is  still  fluid,  thus  insuring  the  material 
reaching  the  apex  and  perfectly  filling  the  whole  canal.  This  method  has 
another  advantage  which  gives  it  imi)ortance, — viz.,  if  it  become  necessary 
to  remove  the  filling,  a  blast  of  hot  air  from  a  chip-blower,  or  the  contact 
of  a  hot  instrument  with  the  filling,  will  melt  the  material  and  permit  the 
cone  of  gutta-percha  or  metal  to  be  easily  withdrawn. 

Parafiin  does  not  change  its  conditions  in  such  an  environment ;  but 
this  does  not  seem  to  be  the  case  with  salol,  as  several  reliable  observers 
have  claimed  that  it  has  disappeared  from  the  canals  in  which  it  had  been 
placed,  probably  by  volatilization  and  diffusion  through  the  dentin. 

If  pericemental  soreness  should  follow  the  permanent  filling  of  the  pulp- 
canal,  and  this  not  infrequently  happens,  it  may  be  relieved  by  painting 
the  gum  over  the  affected  tooth  with  a  counterirritant  like  tincture  of  aco- 
nite and  tincture  of  iodine,  equal  parts  of  each  ;  or  chloroform  may  be 
added  in  the  same  proportions. 

Mummification  of  the  Pulp. — It  has  been  frequently  noticed,  as  far 
back  as  the  days  when  arsenous  acid  was  employed  to  relieve  hyper- 
sensitiveness  of  the  dentin,  that  after  a  time  the  tooth  became  slightly 
discolored  and  all  sensitiveness  disappeared ;  later,  when  occasion  of- 
fered to  open  the  pulp-chamber,  the  pulp  was  found  not  only  dead,  but 
completely  desiccated  or  mummified,  although  in  many  of  these  cases  no 
pericementitis  was  ever  manifest.  It  has  also  been  noticed,  when  por- 
tions of  a  pulp,  devitalized  by  arsenous  acid,  had  been  left  in  the  apex  of 
the  root,  that  very  often  such  remnants,  after  having  been  treated  with 
creosote  or  zinc  chloride  solutions,  gave  no  further  trouble  whatever.  The 
same  conditions  often  occurred  under  fillings  and  cappings  made  of  zinc 
oxy chloride,  and  when  the  pulp- canals  were  opened,  perhaps  years  after- 
wards, the  pulps  were  found  in  a  complete  state  of  mummification. 

This  was  noticed  also  under  amalgam  fillings  made  of  cadmium  or  con- 
taining large  quantities  of  this  metal.  These  facts  have  led  many  operators 
to  experiment  with  various  antisex^tic  agents  in  the  hope  of  discovering 
some  method  whereby  it  would  be  possible  to  render  such  remnants  of 
pulp-tissue,  as  must  often  be  left  in  tortuous  and  crooked  pulp-canals,  per- 
manently aseptic,  and  thereby  insure  the  possibility  of  its  never  causing 
pericementitis  or  alveolar  abscess. 

Witzel  (1874),  according  to  Miller,*  was  the  first  experimenter  to  insti- 
tute systematic  observations  upon  the  subject.  Witzel' s  method  was  to 
devitalize  the  bulbous  portion  of  the  pulp  by  means  of  arsenous  acid,  ex- 
tirj)ate  that  part,  and  leave  the  portions  in  the  canals  undisturbed,  treating 
these  portions  as  freshly  exposed  pulps.  This  is  the  method  followed  later 
by  Herbst,  the  only  difference  being  that  Herbst  used  native  arsenic — 
cobalt — instead  of  the  regular  arsenous  acid. 

*  Proceedings  Columbian  Dental  Congress,  1893. 


444  OPERATIVE    DENTISTRY. 

A  few  cases  treated  after  this  manner  do  well,  but  the  great  majority  of 
them  sooner  or  later  develop  pericementitis  and  alveolar  abscess. 

Miller  found  that  only  a  very  small  number  of  the  antiseptic  agents 
have  any  permanent  sterilizing  action  upon  the  pulp.  These  are  the 
cyanide,  bichloride,  and  salicylate  of  mercury,  sulphate  of  copper,  and  the 
oil  of  cinnamon.  The  preparation  which  gave  the  best  results  was  com- 
posed of  mercuric  chloride,  0.0075  gramme,  and  thymol,  0.0075  gramme, 
made  into  tablets. 

The  method  of  employing  this  preparation  is  to  devitalize  the  pulp 
and  remove  all  that  is  readily  accessible,  then  place  one  of  the  tablets  in 
the  pulp-cavity,  crush  it  with  an  amalgam  plugger,  working  it  down  into 
the  canals  as  far  as  possible,  and  cover  it  with  gold-foil.  The  great  objec- 
tion to  this  preparation  is  that  the  mercuric  salt  discolors  the  tooth. 

This  same  experimenter  expresses  great  faith  in  the  power  of  the  oil 
of  cinnamon  to  permanently  sterilize  any  fragments  of  pulp -tissue  that 
may  from  necessity  be  left  in  the  pulp-canals.  The  only  objection  to  the 
use  of  this  agent,  and  also  of  oil  of  cassia,  is  their  liability  to  produce  a 
greenish  discoloration  of  the  tooth. 

Continuing  the  same  line  of  experimentation,  Soderberg  has  found  the 
following  formula  to  be  very  efficacious  as  a  means  for  permanent  pulp 
sterilization : 

B     Alum  exsic, 
Thymol, 

Glycerol,  aa  equal  parts  ; 
Zinc  oxide,  q.  s.  to  make  a  stiff  paste. 

Frith  claims  good  results  from  the  following  formulae  : 

B     Tannic  acid. 

Thymol,  aa  equal  parts  ; 

Glycerol,  q.  s.  to  make  a  stiff  paste. 

B     Mercuric  chloride, 
Thymol, 

Acidi  carbolici,  aa  2  grammes  ; 
Acidi  tannici, 

Morph.  mur.,  aa  1.5  grammes  ; 
01.  menth., 
01.  cassige,  aa  q.  s.  to  make  a  stiff  paste. 

"With  the  latter  ^ '  a  tannate  of  mercury  is  formed  ;  it  is  insoluble,  and 
but  little  pain  is  caused  by  its  absorption." 

The  method  of  applying  these  sterilizing  agents  is  to  remove  all  of 
the  pulp-tissue  that  is  possible,  then  to  place  a  portion  of  the  paste 
in  the  pulp-chamber  and  with  a  root-canal  plugger  carry  it  into  the 
canals,  and  then  add  enough  more  to  fill  the  pulp-chamber,  cover  it 
with  zinc  oxyphosphate,  and  fill  with  gold  or  amalgam  as  the  conditions 
require. 

Sdderberg  has  more  recently  suggested  that  a  small  quantity  of  cocaine 


PULPLESS   TEETH    AND   FILLING   PULP- CANALS.  445 

be  added  to  the  paste  to  prevent  tlie  pain  incident  to  the  action  of  the 
dried  alum  upon  the  pulp-tissue. 

Objections  have  been  raised  to  the  employment  of  such  methods  of 
treatment,  for  the  reason  that  it  was  feared  it  would  tend  towards  slovenly 
methods  of  operation,  as  it  would  be  much  easier  to  apply  the  paste  than 
to  carefully  follow  the  pulp-canals  until  all  remnants  of  pulp-tissue  that 
skill  and  patience  could  reach  were  removed.  The  advantages  of  the 
method  lie  in  the  possibility  of  so  sterilizing  the  remnants  which  cannot 
with  the  utmost  skill  be  removed  that  there  will  be  little  or  no  probability 
of  their  ever  causing  future  trouble. 


CHAPTEE    XXYII. 

BLEACHING   DISCOLORED   TEETH. 

Discoloration  of  a  tooth  is  tlie  result  of  tlie  deatli  of  its  pulp,  tlie  dis- 
organization of  tlie  red  blood- corpuscles,  and  tlie  dissemination  of  the 
hsemogiobin  through  the  dentinal  tubuli.  It  should  be  understood,  how- 
ever, that  in  this  connection  no  reference  is  made  to  those  metallic  stains 
resulting  from  the  oxidation  of  amalgam  fillings  containing  large  amounts 
of  silver  or  cadmium,  or  from  other  conditions  which  may  be  operative 
in  the  mouth,  like  the  chromogenic  action  of  certain  bacteria,  tobacco, 
medicines  containing  iron,  etc.  Chemistry  has  not  as  yet  discovered  any 
reliable  and  effective  method  of  removing  the  metallic  stains  caused  by 
the  oxidation  of  metal  fillings,  etc. 

The  death  of  the  pulp  does  not  of  necessity  result  in  discoloration  of 
the  tooth,  but  loss  of  its  translucency  or  vital  appearance  is  always  a  re- 
sultant of  pulp  devitalization.  This  appearance  once  lost  can  never  again 
be  restored  by  any  means  known  to  chemistry  or  dental  art.  Discolora- 
tion may  be  removed  and  the  tooth  whitened,  but  a  natural  ajipearance  in 
color  or  translucency  can  never  be  obtained.  The  removal  of  discolora- 
tion may  be  accomplished  by  two  methods :  first,  by  chemic  agents,  and 
secondly,  by  the  color  effect  obtained  by  the  introduction  of  a  white  filling- 
material  into  the  enlarged  cavity  and  pulp- canal.  By  such  means  it  is 
possible  to  greatly  improve  the  color,  and  this  improvement  is  most  marked 
in  those  teeth  which  are  most  discolored. 

The  first  noticeable  change  in  the  color  of  a  tooth  which  has  had  its 
pulp  devitalized  by  any  of  the  various  causes  which  may  produce  this 
condition  is  that  of  a  pinkish  tint. 

The  discoloration  in  devitalized  or  pulpless  teeth  ranges  from  a  pinkish 
tint  to  black.  These  gradations  in  color  pass  rapidly  ''from  the  original 
pinkish  hue,  which  becomes  yellow ;  this,  growing  darker,  passes  into 
brown,  and  after  the  lapse  of  considerable  time  the  tooth  may  become  a 
permanent  slaty  gray  or  black."     (Kirk.) 

It  is  a  notable  fact,  however,  that  the  character  of  the  agency  which 
has  caused  the  devitalization  of  the  pulj)  determines  to  a  considerable  de- 
gree the  rapidity  with  which  discoloration  of  the  tooth  ensues.  Trauma- 
tisms which  produce  severe  injury  to  the  pulp,  rupturing  its  blood-vessels 
and  causing  extravasation  of  blood  into  its  tissues,  result  in  almost  imme- 
diate discoloration  of  the  tooth.  Intense  irritation,  such  as  is  produced  by 
the  application  of  arsenic  trioxide,  zinc  chloride,  or  other  violent  irritants 
which  cause  infarction,  embolism,  or  thrombosis,  sometimes  result  in  dis- 
coloration in  less  than  twenty-four  hours  after  their  application.  A  severe 
pulpitis,  lasting  for  t\t'0  or  three  days  before  the  vitality  of  the  pulp  is 
destroyed,  does  not  cause  discoloration  nearly  so  readily  ;  while  if  the  in- 
flammation has  been  of  a  mild  type  and  the  devitalization  of  the  pulp  has 
446 


BLEACHING   DISCOLOEED   TEETH.  447 

progressed  slowly,  the  initial  discoloration  may  be  so  slight  as  to  escape 
notice  except  by  reflected  light. 

If,  however,  the  devitalized  pulp  is  permitted  to  remain  in  the  tooth 
for  any  length  of  time  the  color  gradually  grows  darker,  and  although 
it  may  never  become  so  unsightly  as  those  which  have  been  devitalized 
by  mgre  violent  irritants,  they  will  in  time  assume  a  color  which  will  call 
for  treatment  to  render  them  less  conspicuous.  Teeth,  however,  in  which 
the  pulp  has  been  removed  immediately  after  devitalization,  or  while  it  is 
in  a  state  of  irritability,  but  before  stasis,  embolism,  or  thrombosis  has 
occurred,  do  not,  as  a  rule,  become  discolored.  The  only  change  noticed 
in  them  is  the  loss  of  translucency. 

Pathology. — Black  has  found  the  coloring  matter  of  the  red  blood- 
corpuscles  in  a  crystalline  form  in  the  blood- clots  found  in  devitalized 
pulps,  and  that  while  the  clots  are  in  a  state  of  solution  from  disintegra- 
tion the  coloring  matter  may  enter  the  tubules  in  large  amount  and  cause 
the  discoloration  of  the  entire  dentin,  giving  it  a  red  color. 

The  decomposition  of  the  proteid  elements  of  the  pulp  exerts  a  pro- 
found modifying  influence*  upon  the  extent  and  the  intensity  of  the  dis- 
coloration by  the  formation  of  hydrogen  sulphide  and  its  action  upon  the 
hsemogiobin. 

Healthy  blood  contains  on  an  average  twelve  per  cent,  of  hsemoglobin. 
(Vaughn.)*  The  crj^stals  of  hiemoglobiu  have  the  bright  red  color  of  arte- 
rial blood  ;  this  explains  the  initial  pinkish  hue  or  the  red  color  which 
obtains  in  certain  teeth  immediately  after  devitalization  of  the  pulp. 
Hsemoglobin  has  the  power  of  forming  rapid  association  and  dissociation 
with  oxygen  without  affecting  the  molecular  arrangement  of  the  hsemo- 
globin itself.  In  fact,  it  is  the  oxygen  carrier  of  the  red  blood-corpuscle. 
Haemoglobin  is  a  proteid  body  combined  with  hsematin,  a  body  of  known 
composition  containing  iron  (Cj^HgjjST^FeOs). 

The  term  oxyhwmoglobin  is  used  to  designate  the  hsemoglobin  while  it 
carries  the  oxygen,  and  in  contradistinction  to  the  hsemoglobin  from  which 
the  oxygen  has  been  removed.  Arterial  blood  contains  a  considerable 
quantity  of  oxyhsemoglobin,  but  very  little  reduced  hsemoglobin  ;  while 
venous  blood  is  x)Oor  in  the  former  and  rich  in  the  latter.     (Vaughn.  )f 

The  association  of  oxygen  with  hsemoglobin,  although  a  chemic  com- 
bination, is  of  such  a  nature  that  the  oxygen  is  readily  given  up  and 
replaced  without  detriment  to  the  hsemoglobin  molecule.  The  red  blood- 
corpuscle  is  therefore  able  to  receive  its  oxygen  as  it  passes  through  the 
pulmonarj^  circulation,  and  give  it  up  again  in  its  passage  through  the 
capillary  system,  without  material  change  in  the  corpuscle  itself. 

'So  accurate  formulse  have  been  found  for  the  proteids.  Bunge  gives 
the  following  analysis  as  the  range  of  variation  in  their  composition  : 

Carbon 50.0  to  55.0  per  cent. 

Hydrogen 6.6  to    7.3  per  cent. 

Nitrogen 15.0  to  19.0  per  cent. 

Sulphur 0.3  to    2.4  per  cent. 

Oxygen 19.0  to  24.0  per  cent. 

*  Chemical  Physiology  and  Pathology.  t  Ibid. 


448  OPEEATIVE   DEJSTISTRY. 

According  to  Wurtz  their  composition  is  as  follows : 

Carbon 52.7  to  54.5  per  cent. 

Hydrogen 6.9  to    7.3  per  cent. 

Nitrogen 15.4  to  17.0  per  cent. 

Oxygen 20.9  to  23.5  per  cent. 

Sulphur 0.8  to    2.2  per  cent. 

It  will  be  seen,  therefore,  that  according  to  the  analysis  of  Biinge  the 
albumins  contain  approximately  from  6.6  to  7.3  per  cent,  of  hydrogen  and 
from  0.3  to  2.4  per  cent,  of  sulphur,  while  those  of  Wurtz  place  the  per- 
centage of  hydrogen  at  6.9  to  7.3  and  sulphur  at  0.8  to  2.2  per  cent. 

In  the  putrefaction  of  the  animal  albumins  these  substances  are  decom- 
posed into  fat,  tyrosin,  leucin,  ammonia,  hydrogen  sulphide,  carbon  dioxide, 
hydrogen,  and  nitrogen.  The  hydrogen  sulphide  is  formed  by  the  union  of 
two  atoms  of  hydrogen  with  one  of  sulphur.  This  gas  acting  upon  the 
haemoglobin  and  certain  of  its  compounds,  formed  by  decomposition, — viz., 
methsemoglobin,  hsemin,  haematin,  and  hsematoidin, — present  various  chro- 
mogenic  features  which  explain  the  color  changes  that  take  place  in  the 
tooth  during  the  decomposition  of  the  albuminoid  substances  of  the  pulp, 
the  organic  material  of  the  dentin,  and  the  haemoglobin  of  the  blood  con- 
tained in  this  organ  at  the  time  of  its  devitalization.  These  compounds 
form  various  colors.  The  crystals  of  hcemogloUn  are  bright  red  ;  those  of 
methcemogloMn  are  reddish  brown  ;  those  of  hcemin  are  dark  brown  or  black  ; 
those  of  hcematin  are  bluish  black  ;  and  those  of  hcematoidin  are  reddish  or 
orange- colored. 

'•Extravasations  of  blood  quickly  undergo  changes  which  are  visible 
even  to  the  naked  eye.  In  the  skin  they  are  at  first  brownish,  then  blue- 
green  and  yellow.  When  small  hemorrhages  have  occurred  in  the  sub- 
stance of  a  tissue,  as  the  periosteum,  pleura,  or  lung,  reddish-brown  or 
blackish  spots  will  be  visible  long  afterwards.  In  bodies  which  are  rapidly 
putrefying  these  areas  may  be  slate- colored. 

' '  Larger  hemorrhages  into  the  tissues — for  example,  in  the  brain  or  the 
lung — come  to  have  a  rusty  color  after  a  time,  and  still  later  the  affected 
spots  show  ochre-yellow,  yellowish-brown,  or  brown  pigmentation.  Corre- 
sponding with  all  these  changes  in  color  are  physical  and  chemical  changes 
in  the  haemoglobin  and  in  the  iron  contained  in  it."  * 

During  the  process  of  disintegration  of  the  red  corpuscles  of  the  blood 
the  haemoglobin  breaks  up  into  ''two  groups  of  substances,  one  containing 
iron  and  the  other  not ;  the  former  is  called  hcemosiderin,  the  latter  hw7na- 
toidin.''  t 

Hcematoidin  is  chemically  identical  with  MliruMn,  the  chief  coloring 
matter  of  the  bile  ;  and,  as  already  noticed,  it  is  reddish  or  orange- colored 
in  its  crystalline  form.  "  It  appears  to  be  more  abundant  when  the  blood- 
pigment  is  not  much  exposed  to  the  action  of  living  cells,  as  in  the  centre 
of  large  extravasations,  and  in  hemorrhages  into  preformed  cavities  of  the 
body,  as,  for  example,  into  the  pelvis  of  the  kidney  or  into  the  subdural 
space."  X    For  this  reason  it  would  seem  that  the  same  conditions  would 

*  Ziegler,  General  Pathology,  1899.  t  Ibid.  J  Ibid. 


BLEACHING   DISCOLORED   TEETH.  449 

obtain  in  a  closed  cavity  like  the  pulp-chamber,  which  had  not  been  pene- 
trated by  caries  or  traumatism,  and  which  would,  upon  the  devitalization 
of  the  pulp,  be  devoid  of  living  cells  in  contact  with  it,  and  would  thus 
explain  the  reddish  or  reddish-yellow  discoloration  of  the  teeth. 

'^  Swmosiderin,  the  derivative  of  haemoglobin  containing  iron,  is  met 
with  in  the  tissues  for  the  most  part  in  the  form  of  yellow,  orange,  or 
brown  masses  and  granules,  which  deepen  in  color  with  time.  ...  If 
hsemosiderin  comes  in  contact  with  ammonium  sulphide  (or  hydrogen  sul- 
phide, both  of  which  are  derivatives  of  the  putrefactive  decomposition  of 
the  animal  albumins),  it  becomes  black  by  the  formation  of  iron  sul- 
phide." * 

The  conditions  for  the  formation  of  iron  sulphide  are  present  in  a  tooth 
containing  a  dead  and  putrefying  pulp,  and  it  may  be  safely  inferred  that 
this  process  takes  place  within  the  tooth  as  the  result  of  the  chemic 
changes  which  are  brought  about  through  the  agency  of  the  saprophytic 
micro-organisms  acting  upon  the  proteid  elements  of  the  pulp-tissue,  the 
blood,  the  contents  of  the  tubuli,  and  the  hsematin  contained  in  the  red 
corpuscles,  the  sulphur  combining  with  the  iron  in  the  hsematin  to  form 
iron  sulphide.  Kirk  f  is  of  the  opinion  that  ^'  while  iron  sulphide  as  such 
cannot  be  held  wholly  accountable  for  the  final  bluish-black  color  of  a 
tooth  which  has  reached  the  stage  of  permanent  discoloration,  the  pig- 
mentation is  almost  certainly  due  either  to  it  or  to  some  allied  compound 
in  which  iron  and  sulphur,  with  some  organic  constituents,  largely  enter, 
and  which  by  a  further  slight  decomposition  would  yield  true  iron  sul- 
phide." 

PREPARATION  OF  THE  TOOTH  FOR  BLEACHING. 

Various  chemic  agents  have  been  suggested  for  the  purpose  of  bleach- 
ing discolored  teeth  and  restoring  them  to  their  normal  color.  The  majority 
of  these  agents  are  more  or  less  irritating  and  escharotic,  and  more  or  less 
injurious  to  the  surrounding  soft  tissues  ;  it  is  therefore  important  that  the 
tissues  of  the  apical  space  should  be  protected  by  the  introduction  of  a 
filling  that  will  hermetically  seal  the  apical  foramen,  and  at  the  same  time 
of  such  material  that  it  will  not  be  acted  upon  by  the  chemic  agent  em- 
ployed. The  only  material  used  for  filling  teeth  that  possesses  these  quali- 
ties is  gutta-percha.  To  protect  the  gums,  lips,  and  other  soft  tissues  of 
the  mouth,  and  the  adjoining  teeth,  from  the  destructive  action  of  these 
chemic  agents  the  rubber-dam  is  of  the  greatest  value ;  in  fact,  it  is  indis- 
pensable. 

The  first  step  in  the  preparation  of  a  tooth  for  the  bleaching  process —  a 
superior  central  incisor,  for  instance — is  to  freely  open  the  pulp-canal  and 
remove  any  remaining  portions  of  the  pulp  and  other  debris  by  means  of  a 
Donaldson  pulp-canal  cleanser.  This  is  to  be  followed  with  repeated  irri- 
gations with  sterilized  water  rendered  alkaline  by  the  addition  of  a  small 
quantity  of  sodium  bicarbonate.  The  cavity  of  decay,  if  one  exists, 
should  now  be  cleaned  of  all  deeply  stained  softened  dentin,  and  thepulp- 

*  Ziegler,  General  Pathology,  1899. 
t  American  Text-Book  of  Operative  Dentistry. 
29 


450  OPERATIVE    DENTISTRY. 

chamber  and  canal  enlarged  with  suitable  burs  and  reamers.  If  perice- 
mental irritation  exists,  this  condition  must  first  be  abated. 

The  rubber  dam  should  now  be  adjusted,  but  to  the  tooth  only  that  is 
to  be  operated  upon,  as  by  this  means  there  is  less  danger  from  leakage 
than  when  two  or  more  adjoining  teeth  are  included  in  the  dam,  while  the 
adjoining  teeth  are  protected  against  injury  from  any  disintegrating  or 
solvent  action  upon  the  enamel  which  might  be  possessed  by  the  chemic 
agents  used  for  the  purpose  of  bleaching.  To  secure  the  dam  from  slip- 
]Ding  off  the  tooth,  and  to  guard  against  every  possibility  of  leakage,  a 
waxed  ligature  should  be  wrapped  three  or  four  times  about  the  tooth  at 
the  cervix  and  tied  with  the  surgeon's  knot.  Added  security  may  be  ob- 
tained by  coating  the  ligature, — after  it  is  in  place, — the  cervix  of  the  tooth, 
and  the  rubber  dam  at  this  point  with  liquid  chlora-percha. 

The  cavity  and  the  pulp-canal  should  now  be  dried  with  bibulous 
paper  and  amadou  as  thoroughly  as  may  be  with  these  absorbent  agents, 
and  further  dehydrated  by  means  of  a  Wooley  or  an  Evans  root- dryer  or 
the  hot-air  sj^ringe.  The  root-canal  should  now  be  filled  with  gutta-percha, 
which  should  not  include  more  than  the  apical  third  or  half  of  the  canal, 
for  the  reason  that  the  discoloration  of  the  tooth  is  most  intense  at  the  cer- 
vix and  immediately  beyond  towards  the  apex,  and  if,  as  frequently  hap- 
pens, there  is  recession  of  the  gum,  it  is  important  that  the  bleaching 
process  be  carried  beyond  this  point. 

All  fillings  of  every  kind  which  may  be  present  in  the  tooth- crown 
should  be  removed  before  the  bleaching  process  is  commenced.  This  is 
especially  necessary  if  the  bleaching  agent  to  be  employed  is  one  that  con- 
tains chlorine,  as  this  element  readily  combines  with  iron,  gold,  platinum, 
and  other  metals,  forming  soluble  chlorides  which,  if  i)ermitted  to  penetrate 
the  tubular  structure  of  the  dentin,  will  cause  iDcrmanent  discolorations 
that  are  well-nigh  impossible  to  remove.  For  this  reason,  also,  the  instru- 
ments which  are  used  for  mixing  and  introducing  bleaching  agents  of  this 
character  should  be  made  of  wood  or  ivory.  Another  advantage  in  re- 
moving the  fillings  from  such  a  tooth  is  the  increased  surface  which  is 
thus  exposed  to  the  action  of  the  bleaching  agent. 

The  cavity  should  next  be  thoroughly  prei^ared  by  removing  all  remains 
of  softened  dentin,  thin  walls  of  enamel,  and  any  septic  or  other  foreign 
substance.  Kirk  recommends  washing  the  cavity  after  it  is  prepared  with 
dilute  ammonia  water,  or  a  hot  solution  of  borax  in  distilled  water  in 
the  proportion  of  one  drachm  to  one  ounce,  to  saponify  and  remove  by 
solution  all  fatty  matters  which  might  otherwise  obstruct  the  entrance  of 
the  bleaching  agent  to  the  tubular  structures  of  the  dentin.  The  surplus 
moisture  should  next  be  removed,  and  the  tooth  is  then  in  condition  for 
the  bleaching  process. 

Method  of  bleaching  Teeth. — The  chemic  agents  which  have  been 
most  successfully  used  for  the  jDurpose  of  bleaching  discoloi-ed  teeth  are  of 
two  classes, — oxidizing  agents  and  reducing  agents.  The  former  destroy  the 
color  molecule  by  virtue  of  their  power  to  evolve  oxygen  in  a  nascent  state. 
The  latter  act  in  an  opposite  manner  by  virtue  of  their  great  affinity  for 
oxygen,  seizing  upon  the  oxygen  element  of  the  color  molecule  to  form  by- 


BLEACHING   DISCOLORED   TEETH.  451 

products,  the  character  of  which  depends  upon  the  chemic  composition  of 
the  reducing  agent  employed. 

The  oxidizing  agents  are  divided  into  two  forms, — viz.,  indirect  oxidizers 
and  direct  oxidizers. 

The  indirect  oxidizing  agents  which  are  employed  for  bleaching  teeth 
are  chlorine  in  the  form  of  chlorinated  lime,  chlorinated  soda  (Labarraque's 
solution),  aluminum  chloride,  free  chlorine  gas,  and  iodine  and  bromine;  the 
latter  being  used  to  remove  various  special  metallic  stains. 

The  direct  oxidizing  agents  are  hydrogen  dioxide,  sodium  dioxide,  and 
potassium  permanganate. 

The  reducing  type  of  bleaching  agents  is  represented  by  sidphurous 
acid. 

Chlorine  Methods.— Chlorine  (CI)  has  a  strong  affinity  for  all  metallic 
substances,  and  under  favorable  circumstances  enters  with  great  energy 
into  direct  combination  with  them,  forming  compounds  which  are  generally 
soluble  in  water. 

One  of  the  chief  characteristics  of  chlorine  is  its  strong  affinity  for 
hydrogen  (H)  wherever  found.  This  peculiarity  is  utilized  in  the  opera- 
tion of  bleaching  teeth  by  liberating  the  chlorine  which  is  held  in  combina- 
tion with  the  calcium,  sodium,  and  aluminum  of  the  above-mentioned 
compounds.  The  bleaching  power  of  the  chlorine  is  exerted  upon  the 
color  molecule  by  seizing  upon  its  hydrogen  element  and  liberating  the 
oxygen  (O)  contained  in  it.  The  oxygen  thus  liberated  is  in  the  nascent 
state,  and  in  this  form  it  acts  most  powerfully  as  an  oxidizing  agent.  By 
the  union  of  the  chlorine  with  the  hydrogen  element  of  the  color  molecule, 
or  other  molecules  containing  hydrogen,  chlorhydric  acid  (HCl)  is  formed, 
and  the  identity  of  the  substance  acted  upon  is  destroyed. 

The  Truman  Method. — Dr.  James  Truman  (1864)  introduced  the 
first  successful  method  of  bleaching  discolored  teeth.  His  method  consists 
substantially  of  liberating  chlorine  from  chlorinated  lime  by  the  addition  of 
a  weak  solution  of  acetic,  tartaric,  or  oxalic  acid.  Dr.  Truman  has  sug- 
gested several  ways  by  which  the  chlorinated  lime  and  the  acid  may  be 
brought  together.  "One  process  is  to  saturate  the  entire  canal  and  the 
pulp-chamber  with  the  acid  before  inserting  the  chlorinated  lime  5  another 
is  to  dip  the  instrument  in  the  weak  solution  of  acid,  and  then  in  the  lime, 
and  pack  it  rajDidly  into  the  cavity  ;  and  still  another  is  to  make  a  paste 
^by  the  use  of  distilled  water,  and  pack  this  into  the  tooth,  and  then  apply 
a  stronger  acid  solution  by  means  of  cotton  wrapped  around  the  point 
used."  * 

The  cavity  is  then  quickly  sealed  with  gutta-percha,  zinc  oxychloride, 
or  zinc  oxyphosphate.  This  method  to  be  repeated  every  two  or  three 
days  until  the  required  shade  is  obtained. 

The  failures  which  occur  by  the  use  of  this  method  are  due,  in  the 
opinion  of  Dr.  Truman,  to  defective  manipulation,  princij)ally  in  the  em- 
ployment of  steel  or  any  metal  instruments, — as  by  their  use  metallic  com- 
pounds are  formed  with  the  chlorine  and  permanent  discolorations  result, — 

*  American  System  of  Dentistry. 


452  OPERATIVE   DENTISTRY. 

and  in  the  non-employment  of  distilled  water  in  the  various  manipulations, 
for  reasons  that  are  manifest. 

After  the  desired  color  is  obtained,  the  tooth  must  be  filled  with  some 
material  which  will  by  its  antiseptic  and  coagulating  qualities  prevent  the 
future  decomposition  of  the  contents  of  the  dentinal  tubuli.  Dr.  Truman 
thinks  zinc  oxychloride  possesses  these  qualities  in  a  remarkable  degree, 
and  experience  proves  it  to  be  a  most  satisfactory  substance  for  this  purpose. 
After  the  cement  has  set  it  should  be  protected  with  a  gold  filling. 

In  the  employment  of  chlorinated  soda  for  the  purpose  of  bleaching  a 
tooth,  the  dentin  is  dehydrated  as  thoroughly  as  possible  by  the  usual 
means,  and  afterwards  saturated  with  the  solution.  A  j)iece  of  absorbent 
cotton  may  then  be  saturated  with  a  weak  acid  solution,  placed  in  the 
cavity,  and  sealed  in.  The  chemical  action  is  substantially  the  same  as 
when  chlorinated  lime  is  employed, — viz.,  the  liberation  of  chlorine  which 
combines  with  the  hydrogen  element  of  the  color  molecule,  and  sets  free 
the  oxygen  element  in  a  nascent  state.  • 

Another  method  of  bleaching  teeth  with  chlorine  is  that  invented  by 
Dr.  Wright,  of  Richmond,  Virginia.  This  method  consisted  of  forcing  a 
continuous  stream  of  chlorine  gas — previously  prepared  in  the  laboratory 
— into  the  pulp-canal  and  cavity  of  the  tooth  by  an  elaborate  apparatus 
made  especially  for  the  purpose.  The  method  was  very  efficient  and  rapid 
in  its  action,  but  the  complications  of  the  apparatus  and  the  trouble  of 
preparing  the  gas  were  obstacles  which  prevented  its  general  adoption, 
and  it  was  therefore  abandoned. 

Dioxide  Methodst — Hydrogen  dioxide  (HjOj)  is  one  of  the  class  of 
direct  oxidizing  agents.  Its  value  as  a  bleaching  agent  lies  in  the  fact  that 
one  of  its  atoms  of  oxygen  is  bound  to  the  water  molecule  by  such  a  weak 
chemic  combination  that  it  is  readily  disrupted,  and  one  of  its  atoms  of 
oxygen  liberated,  as  nascent  oxygen.  Many  substances  are  capable  of 
disrupting  this  compound  and  converting  it  into  water  (H.^O)  and  free 
oxygen  (O).  Contact  with  fresh  blood,  pus,  salivary  secretions,  inspis- 
sated mucus,  albumin,  and  nearly  every  form  of  dead  organic  matter, 
causes  disruption  of  the  compound,  the  evolution  of  oxygen,  and  the 
decomposition,  wholly  or  in  part,  of  the  organic  matter  with  which  it 
comes  in  contact.  These  characteristics  make  it  not  only  a  very  valuable 
means  for  bleaching  discolored  teeth,  but  also  as  a  cleansing  agent  and 
germicide  in  all  operations  upon  the  teeth  and  in  diseased  conditions  of 
the  mouth. 

The  ordinary  three  or  four  per  cent,  aqueous  solutions  of  hydrogen 
dioxide  are  of  little  value  for  the  purpose  of  bleaching  the  teeth,  as  they 
are  very  unstable  if  kept  for  any  length  of  time. 

Since  the  introduction  of  the  ethereal  solution  prepared  by  McKesson 
and  Eobbins,  of  N'ew  York,  known  as  '^caustic  pyrozone,"  which  contains 
twenty-five  per  cent,  of  hydrogen  dioxide,  the  question  of  bleaching  by 
the  direct  method  has  been  solved,  and  this  preparation  is  now  largely  used 
when  this  method  is  employed. 

The  process  of  bleaching  by  this  method  is  to  apply  the  twenty- five 
per  cent,  ethereal  solution  to  the  pulp -canal  and  the  cavity  by  means  of 


BLEACHING  DISCOLORED   TEETH.  453 

loosely  twisted  wisps  of  cotton,  and  following  each  application  with  blasts 
of  heated  air  from  the  hot-air  syringe  until  complete  evaporation  of  the 
menstruum  is  obtained.  This  process  is  repeated  two  or  three  times  at  the 
same  sitting,  or  until  the  desired  restoration  of  color  is  secured.  Failing 
in  this,  an  application  of  pyrozone  may  be  sealed  in  the  cavity  and  per- 
mitted to  remain  for  one  or  two  days,  when  upon  removing  it  and  making 
another  application  and  evaporating  it  to  dryness  the  color  will  usually  be 
restored. 

The  pyrozone  seems,  from  experience,  to  act  more  rapidly  and  its  re- 
sults to  be  more  permanent  if  it  has  been  rendered  alkaline  before  apply- 
ing it  '^by  the  addition  of  a  few  drops  of  ammonice  fortior,  or  by  the  solu- 
tion of  one  of  the  caustic  alkalies, — e.g.,  sodium  or  potassium  hydroxide 
or  sodium  dioxide."  * 

Dr.  D.  I^.  McQuillen,  of  Philadelphia,  has  suggested  the  treatment  of 
the  pulp-canal  and  cavity  with  Schreier's  kalium-natrium  preparation  to 
secure  the  alkaline  effect  in  the  process.  The  debris  caused  by  the  action 
of  the  kalium-natrium  is  then  carefully  removed  with  instruments  and 
pellets  of  cotton,  the  usual  washing  omitted,  and  the  pyrozone  applied  as 
above. 

This  method  gives  most  excellent  results,  both  in  the  greater  rapidity 
with  which  the  bleaching  process  takes  place  and  in  the  permanency  of 
the  results.  As  soon  as  the  desired  restoration  of  color  is  obtained  the 
tooth  should  be  filled  temporarily  with  some  material  which  can  be  easily 
removed,  so  that  if  discoloration  returns  the  bleaching  process  may  be 
again  applied  with  little  loss  of  time,  l^o  tooth  which  has  been  bleached 
should  be  permanently  filled  for  at  least  two  or  three  months,  or  even 
longer,  that  the  permanency  of  the  restored  color  may  be  assured  before 
this  operation  is  undertaken. 

Dr.  A.  W.  Harlan,  of  Chicago,  introduced  the  use  of  aluminum  chloride 
in  connection  with  hydrogen  dioxide.  His  method  is  to  pack  the  aluminum 
salt  into  the  cavity  and  then  to  moisten  it  with  hydrogen  dioxide.  This 
was  originally  thought  to  be  a  chlorine  process,  whereby  the  chlorine  in 
the  aluminum  salt  was  liberated  by  the  action  of  the  hydrogen  dioxide  ; 
but  later  experimentation  has  shown  that  the  reaction  is  due  to  the  cata- 
lytic action  of  the  aluminum  salt,  and  that  the  hydrogen  dioxide  compound 
is  disrupted  by  contact  with  the  former  and  nascent  oxygen  is  set  free. 
Kirk  suggests  that  inasmuch  as  aluminum  chloride  is  an  active  coagu- 
lant, it  is  contraindicated  in  the  bleaching  of  teeth  until  the  process  has 
reached  the  stage  where  a  fixative  is  needed  to  j)revent  further  decomposi- 
tion in  the  tubular  structure  of  the  dentin. 

Sodium  dioxide  (Na^O.^)  is  another  of  the  class  known  as  direct  oxidizing 
agents.  It  is  similar  to  hydrogen  dioxide  in  that  its  combination  with  one 
of  its  atoms  of  oxygen  is  so  weak  that  it  readily  gives  it  up  when  subjected 
to  the  same  conditions  that  cause  hydrogen  dioxide  to  part  with  one  of  its 
atoms  of  oxygen.  The  essential  difference,  however,  lies  in  the  character 
of  the  by-products  which  are  formed  after  its  decomposition. 

*  Kirk,  American  Text- Book  of  Operative  Dentistry. 


454  OPERATIVE    DENTISTRY. 

Sodium  dioxide  is  a  strong  caustic  alkali,  and  after  the  loss  of  one  of 
its  atoms  of  oxygen  it  becomes  N'a.O,  still  retaining  its  caustic  and  alkaline 
properties.  When  combined  with  water  it  is  the  ordinary  caustic  soda. 
The  value  which  is  possessed  by  sodium  dioxide  as  an  oxidizing  or  bleach- 
ing agent  lies  not  only  in  the  fact  that  its  liberated  atom  of  oxygen  attacks 
the  color  molecule,  but  that  it  possesses  great  saponifying  powers,  which 
reach  the  oils  and  fats  contained  in  the  structures  of  the  tooth  and  dissolve 
any  organic  matter  still  remaining. 

"  For  use  as  a  bleaching  agent  it  is  applied  to  the  dentin  in  a  saturated 
solution.  In  making  the  solution  especial  care  is  necessary  in  order  to 
avoid  elevation  of  temi^erature,  by  reason  of  the  energy  with  which  it 
enters  into  combination  with  the  water.  If  the  solution  is  allowed  to 
become  heated  in  the  making,  decomposition  of  the  compound  with  loss 
of  oxygen  occurs  and  its  bleaching  power  is  destroyed.  The  solution  is 
best  made  by  pouring  into  a  small  beaker,  of  about  one  ounce  capacity, 
two  drachms  of  distilled  water  and  immersing  the  beaker  in  a  large  vessel 
or  dish  containing  ice-water  or  pounded  ice.  The  can  containing  the 
dioxide  powder  should  then  have  its  lid  perforated  with  a  number  of  small 
holes  similar  to  the  lid  of  a  pepper  caster,  and  the  powder  be  slowly  dusted 
into  the  distilled  water  in  the  small  beaker.  The  powder  is  added  to  the 
water  until  the  solution  assumes  a  semi-opaque  appearance,  indicating  the 
point  of  saturation.  On  removing  the  beaker  from  the  cooling  mixture, 
the  dioxide  solution  will  in  a  few  minutes  assume  a  transparent  straw- 
colored  appearance  and  be  ready  for  use. ' '  * 

The  method  of  apx)lication  is  similar  to  that  employed  when  hydrogen 
dioxide  is  used,  with  the  exception  that  pieces  of  asbestos  felt  are  used 
instead  of  cotton  with  which  to  make  the  application,  as  the  cotton  fibre 
is  acted  upon  by  the  sodium  dioxide  and  converted  into  an  amyloid  sub- 
stance which  interferes  with  the  bleaching  process  of  the  solution. 

After  the  dentin  has  been  thoroughly  saturated  with  this  solution  a  ten 
per  cent,  solution  of  sulphuric  acid  is  applied,  which  neutralizes  the  alka- 
line condition,  causing  effervescence  and  the  formation  of  sodium  sulphate 
and  hydrogen  dioxide. 

The  particular  value  of  this  method  lies  in  the  fact  that  it  not  only 
destroys  the  integrity  of  the  color  molecule,  but  the  caustic  alkali  exerts 
a  solvent  action  upon  the  organic  material  remaining  in  the  dentinal 
tubuli,  while  the  reaction  which  causes  effervescence  in  the  tubuli  com- 
pletely removes  the  debris  by  mechanically  forcing  it  out  of  the  tubuli. 

It  may  be  necessary  to  reapply  the  sodium  dioxide,  as  one  application 
does  not  always  restore  the  color.  Before  doing  this,  however,  the  tooth 
should  be  thoroughly  washed  with  hot  distilled  water.  In  the  second  appli- 
cation the  acid  should  be  omitted.  After  the  color  is  restored  the  tooth 
should  be  again  thoroughly  washed  with  hot  water  to  remove  all  debris, 
and  after  thorough  desiccation  the  tooth  is  ready  for  the  filling.  Kirk 
recommends  varnishing  the  walls  of  the  cavity  before  introducing  the  fill- 
ing.    Zinc  oxychloride  and  zinc  oxyphosphate  cements  are  the  best  for 

*  Kirk,  American  Text-Book  of  Operative  Dentistry,  p.  437. 


BLEACHING    DISCOLORED    TEETH.  455 

these  fillings  on  account  of  their  better  color,  while  the  zinc  chloride  by 
its  coagulating  effect  will  effectually  prevent  putrefactive  changes  taking 
place  in  any  portions  of  organic  matter  which  might  remain  in  the  tubuli. 

Kirk  claims  for  this  method  that  it  not  only  restores  the  color  of  the 
tooth  but  normal  translucency  as  well,  and  he  thinks  the  opaque,  white 
effect  which  results  from  other  methods  is  due  to  the  bleached  organic 
debris  remaining  in  the  tubuli,  while  in  the  sodium  dioxide  method  this 
is  removed  by  the  solvent  action  of  the  strong  caustic  alkali. 

Sulphurous  Anhydride  Method. — ASfitZpAwrows  acM  (sulphurous  anhy- 
dride, SO,)  is  the  only  one  of  the  class  of  reducing  agents  that  is  used  in 
the  operation  of  bleaching  teeth.  Its  value  as  a  bleaching  agent  resides 
in  its  strong  af&nity  for  oxygen.  When  applied  to  a  discolored  tooth,  it 
decomposes  the  color  molecule  and  combines  with  its  oxygen  element,  thus 
destroying  the  identity  of  the  molecule  and  of  the  color.  Various  methods 
have  been  suggested  for  utilizing  the  bleaching  property  of  sulphurous  acid 
by  the  direct  application  of  the  gas  to  the  root-canal  of  discolored  teeth. 

One  of  these  methods  comprehended  making  a  solution  of  the  gas  in 
water  and  applying  the  solution  to  the  pulp-canal  and  the  cavity.  Another 
was  to  ignite,  by  means  of  the  electric  cautery,  a  small  piece  of  sulphur 
which  had  been  placed  in  the  pulp-canal.  Both  of  these  methods  are  oj)en 
to  serious  objections  from  the  disagreeable  odor  and  from  their  limited 
efficiency.  To  be  efficient  the  gas  must  be  confined  within  the  cavity  for 
some  time,  and  with  neither  of  these  methods  is  such  confinement  possible. 

Kirk  *  has  devised  a  method  whereby  it  is  possible  to  generate  the  gas 
from  compounds  placed  within  the  pulj)-cavity,  and  confine  it  there  as  in 
the  chlorine  process  of  Dr.  Truman.  The  bleaching  compound  is  made 
as  follows  :  "One  hundred  grains  of  sodium  sulphite  and  seventy  grains 
of  boric  acid  are  separately  desiccated  and  afterwards  ground  together  in  a 
warm,  dry  mortar.  The  powder  is  then  to  be  transferred  to  a  tightly 
stoppered  bottle.  For  bleaching  purposes  the  powder  is  packed  into  the 
root-canal  and  cavity  of  the  t<)oth,  and  then  moistened  with  a  drop  of  water, 
and  the  cavity  immediately  closed  as  tightly  as  possible  with  a  stopping 
of  gutta-percha,  previously  prepared  and  warmed.  A  reaction  ensues 
between  the  boric  acid  and  the  sodium  sulphite  whereby  sulphurous  acid 
is  liberated.  The  i^rocess  is  effective  in  many  cases  where  the  chlorine 
methods  have  failed,  but  is  slow  in  its  action,  and  is  largely  superseded  by 
the  dioxide- of- hydrogen  and  dioxide-of-sodium  methods." 

Cataphoric  Method. — In  the  bleaching  of  the  teeth  by  the  cataphoric 
method  the  power  of  the  continuous  galvanic  current  to  disseminate,  dif- 
fuse, and  carry  remedies  into  and  through  animal  tissues  is  taken  advan- 
tage of  to  bring  about  a  more  complete  and  perfect  dissemination  of  the 
certain  bleaching  fluids  used  to  restore  the  color  of  devitalized  teeth. 

The  same  electric  apiDaratus  and  appliances  emiDloyed  in  the  treatment 
of  hypersensitive  dentin  are  used  in  this  method  of  bleaching  teeth.  The 
principles  involving  the  application  of  the  current  and  its  control  are  also 
the  same  (see  Chapter  XIIL),  the  only  difference  being  that  the  resistance 

*  American  Text-Book  of  Operative  Dentistry,  p.  439. 


456 


OPERATIVE   DENTISTRY. 


Fig.  565. 


offered  by  a  devitalized  tooth  is  mucli  greater  than  that  of  a  vital  tooth, 
which  necessitates  a  much  higher  voltage  (pressure)  to  carry  the  bleaching 
agent  into  the  dentin.  "While  a  current  pressure  of  ten  volts  is  all  that 
can  be  utilized  in  the  treatment  of  hypersensitive  dentin,  twenty-five  to 
thirty,  and  even  sixty  volts,  are  sometimes  required  to  drive  a  current  of 
one  and  one-half  milliamperes  through  devitalized  dentin. 

The  bleaching  fluid  which  is  used  in  connection  with  the  galvanic  cur- 
rent is  a  twenty-five  per  cent,  aqueous  solution  of  hydrogen  dioxide  to 
which  has  been  added  a  small  quantity  of  sodium  chloride,  sufficient  to 
give  it  the  strength  of  the  normal  salt  solution  used  in  transfusion, — one 
drachm  to  a  pint  of  warm  sterilized  water, — as  the  addition  of  this  salt 
increases  the  conductivity  of  the  fiuid.  The  ethereal  solution  of  hydrogen 
dioxide  is  too  resistant  to  the  current  to  be  utilized  in  this  connection. 

To  prepare  a  twenty-five  per  cent,  aqueous  solution  of  hydrogen  diox- 
ide, place  in  a  test-tube  one  volume  of  normal  salt  solution  and  two  volumes 
of  twenty-five  per  cent,  ethereal  solution  of  hydrogen  dioxide,  and  mix  by 
shaking  the  test-tube.  To  remove  the  ether,  place  the  solution  in  a  small 
porcelain  evaporating  dish  and  gently  heat  over  a  water-bath  until  the 
ether  is  all  evaporated,  care  being  used  not  to  allow  the  flame  of  the  lamp 
to  ignite  the  ether  vapor.  The  hydrogen  dioxide  is  thus 
dissolved  in  the  water  and  the  ether  dispelled.  Dr. 
Hollingsworth  recommends  adding  one  per  cent,  of  zinc 
sulphate  to  the  solution,  which  diminishes  the  resistance 
and  exerts  a  coagulating  effect  upon  the  organic  matter 
of  the  dentin,  which  gives  translucency  to  the  dentin  and 
enhances  the  permanency  of  the  operation. 

The  same  care  must  be  exercised  in  isolating  the 
tooth  by  the  rubber  dam,  and  securing  it  against  leakage 
of  moisture  or  leakage  of  the  electric  current,  that  is 
exercised  in  the  treatment  of  hypersensitive  dentin  as 
already  described  in  detail  in  the  chapter  previously 
referred  to. 

The  tooth  being  ready  for  the  bleaching  process,  the 
aqueous  solution  of  hydrogen  dioxide  is  applied  to  the 
tooth-cavity  on  a  pledget  of  cotton,  which  must  at  all 
times  be  kept  moist  with  it,  and  the  platinum  point  of 
a  suitable  anodal  electrode  placed  in  contact  with  it. 
The  cathodal  electrode,  covered  with  sponge  and  moist- 
ened with  the  sodium  chloride  solution,  may  be  held  in 
the  hand  or  applied  to  the  side  of  the  face  or  neck,  and 
the  current  turned  on,  the  same  precautions  being  taken 
as  when  treating  hypersensitive  dentin. 

Short  circuiting  of  the  current  is  liable  to   occur 
if  great  care  is  not  taken  to  keep  the  external   sur- 
faces of  the  tooth  dry. 

Some  operators  apply  the  cathode  to  the  external  surface  of  the  tooth, 
and  claim  that  more  rapid  effects  are  obtained  on  account  of  the  shorter 
distance  which  the  current  has  to  travel.     There  is,  however,  considerable 


Syringe  electrode. 


BLEACHING    DISCOLORED    TEETH. 


457 


danger  of  short-circuiting  the  current  if  the  external  surface  of  the  tooth 
should  become  moistened,  or  by  a  movement  of  the  patient  the  electrodes 
should  accidentally  come  in  contact  with  each  other. 

The  Hollingsworth  syringe  electrode  (Fig.  565)  may  be  used  to  keep  the 
cotton  moist  with  the  bleaching  fluid. 

To  successfully  employ  the  aqueous  solution  of  hydrogen  dioxide  with 
the  electric  current,  it  is  necessary  to  use  a  device  which  will  permit  the 
whole  crown  of  the  tooth  to  be  enveloped  in  the  bleaching  fluid. 

Such  a  device  has  been  invented  by  Dr.  Hollingsworth,  and  described 
by  him  as  follows:  ''The  bleaching  electrode  consists  of  a  curved  glass 
tube,  with  a  metal  top  at  one  end,  connecting  with  a  spiral  platinum  wire 
in  the  tube  (Fig.  566)  and  a  rubber  nipple  (a)  at  the  other  end  to  enclose 
the  tooth  to  be  bleached.  A  metal  cap  plug  (&)  prevents  the  bleaching 
fluid  from  escaping,  and  the  tip  is  provided  with  a  groove  for  the  at- 
tachment of  the  connecting  cord.  The  appliance  is  held  in  place  by  the 
hooks  attached  to  the  metal  tip  of  the  tube,  which  are  caught  over  the  top 
of  the  rubber  dam. 

"The  duplex  syringe  (Fig.  567)  is  for  the  purpose  of  filling  the  tube 
and  nipple  with  the  bleaching  fluid.    The  nozzle  connects  only  with  the  rear 

Fig.  566. 


Fig.  567. 


Bleaching  electrode. 


Duplex  syringe. 


bulb.  When  this  is  charged  with  the  bleaching  fluid  the  nozzle  is  inserted 
in  the  tube  of  the  bleaching  electrode,  first  compressing  the  forward  bulb 
and  allowing  it  to  expand  to  exhaust  the  air  in  the  tube  and  nipple,  when 
pressure  upon  the  rear  bulb  forces  the  bleaching  fluid  into  the  electrode. 

"The  nipple- expander  (Fig.  568)  is  for  adjusting  the  rubber  nij)ple  to 
the  tooth  that  is  to  be  bleached.  The  closed  end  of  the  nipple  is  first 
perforated  with  the  rubber- dam  punch,  and  when  placed  upon  the  tooth 
and  ligated  forms  a  close-fitting  and  tight  holder  for  the  bleaching  fluid." 

Before  adjusting  the  bleaching  electrode,  the  tooth  should  be  prepared 
as  for  bleaching  by  any  of  the  methods  already  described  ;  the  pulp-canal 
and  the  tooth-cavity  are  then  loosely  packed  with  cotton  previously  satu- 
rated with  the  bleaching  fluid.     The  object  of  this  is  to  form  a  conductor 


458 


OPERATIVE    DENTISTRY. 


that  will  carry  the  fluid  to  the  remote  recesses  of  the  cavity  and  canal,  and 
also  to  exclude  air-bubbles  which  would  act  as  insulators  of  the  electric 

current. 

Fig.  568. 


Nipple-expander. 

The  first  step  in  the  adjustment  of  the  electrode  is  the  placing  of  the  rubber 
nipple  in  position  by  means  of  the  nipple-expander  (Fig.  568)  and  securing 
it  firmly  by  a  ligature  passed  around  it  at  the  cervix  of  the  tooth,  varnish 
or  chlora-percha  to  be  flowed  over  it  as  an  added  precaution  against  leakage. 
The  free  end  of  the  nipple  is  now  forced  over  the  shouldered  end  of 
the  glass  tube  and  the  hooks  adjusted  to  hold  the  opposite  end  of  the  tube 
in  position.  The  tube  is  now  to  be  filled  with  the  bleaching  fluid  by  in- 
serting the  nozzle  of  the  duplex  syringe — which  has  been  previously 
charged — into  the  metal  tip  of  the  tube,  compressing  the  forward  bulb  to 
exhaust  the  air.  If  air  finds  its  way  into  the  tube  at  the  cervix  of  the 
tooth  beneath  the  margins  of  the  rubber  nipple,  varnish  may  be  again  ap- 
plied, and  suction  will  draw  it  into  and  fill  any  little  interstices  which 
might  give  access  to  air.  The  rear  bulb  is  comjDressed  and  the  tube  filled 
with  the  bleaching  fluids,  thus  submerging  and  surrounding  the  crown  of 

the  tooth  in  the  fluid.    The 
^^"     '  ■  positive    pole    is    now   con- 

nected with  the  metal  end  of 
the  tube  and  the  negative 
pole  with  the  hand  electrode, 
and  these  with  the  source  of 
the  current. 

Fig.  569  shows  the  bleach- 
ing electrode  in  position  and 
connected  with  the  positive 
pole. 

The  current  should  be 
turned  on  slowly  and  the 
milliampere- meter  closely  watched  ;  a  leak  in  the  current  is  indicated  by 
the  registration  of  a  greater  amperage  than  is  usually  employed  in  such 
operations, — viz.,  one-tenth  to  one-half  a  milliampere  upon  vital  teeth, 
which  is  increased  to  one  and  sometimes  one  and  one-half  milliamperes  in 
bleaching  devitalized  teeth. 


CHAPTEE    XXVIII. 

DISEASES   OF  THE  PERICEMENTUM. 

The  pericementum  or  peridental  membrane  is  often  the  seat  of  various 
diseased,  conditions,  both  nutritive  and  functional.  Among  these  are 
several  distinct  forms  of  inflammation,  all  arising  from  different  causes, 
some  local  in  origin,  others  constitutional,  and  each  requiring,  according 
to  their  origin,  a  different  line  of  treatment  for  their  cure. 

B5decker  classifies  the  diseases  of  the  pericementum  under  two  heads, 
' — viz.,  purulent  and  non-purulent.  Burchard  thinks  this  is  misleading,  as 
cases  may  be  due  to  septic  causes  without  pus-formation,  while  pus-forma- 
tion represents  but  one  form  of  sepsis.  Burchard  *  classifies  them  as  septic 
and  non-sejriic. 

Black  t  classifies  the  disorders  of  the  pericementum  under  three  heads  : 
first,  diseases  which  begin  at  the  apex  of  the  root ;  second,  those  which 
begin  at  the  border  of  the  gingivae  ;  third,  those  beginning  at  some  inter- 
mediate portion  of  the  membrane.  These  are  again  divided  into  septic 
and  non-septic,  general  and  localized,  acute  and  chronic. 

pericementitis. 

Definition. — Pericementitis  (from  the  Greek  T:£pt,  around;  Latin, 
ccementum.  cement ;  Greek,  cr:?,  itis,  the  ending,  signifying  inflammation), 
inflammation  of  the  pericementum  or  peridental  membrane  and  the  tissues 
immediately  surrounding  the  tooth. 

Inflammation  of  the  investing  membrane  of  the  roots  of  the  teeth  is 
therefore  termed  pericementitis,  periodontitis,  or  dental  periostitis. 

Next  to  hypersemia  and  inflammation  of  the  pulp,  pericementitis  is  the 
most  prolific  cause  of  toothache.  It  therefore  calls  for  a  careful  study  of 
its  pathology  and  its  symptoms,  that  it  may  with  certainty  be  differen- 
tiated from  other  affections  which  cause  odontalgia. 

Causes. — Pericementitis  may  be  divided  into  two  distinct  forms,  one 
dependent  upon  local  causes  for  its  existence,  the  other  upon  general  or 
constitutional  conditions,  and  these  forms  may  be  either  acute  or  chronic, 
septic  or  non-septic,  in  their  character. 

Local  pericementitis  is  a  condition  of  inflammation  of  the  investing  root 
membrane  caused  by  traumatic  injury  or  septic  poisoning. 

Traumatic  pericementitis  may  be  induced  in  vital  teeth  by  blows,  falls,  or 
malocclusion,  either  from  the  natural  movement  of  the  teeth  incident  to 
the  loss  of  supporting  neighbors  or  by  fillings  which  have  not  been  prop- 


*  Dental  Pathology,  Therapeutics,  and  Pharmacology, 
t  American  System  of  Dentistry,  vol.  i.  p.  921. 

459 


460 


OPERATIVE   DENTISTRY. 


Fig.  571. 


eriy  shaped  to  give  a  perfect  occlusion  with  opposing  teeth  ;  by  the  press- 
ure of  an  ill-fitting  partial  set  of  artificial  teeth  ;  by  an  ill-fitting  crown  or 
by  an  improperly  adjusted  clasp  ;  by  excessive  malleting  and 
Fig.  570.     wedging  ;  by  ligatures  and  rubber-dam  clamps ;  by  the  rapid 
movement  of  teeth  in  the  operation  of  regulating  ;  by  the  pres- 
ence of  a  rubber  band  used  in  regulating,  and  which  has  been 
allowed  to  cut  its  way  towards  the  apex,  as  shown   in   Fig. 
570 ;  by  the  irritating  presence  of  salivary  calculus  upon  the 
roots ;  by  an  imperfect  root-filling,  or  by  puncturing  the  side 
of  the  root  with  drills  or  reamers. 
In  traumatic  pericementitis  the  inflammatory  condition  is  of  an  acute 
diffused  character,  seemingly  involving  the  whole  of  the  membrane  at  the 
same  time,  but  presenting  symptoms  which,  as  a  rule,  are  much  less  severe 
in  their  manifestations  than  those  associated  with  septic  conditions.     In  a 
majority  of  cases  of  traumatic  pericementitis  the  inflammatory  symptoms 
never  reach  the  stage  of  suppuration  and  involvement  of  surrounding  tis- 
sues.    In  the  severer  forms  of  injury,  such  as  blows  and  falls  upon  the 
teeth,  accompanied  by  laceration  of  the  overlying  tissues  or  partial  luxa- 
tion of  the  teeth,  induration  and  swelling  are  often  very  considerable, 
sometimes  ending  in  suppuration  from  infection  of  the  injured  tissues. 
Perforation  of  the  lateral  wall  of  the  canal  often  establishes  a  pericemen- 
titis which  resists  all  efforts  at  treat- 
ment.     Injuries,    however,    which    do 
not  cause  a  break  in  the  continuity  of 
the  tissues  do  not,  as  a  rule,  suppurate 
unless  the  pyogenic  organisms  are  al- 
ready in  the  system  and  are  deposited 
at  the  point  of  injury  from  the  blood- 
current.    Under  such  circumstances  the 
injured  tissues,  by  reason  of  their  low- 
ered vital  powers  of  resistance,  would 
furnish  a  favorable  soil  for  the  growth 
and  propagation  of  the  pyogenic  organ- 
isms, and  the  formation  of  pus  would  be 
the  result. 

Septic  pericementitis  may  be  either 
acute  or  chronic,  and  is  usually  the  sequel 
of  inflammation  and  gangrene  of  the 
pulp,  the  exceptions  being  such  cases 
as  those  just  mentioned.  Septic  peri- 
cementitis always  begins  as  a  circum- 
scribed inflammation,  located  at  the  apex 
of  the  root  of  the  tooth,  occasionally  in- 
volving one  or  more  teeth  upon  either 
side  of  it ;  the  tissues  first  involved  are  those  of  the  apical  space,  and  for 
this  reason  it  is  often  spoken  of  and  described  as  apical  pericementitis. 

Acute  apical  pericementitis  sometimes  accompanies  pulpitis ;  when  this 
dual  condition  is  manifest  in  double-  or  multiple-rooted  teeth,  it  is  possi- 


G         E      J    K 

A,  dental  pulp  and  its  artery  ;  B,  dentin  ;  C, 
tunica  propria  ;  D,  enamel ;  E,  pericementum  ; 
F,  cementum  ;  O,  canal  in  lower  jaw  ;  H,  dental 
artery;  J,  branch  of  dental  artery  supplying 
pericementum ;  A',  branch  of  dental  artery 
supplying  tunica  propria.    (After  Black.) 


DISEASES    OF    THE    PERICEMENTUM.  461 

ble  for  one  of  the  roots  to  contain  a  devitalized  pulp  while  the  other  por- 
tions are  vital ;  but  when  this  dual  condition  occurs  in  teeth  having  a  single 
root,  another  explanation  is  needed  to  account  for  the  phenomenon.  It 
seems  probable,  therefore,  that  inasmuch  as  the  vessels  of  both  the  pulp 
and  the  pericementum  arise  from  a  common  branch  located  at  the  apical 
space  (Fig,  571),  and  the  connective  tissue  which  enters  the  foramen  with 
the  vessels  and  nerve-trunk  is  continuous  with  the  pericementum  at  the 
apical  space,  the  inflammation  has  spread  by  continuity  of  structure. 

Acute  apical  pericementitis,  however,  is  not  always  of  septic  origin, 
for  it  may  be  the  result  of  chemic  irritation  from  the  escharotic  action  of 
arsenous  acid,  zinc  chloride,  carbolic  acid,  or  other  irritating  agents  which 
have  been  applied  to  the  pulp  or  to  the  canal  and  have  escaped  into  the 
apical  space.  Or  it  may  be  due  to  the  mechanic  irritation  of  portions  of 
filling- material  which  project  beyond  the  foramen  and  press  upon  the 
apical  tissues. 

Pathology. — Acute  apical  pericementitis  due  to  septic  infection  from 
a  gangrenous  pul^^  does  not  differ  materially  in  the  pathologic  changes 
which  take  place  in  its  tissues  from  those  which  are  observed  in  any  other 
tissue  which  may  be  the  seat  of  a  septic  inflammation. 

Irritation  at  the  apex  is  produced  by  infection  of  the  apical  tissues  with 
the  micro-organisms  of  supjiuration  or  of  their  waste  products,  or  with  the 
ptomaines  of  decomposition  produced  by  the  action  of  the  saprophytic 
organisms  upon  the  gangrenous  pulp.  At  the  beginning  the  irritation 
produces  hypersemia  of  the  vessels  of  the  pericementum,  especially  near 
the  ajDCx  of  the  root ;  this  is  followed  by  exudation  of  the  liquor  sanguinis 
and  the  migration  of  white  blood- corpuscles,  and  later  by  proliferation  of 
the  connective-tissue  cells.  The  pericementum  now  becomes  thickened, 
and  presents  areas  of  cloudiness.  Later  as  the  inflammation  progresses 
this  cloudiness  may  extend  over  the  entire  surface  of  the  membrane. 

At  this  stage,  if  the  cause  of  the  irritation  is  removed,  resolution  takes 
place  and  the  tissues  return  to  their  normal  state.  Failing  in  this,  the 
inflammatory  process  progresses,  and  the  morphologic  elements  surround- 
ing the  inflamed  part — the  leucocytes  and  the  embryonic  cells  formed 
from  the  fixed  tissue- cells — lose  their  vitality  and  are  converted  into  pus- 
corijuscles,  and  through  the  digestive  and  peptonizing  action  exerted  by 
the  pyogenic  organisms  upon  the  intercellular  substance  of  the  tissues  it 
is  liquefied  and  idus  is  formed,  resulting  in  dento-alveolar  abscess.  Occa- 
sionally the  inflammatory  process  is  conflned  to  the  apex  ;  at  others  it 
becomes  diffused  over  the  entire  membrane. 

Symptoms  and  Diagnosis. — The  flrst  symptom  noticed  in  acute 
pericementitis  of  septic  origin  is  a  gnawing,  uneasy  feeling  of  tension  in 
and  about  the  tooth,  with  a  desire  to  bite  upon  it.  This  feeling  of  tension 
is  produced  by  the  hypersemic  condition  of  the  blood-vessels  of  the  peri- 
dental membrane,  and  is  relieved  for  the  time  being  by  forcibly  biting 
upon  the  tooth.  Forcible  pressure  upon  the  teeth  drives  the  blood  out  of 
the  vessels  and  relieves  the  tension  for  a  few  minutes,  but  the  gnawing 
feeling  and  tension  again  return  in  a  slightly  increased  form.  Lateral  per- 
cussion of  the  tooth  reveals  slight  tenderness.     The  tooth  now  begins  to 


462  OPERATIVE    DENTISTRY.  -» 

feel  longer  than  the  others,  as  though  it  were  raised  from  the  alveolus,  and 
is  slightly  loose.  This  is  actually  the  fact,  for  as  the  congestion  of  the 
blood-vessels  goes  on  the  membrane  becomes  thickened  and  the  tooth  is 
slightly  raised  from  its  alveolus.  The  gum  around  the  tooth  becomes 
swollen  and  tender,  and  the  free  margins  assume  a  red  or  purple  hue. 
Pain  of  a  deep,  dull,  constant  character  will  now  be  present.  Lateral  per- 
cussion is  j)ainful,  and  forcibly  biting  upon  the  tooth,  instead  of  giving 
relief,  now  causes  intense  pain.  The  swelling  slowly  increases  and  the  pain 
is  still  deep-seated,  but  gradually  changing  to  a  dull,  throbbing  character, 
while  the  tooth  grows  more  and  more  sensitive  to  percussion. 

The  swelling  now  becomes  more  defined  and  palpation  will  discover  a 
softening  at  some  one  point  with  fluctuation,  which  indicates  the  forma- 
tion of  pus,  the  penetration  of  the  bone,  and  an  early  spontaneous  evacua- 
tion of  the  pus  by  natural  pointing,  or  it  may  escape  by  burrowing  along 
the  side  of  the  root,  finding  an  exit  at  the  margin  of  the  gum.  The  in- 
tensity of  the  symptoms  will  depend  somewhat  upon  the  character  of  the 
infection  and  upon  the  diathesis  of  the  patient. 

Differential  Diagnosis. — It  has  already  been  stated  that  pericemen- 
titis, next  to  pulpitis,  was  the  most  common  cause  of  toothache.  It  there- 
fore becomes  important  to  be  able  to  make  a  diagnosis  between  them.  At- 
tention has  also  been  called  to  the  fact  that  pulpitis  and  pericementitis  may 
occasionally  exist  at  the  same  time  in  an  individual  tooth  having  more 
than  one  root,  but  it  is  not  impossible  for  this  dual  condition  of  inflamma- 
tion to  exist  in  a  tooth  with  a  single  root.  Under  such  circumstances  the 
shai*p,  stinging,  lancinating  pain  of  a  pulpitis  may  be  present  and  asso- 
ciated with  soreness  to  percussion  and  elevation  of  the  tooth  in  the 
alveolus. 

In  a  large  majority  of  cases,  however,  pericementitis  is  not  developed 
until  after  the  vitality  of  the  pulp  has  been  destroyed  and  the  saiDrophytic 
germs  have  begun  their  work  of  reducing  the  gangrenous  pulp  to  its 
original  elements. 

The  ]pain  from  pulpitis  is  of  a  sharp,  stinging  character,  and  inclined  to 
be  paroxysmal  and  reflected  to  various  parts  of  the  face,  making  it  often 
difficult  to  locate  the  tooth  which  is  causing  the  pain.  The  normal  heat 
sense  is  also  greatly  lowered,  so  that  temperatures  which  can  be  borne  by  a 
healthy  tooth  become  intolerable  in  one  afl'ected  with  pulpitis.  While  in 
pericementitis  the  pain  is  always  located  in  the  affected  tooth,  and  is  of  a 
dull,  heavy,  gnawing  character.  The  heat  sense  in  pericementitis  is  raised 
somewhat  above  that  of  the  tooth  affected  with  pulpitis.  In  the  early 
stages  of  an  inflammation  cold  is  soothing,  as  it  contracts  the  blood-vessels 
and  retards  the  progress  of  hypersemia  and  exudation  ;  while  in  the  stage 
of  congestion  and  partial  stasis  heat  is  more  beneficial,  as  it  tends  to  pro- 
mote the  movement  of  the  blood,  particularly  in  the  congested  veins,  and 
thus  relieves  the  tension  upon  the  hyi)ersensitive  nerve-fibres  of  the  in- 
flamed tissues.  A  rigor  and  elevation  of  temperature  indicate  the  forma- 
tion of  pus. 

Prognosis. — The  usual  duration  of  acute  septic  apical  pericementitis  is 
from  three  days  to  two  weeks.     In  a  majority  of  these  cases  the  inflamma- 


DISEASES    OF   THE    PERICEMENTUM. 


463 


tion  ends  in  suppuration  and  the  formation  of  a  dento-alveolar  abscess,  occa- 
sionally they  terminate  in  resolution,  while  in  others  the  cell  proliferation 
results  in  the  formation  of  new  cement-tissue, — hypercementosis.  The 
latter  condition  is  the  result  of  a  continuation  of  the  irritation  that  de- 
veloped the  acute  attack,  but  which  is  of  a  milder  type,  assuming  a  sub- 
acute or  chronic  form. 

Local  Treatment. — The  local  treatment  of  acute  pericementitis  of 
either  the  traumatic  or  septic  form  is,  first,  to  remove  the  cause  of  the  irri- 
tation if  it  still  exists.  This  comprehends,  in  the  traumatic  variety,  the 
relief  of  malocclusions,  the  discarding  of  ill-fitting  plates  or  crowns  and 
improperly  adjusted  clasps,  the  removal  of  salivary  calculus,  or  of  root- 
fillings  which  are  causing  pressure  upon  the  apical  space.  In  the  septic 
variety  it  means  the  opening  of  the  pulp-canal  and  the  removal  of  its 
decomposing  contents,  either  by  chemic  means — treatment  with  sodium 
dioxide  solution— or  by  mechanic  means,  in  the  use  of  broaches,  barbed 
cleansers,  etc.,  exercising  the  greatest  care  not  to  allow  the  broach  or 
Donaldson  cleanser  to  pass  the  apical  foramen  or  to  force  the  septic 
material  into   the  apical    space.      Frequent    irrigation    with    antiseptic 

Fig.  572. 


Dunn  capillary  or  drop  syringe. 


solutions  should  accompany  the  process  of  cleansing  the  canals,  followed 
by  the  application  of  hydrogen  dioxide,  either  upon  a  pledget  of  cotton  or 
by  the  aid  of  the  Dunn  syringe  (Fig.  572).  After  the  canals  have  been 
thoroughly  cleansed,  thej^  should  be  dressed  with  one  of  the  essential  oils 
or  Dr.  Black's  one-two-three  mixture  : 


or, 


R   Oil  of  cinnamon,  1  part  ; 
Carbolic  acid,  2  parts  ; 
Oil  of  wintergreen,  3  parts  ; 

R  Eugenol,  1  part ; 

Carbolic  acid,  2  parts  ; 
Eucalyptol,  3  parts ; 

or  with  some  other  suitable  antiseptic. 

In  opening  the  canals  of  teeth  which  are  very  sore  the  tooth  should  be 
supported  with  the  thumb  and  index-finger  of  the  left  hand  while  drilling 
through  the  overlying  dentinal  tissue  or  the  filling,  as  the  case  may  be. 
Or  a  ligature  may  be  tied  around  the  cervix  of  the  tooth,  the  ends  being 
left  long  enough  to  extend  well  beyond  the  mouth,  and  traction  made  upon 
it,  as  suggested  by  Dr.  J.  Foster  Flagg,  to  counteract  the  pressure  of  the 


464  OPEEA.TIVE    DENTISTRY. 

drill.  The  immediate  opening  of  the  canals  is  imperative  in  all  cases 
where  the  pulp  has  died  under  a  filling,  otherwise  the  accumulation  of  the 
mephitic  gases  will  force  the  septic  material  contained  in  the  pulp-canal 
into  the  apical  space  and  establish  an  acute  alveolar  abscess.  Such  teeth 
do  better  if  left  open  for  from  twenty-four  to  forty-eight  hoflrs  than  they  do 
if  dressings  are  applied.  If  left  open,  the  gases  of  decomposition  readily 
escape,  while  if  the  opening  is  closed,  they  rapidly  accumulate  and  keep 
up  the  irritation. 

Secondly,  to  secure  rest  for  the  tooth  by  preventing  the  opposing  tooth 
from  occluding  with  it.     This  may  be  done  by  moulding  a  piece  of  base- 
plate gutta-xDcrcha  to  the  crowns  of  the  lower  bicuspid  and 
Fig.  573.  molar  teeth  upon  the  opposite  side  of  the  mouth,  or  the 

adjustment  of  a  metal  cap,  as  shown  in  Fig.  573,  so  that 
when  the  teeth  are  closed  they  rest  upon  the  gutta-percha 
splint  or  the  metal  cap.  Or,  if  there  are  no  teeth  remain- 
ing upon  the  opposite  side,  a  tooth  in  front  or  behind  the 
Metal  cap.  affcctcd  One  may  be  utilized  for  the  purpose.     Or  a  hollow 

rubber  crown,  made  by  the  S.  S.  White  Company,  may  be 
placed  ux)on  a  tooth  in  a  suitable  location.  A  still  more  simple  and  ef- 
ficient method  is  to  dry  the  morsal  surface  of  two  or  three  teeth  upon  the 
same  side  of  the  mouth,  preferably  the  lower  teeth,  and  cover  them  with 
zinc  oxyphosphate  cement.  The  writer  prefers  Ames's  metaloid  for  this 
purpose  to  any  other,  on  account  of  its  great  adhesive  qualities. 

After  rest  has  been  secured,  the  third  step  in  the  treatment  is  the  ex- 
hibition of  topical  remedies  for  the  relief  of  the  pain  and  -controlling  or 
aborting  the  inflammatory  symptoms.  The  local  congestion  may  be  re- 
lieved by  freely  scarifying  the  gum  over  the  affected  tooth,  and  promoting 
the  bleeding  by  the  free  use  of  warm  water.  Or  counterirritation  may  be 
employed  by  painting  the  gum  with  cantharidal  collodion  or  with  the 
following  combination  of  remedies  : 

R  Tincture  of  aconite, 
Tincture  of  iodine, 
Spirits  of  chloroform, 
Spirits  of  camphor,  aa  f  3  i.     M. 

Darby' s  capsicum  and  sinapin  dental  plasters  will  also  be  found  beneficial 
in  deflecting  the  blood  to  the  surface,  if  applied  to  the  gum  directly  over 
the  affected  tooth.  The  hot- water  bag  applied  to  the  side  of  the  face  is 
often  very  soothing  in  the  more  advanced  stage  of  the  inflammation.  It 
should  be  wrapped  in  a  towel  or  covered  with  several  thicknesses  of 
flannel,  to  conserve  the  heat  and  to  furnish  an  agreeable  surface  upon 
which  to  rest  the  face. 

Constitutional  Treatment. — The  throbbing  pain  may  often  be 
greatly  relieved  by  the  use  of  a  hot  foot-bath  to  which  a  tablespoonful  or 
two  of  mustard  has  been  added.  This  equalizes  the  circulation  hy  causing 
a  determination  of  blood  to  the  lower  extremities,  and  relieves  arterial 
tension  in  the  upper  part  of  the  body,  and  by  that  process  mitigates  the 
pain.     A  brisk  saline  laxative  is  also  beneficial  in  many  cases. 


DISEASES    OF    THE    PERICEMENTUM.  465 

In  the  more  severe  cases,  accompanied  with,  febrile  symptoms,  full 
bounding  pulse  and  high  temperature,  coated  tongue,  constipation,  head- 
ache, and  chilliness,  efforts  are  still  to  be  made  to  abort  the  inflammation. 
Quinine  in  doses  of  from  five  to  ten  grains  may  be  administered,  or  some 
of  the  coal-tar  derivatives,  like  pheuacetine  or  antikamnia,  may  be  em- 
ployed in  five-  to  ten-grain  doses  until  the  excessive  rapidity  of  the  pulse 
is  controlled  and  the  pain  rendered  less  severe.  If  the  inflammatory 
symptoms  are  not  markedly  less  by  bedtime,  ten  to  fifteen  grains  of 
Dover's  powder  may  be  administered  with  a  hot  lemonade  or  other  hot 
drink,  and  the  patient,  after  a  hot  foot-bath,  placed  in  bed  and  covered 
with  an  extra  blanket  in  order  to  promote  copious  diaphoresis. 

Or  bromide  of  potassium,  fifteen  to  twenty-five  grains,  combined  with 
tincture  of  veratrum  viride,  five  minims,  may  be  administered,  and  repeated 
in  four  hours  if  needed. 

Constipation  may  be  relieved  by  taking  in  the  morning  before 
breaking  the  fast  a  glass  of  Hunyadi  water  or  one-half  ounce  of  sulphate 
of  magnesia  in  a  glass  of  water,  or  a  grain  of  calomel  may  be  adminis- 
tered at  bedtime,  omitting  the  lemonade,  and  following  it  in  the  morning 
with  a  Seidlitz  powder. 

Some  operators  have  great  faith  in  the  constitutional  effect  of  calcium 
sulphide  in  limiting  the  suppurative  process.  Its  use  is,  however,  some- 
what empirical,  as  there  is  no  definite  knowledge  of  its  physiologic  action 
upon  the  tissues.  The  theory  has  been  advanced,  and  the  results  seem  to 
prove  the  theory,  that  it  has,  first.,  a  stimulating  effect  upon  the  blood- 
current  and  glandular  elements  of  the  mucous  membrane  and  the  skin ; 
secondly.,  this  stimulating  effect  is  noticed  in  the  increased  movement  of  the 
blood-current  and  in  the  amount  of  normal  glandular  secretions,  while  it 
checks  that  due  to  venous  congestion  and  blood  stasis  j  thirdly,  it  is  thought 
to  produce  H.^S  in  the  system,  which  has  a  controlling  or  restraining  influ- 
ence upon  the  amseboid  movements  of  the  wandering  cells  or  leucocytes. 

SUBACUTE   AND   CHRONIC   PERICEMENTITIS. 

These  conditions  present  all  of  the  characteristics  of  the  acute  form  of 
the  disease,  but  in  a  less  severe  form. 

The  most  common  cause  of  subacute  and  chronic  pericementitis  is  a 
septic  condition  of  the  pulp-canals,  sometimes  resulting  in  pericemental 
soreness  only,  or  in  the  formation  of  pus.  These  forms  of  pericementitis 
are  usually  the  sequelae  of  acute  attacks  of  the  affection.  They  may  also 
occur  in  teeth  in  which  the  pulps  have  been  removed  and  the  canals  filled, 
but  this  condition  is  usually  found  associated  wdth  crooked  roots  or  con- 
tractions of  the  caliber  of  the  canals  which  have  prevented  the  complete 
removal  of  the  pulp  to  the  apical  foramen  ;  or  they  may  be  caused  by  sei^tic 
conditions  from  a  pulp  which  has  died  under  a  filling ;  and  occasionally 
they  are  found  associated  with  apparently  sound  teeth  that  have  suffered 
from  some  traumatic  injury  which  caused  death  of  the  pulp,  but  which  for 
a  long  period  gave  no  trouble  ;  or  with  teeth  whose  pulp  vitality  has  been 
lost  through  the  plugging  of  the  artery  of  supply  by  a  thrombus,  and  fatty 
degeneration  has  taken  place  in  the  tissues  of  the  pulp.     In  a  considerable 

30 


466  OPERATIVE    DENTISTRY. 

number  of  cases  of  subacute  and  chronic  pericementitis  there  is  no  evidence 
whatever  of  the  formation  of  pus,  or  even  of  swelling  of  the  overlying 
gum-tissue.  This  is  true  of  even  some  of  the  septic  cases.  It  would  seem, 
therefore,  from  this  that  the  character  of  the  septic  organisms  was  less 
virulent  than  during  the  acute  attack,  or  that  the  tissues  are  more  resistant 
to  the  action  of  the  organisms  or  their  waste  products,  or  perhaps  both  of 
these  suppositions  are  true,  and  for  that  reason  the  inflammatory  j)rocess 
runs  a  less  vigorous  course. 

Symptoms. — In  chronic  apical  pericementitis  the  patient  usually 
complains  of  periodical  soreness,  which  lasts  for  a  day  or  two,  or  perhaps 
for  three  or  four  days ;  the  soreness  then  disappears  to  return  again  after 
a  shorter  or  longer  interval.  In  some  of  these  cases  the  gum  will  be 
markedly  congested,  in  others  no  discoverable  change  in  the  color  of  the 
gum  takes  place.  Percussion  is  more  or  less  painful,  and  palpation  over 
the  apex  of  the  root  often  gives  evidence  of  tenderness.  The  tooth  is  not 
sensitive  to  changes  of  temperature. 

Marked  sensitiveness  to  changes  of  temperature  would  indicate  hyper- 
sensitive dentin  or  inflammation  of  the  pulp,  and  should  exclude  i^erice- 
mentitis  from  the  diagnosis.  Upon  close  examination  of  some  of  these 
cases  a  very  slight  discharge  of  pus  may  be  discovered  at  the  cervix  of  the 
tooth,  and  if  a  fine  probe  is  passed  into  the  opening  from  which  the  pus 
can  be  pressed,  it  will  follow  a  sinus  or  open  track  which  the  pus  has  made 
for  itself  at  the  side  of  the  root  down  to  the  apex. 

Treatment. — Many  cases  of  chronic  pericementitis  are  dependent  for 
their  origin  upon  traumatic  injuries  like  malocclusions  due  to  the  natural 
movement  of  the  teeth  towards  each  other  after  a  supporting  neighbor  has 
been  lost.  The  malocclusion  may  be  one  in  which  the  pressure  upon  the 
tooth  is  too  great,  or  it  may  be  in  a  wrong  direction,  forcing  it  into  an 
abnormal  position.  The  tooth  is  often  slightly  loose  and  sore  to  pressure 
or  percussion.  Or  the  malocclusion  may  be  caused  by  a  filling  which  has 
not  been  jDroperly  occluded  to  the  morsal  surface  of  the  antagonizing  tooth. 
In  either  case  the  tooth  or  the  filling  should  be  cut  away  until  a  natural  or 
comfortable  occlusion  has  been  restored,  when,  by  the  aid  of  the  local 
application  of  the  aconite  and  iodine  preparation  to  the  gum  over  the  apex 
of  the  tooth,  the  soreness  and  looseness  will  soon  disappear. 

Devitalized  teeth  which  have  had  their  pulp-canals  filled  furnish  a 
considerable  number  of  mild  septic  cases  which  result  in  chronic  perice- 
mentitis. This  is  due  sometimes  to  imperfect  sterilization  of  the  dentin,  or 
of  fragments  of  pulp  left  in  tortuous  canals  and  crooked  roots  ;  at  others  to 
imperfect  methods  of  cleansing  and  filling  the  canals,  or  of  forcing  portions 
of  the  filling-material  beyond  the  foramen.  In  all  such  cases  the  root- 
filling  should  be  removed,  and  the  oi^eration  of  cleansing  the  canals, 
sterilization,  and  filling  done  over  again,  as  this  is  the  only  way  in  which 
it  is  possible  to  secure  restoration  of  health  to  the  tooth. 

The  difficulties  are  such  sometimes,  however,  on  account  of  the  mal- 
formation of  the  roots,  that  it  becomes  impossible  to  completely  sterilize 
the  canals  and  restore  the  tooth  to  a  healthy  condition,  even  after  repeated 
trials  of  resterilization  and  filling.     Under  such  circumstances  the  extrac- 


DISEASES    OF    THE    PERICEMENTUM.  467 

tion  of  the  tooth  is  the  only  way  out  of  the  difficnltj'^,  and  this  is  to  be 
advised  rather  than  to  allow  the  tooth  to  remain  as  a  constant  source  of 
irritation. 

GENERAL  NON-SEPTIC  PERICEMENTITIS. 

General  or  constitutional  non- septic  pericementitis  is  an  inflammation 
of  the  pericementum  involving  a  number  of  teeth  at  the  same  time  in  one 
or  both  jaws,  and  dependent  upon  certain  specific  systemic  conditions, 
such  as  rheumatism  and  gout,  tubercular  conditions,  scorbutus,  diabetes 
mellitus,  and  albuminuria,  or  to  the  local  toxic  manifestations  of  certain 
drugs  like  mercury,  iodine,  and  phosphorus,  and  the  preparations  of  gold, 
copper,  antimony,  arsenic,  etc. 

The  pathologic  changes  which  take  place  in  non-septic  pericementitis 
due  to  systemic  conditions  are  in  general  the  same  as  are  found  in  those 
cases  which  are  dependent  upon  local  causes  for  their  origin.  But  the 
exudations  are  much  more  liable  to  become  organized  into  new  tissue,  re- 
sulting in  hypercementosis. 

The  tendency  of  acute  local  pericementitis  is,  from  the  severity  of  the 
inflammation,  to  produce  death  of  the  exuded  leucocytes  and  the  embryonic 
cells  formed  from  the  fixed  tissue-cells — necrobiosis — and  the  formation 
of  pus.  While  in  certain  forms  of  systemic  or  general  pericementitis  the 
tendency  is  strongly  to  the  formation  of  new  tissue,  through  the  organization 
of  the  escaped  leucocytes  and  the  embryonic  cells.  This  tendency  is  most 
often  noticed  in  that  form  of  pericementitis  due  to  the  specific  action  of 
gout  and  rheumatism.  On  the  other  hand,  when  the  inflammation  is  due 
to  certain  other  systemic  conditions  like  tuberculosis,  scorbutus,  diabetes 
mellitus,  albuminuria,  and  mercurial  ptyalism,  the  tendency  is  in  the 
direction  of  necrobiosis  and  the  formation  of  pus. 

Bhemnatic  and  gouty  pericementitis  is  rarely  general  in  its  character.  Its 
most  frequent  manifestations  are  decidedly  local  in  the  sense  that  only  a 
few  teeth  are  involved  at  the  same  time,  although  occasionally  all  of  the 
teeth  may  be  the  seat  of  inflammatory  symptoms  due  to  these  causes. 

Clinical  and  x^ost- mortem  experience  teaches  that  the  materies  morbi  of 
these  diseases  has  a  predilection  for  the  fibrous  structures  of  the  body, 
especially  the  synovial  membranes,  the  aponeuroses  of  muscles,  the  dura 
mater,  the  cardiac  tissues,  and  the  periosteal  and  pericemental  membranes. 
The  structure  most  commonly  affected  is  the  synovial  membrane,  resulting 
in  inflammatory  conditions  of  the  joints. 

It  not  uncommonly  happens,  however,  that  there  is  associated  with  the 
inflammatory  phenomena  of  the  joints  enlargements  of  the  long  bones  and 
nodular  formations  in  other  localities,  while  conditions  somewhat  analogous 
are  often  presented  in  the  pericementum. 

The  predisposing  and  exciting  causes  of  certain  irritative  conditions  of 
the  pericementum  seem  to  have  their  origin  in  the  same  conditions  which 
bring  about  the  phenomenon  of  rheumatism  and  gout,  and  they  have  also 
proved  by  experience  to  be  amenable,  in  many  cases,  to  the  same  specific 
treatment  adopted  in  these  diseases.  It  is  a  notable  fact,  also,  that  in 
persons  suifering  from  this  form  of  pericementitis  the  urine,  saliva,  and 
perspiration  nearly  always  give  a  decidedly  acid  reaction.     Serumal  de- 


468  OPERATIVE   PENTISTRY. 

posits  sometimes  form  upon  the  root  of  the  tooth  near  the  apex  when  there 
is  no  connection  between  the  deposit  and  the  mouth.  Under  such  circum- 
stances suppuration  often  supervenes,  and  produces  a  form  of  pyorrhoea 
alveolaris. 

The  pericementum  seems  to  be  very  susceptible  to  the  irritating  effects 
of  an  acid  condition  of  the  blood,  whether  from  an  excess  of  lactic  or 
uric  acid  retained  in  the  system  or  from  such  acids  as  are  found  in  sour 
wines  and  malt  liquors.  The  habitual  use  of  sour  wines  and  malt  liquors 
by  those  having  the  rheumatic  and  gouty  diathesis  greatly  aggravates 
these  conditions,  and  some  individuals  are  so  susceptible  to  their  irritating 
influence  that  a  slight  indulgence  will  often  precipitate  an  attack  of  acute 
articular  rheumatism,  of  gout,  or  of  pericementitis. 

General  pericementitis  of  a  mild  form  is  often  the  forerunner  of  an 
acute  attack  of  rheumatism  or  gout ;  while,  upon  the  other  hand,  a  general 
or  a  local  pericementitis,  involving  a  number  of  teeth  in  different  parts  of 
the  mouth,  may  be  the  only  manifestation  or  expression  of  the  presence  of 
the  rheumatic  or  gouty  diathesis. 

Congestion  and  thickening  of  the  pericementum  and  temporary  loosen- 
ing of  the  teeth,  and  occasionally  death  of  the  pulp,  accompanied  by  dull, 
gnawing  pains  and  more  or  less  soreness,  are  a  not  infrequent  occurrence 
in  attacks  of  rheumatism  and  gout. 

Symptoms  and  Diagnosis. — In  rheumatic  and  gouty  pericemen- 
titis soreness  and  pain  in  the  teeth  are  early  symptoms,  and  generally 
associated  with  an  acid  condition  of  the  salivary  secretions,  of  the  perspi- 
ration, and  of  the  urine  ;  while  it  is  not  at  all  uncommon  to  find  the  indi- 
vidual at  the  same  time  suffering  from  muscular  pains  which  are  unmis- 
takably rheumatic  in  character,  or  from  an  acute  arthritis  of  one  or  more 
joints  of  the  extremities.  Sometimes,  however,  the  only  manifestations 
of  the  rheumatic  and  gouty  conditions  are  the  soreness  and  painful  condi- 
tion of  the  teeth  and  the  acid  condition  of  the  saliva  and  the  urine. 

Eheumatic  and  gouty  pericementitis,  like  rheumatism  and  gout  in  gen- 
eral, may  be  acute  or  chronic  in  their  manifestations.  The  acute  form  is 
usually  establisl^ed  as  the  result  of  taking  cold  or  of  over-indulgence  in 
the  pleasures  of  the  table,  and  like  those  general  conditions  is  greatly  ag- 
gravated by  bad  weather,  a  low  barometer,  and  excesses  in  eating  and 
drinking.  The  chronic  form  of  the  disease  is  the  result  of  repeated  attacks 
of  the  acute  form,  and  most  often  terminates  in  hypercementosis. 

Soreness  of  the  teeth  to  pressure,  as  in  mastication,  is  the  first  symp- 
tom of  acute  rheumatic  and  gouty  pericementitis.  This  condition  is  at  first 
relieved  by  continued  pressure,  and  the  individual  desires  to  close  the 
teeth  together  and  keep  them  in  this  iDOsition.  After  a  few  hours  the  teeth 
become  painful  to  such  pressure,  and  constant  effort  is  made  to  prevent 
the  teeth  from  coming  forcibly  in  contact.  Mastication  then  becomes  very 
painful  or  impossible,  and  liquid  food  only  can  be  taken.  The  gums  be- 
come more  or  less  congested  and  purplish  in  color,  but  suppuration  rarely 
takes  place  except  ichere  concretions  have  been  formed  upon  the  roots.  When 
the  disease  is  confined  to  a  few  teeth  in  a  single  location  or  in  different 
parts  of  the  mouth,  they  have  the  feeling  of  being  loose  and  considerably 


DISEASES   OF   THE   PERICEMENTUM.  469 

elongated.  This  is  due  to  the  congestion  and  thickening  of  the  i)erice- 
mentum,  which  lifts  the  teeth  from  their  alveoli  and  makes  them  loose. 

Differential  Diagnosis. — Difficulty  is  sometimes  experienced  in  diag- 
nosing between  a  rheumatic  or  gouty  pericementitis  and  an  incipient  or 
chronic  aj)ical  pericementitis  due  to  septic  conditions.  These  difficulties 
arise  from  the  fact  that  pulpless  teeth  are  much  more  liable  to  become  the 
seat  of  rheumatic  symptoms  than  normal  teeth,  consequently,  when  several 
devitalized  teeth  become  the  seat  of  pericementitis,  it  is  almost  impossible 
in  the  early  stage  to  diagnosticate  between  them  except  by  inference.  The 
fact,  however,  remains  that  in  a  rheumatic  pericementitis  several  teeth  are 
almost  invariably  affected  at  the  same  time,  while  in  septic  apical  perice- 
mentitis a  single  tooth  is  usually  at  fault.  Should  three  or  four  devitalized 
teeth  be  in  a  state  of  septic  apical  inflammation  at  the  same  time,  the  diag- 
nosis could  be  proved  by  the  absence  of  the  other  symptoms  which  usually 
accompany  an  attack  of  rheumatic  pericementitis.  The  duration  of  the 
symptoms  will  vary  from  three  or  four  days  to  as  many  weeks,  depending  upon 
the  severity  of  the  attack  and  the  success  of  the  constitutional  treatment. 

Prognosis. — The  prognosis  in  this  form  of  pericementitis  is  generally 
good,  for  the  reason  that  the  acute  symptoms  are  usually  controlled  by 
systemic  treatment.  In  the  chronic  form  of  the  disease  the  prognosis  is 
less  favorable,  as  hypercementosis  is  the  usual  sequel,  and  systemic  treat- 
ment has  little  or  no  effect  upon  the  progress  of  new-tissue  formation. 

Treatment. — The  treatment  of  these  forms  of  pericementitis  is  largely 
systemic,  and  is  comprehended  in  the  regular  methods  employed  in  general 
rheumatic  and  gouty  conditions, — viz.,  the  exhibition  of  such  remedies  or 
combination  of  remedies  as  have  for  their  base  salicylic  acid  or  colchicum, 
or  both,  mercurial  and  iodine  compounds,  lithia,  various  mineral  waters, 
hot  mineral  baths,  and  Turkish  baths.  A  restricted  diet  which  reduces 
the  quantity  of  meat  consumed  and  cuts  off  all  game,  wine,  and  malt 
liquors,  is  also  beneficial. 

Local  treatment  in  the  form  of  depletion  to  directly  relieve  the  con- 
gested condition  of  the  gums,  and  indirectly  of  the  pericementum,  often 
gives  relief  after  a  little  time.  This  may  be  obtained  by  scarifying  the 
gums  and  promoting  bleeding  by  the  use  of  tepid  water  held  in  the  mouth. 
Or  these  symptoms  may  be  relieved  by  counter-irritation,  as  already  de- 
scribed upon  a  preceding  page.  If  suppuration  be  present,  the  pockets 
should  be  explored  for  calcic  deposits,  and  if  discovered,  they  should  be 
removed  and  the  pockets  treated  with  dilute  sulphuric  acid,  trichloracetic 
acid,  or  other  stimulating  and  antiseptic  applications.  For  further 
methods  of  treatment  of  this  form  of  the  disease  the  reader  is  referred  to 
the  chapter  on  '^  Pyorrhoea  Alveolaris." 

TUBEECULAE,   PERICEMENTITIS. 

Pericementitis  occurring  in  an  individual  of  tubercular  diathesis  runs 
such  a  peculiar  and  rapid  course  that  it  deserves  separate  mention.  Al- 
though, strictly  speaking,  the  term  as  above  applied  may  not  be,  perhaps, 
correctly  used,  it  nevertheless  serves  to  describe  a  condition  by  no  means 
uncommon,  and  which  sometimes  has  serious  consequences. 


470  OPERATIVE    DENTISTRY. 

In  using  this  term  it  is  not  intended  to  imply  that  the  form  of  peri- 
cementitis to  be  described  is  due  to  the  presence  of,  or  originates  in,  the 
tuberculous  condition,  or  that  the  tubercle  bacilli  are  the  cause  of  the 
peculiar  and  rapid  course  of  the  disease. 

In  all  of  the  cases  which  have  come  under  the  observation  of  the  writer, 
the  primary  cause  of  the  affection  was  a  traumatic  injury  of  the  pericemen- 
tum, produced  l:)y  either  excessive  malleting,  as  in  large  contouring  opera- 
tions, the  rapid  movement  of  the  teeth,  or  a  malocclusion.  In  all  of  the  cases 
the  patient  gave  unmistakable  evidences  of  having  a  tuberculous  diathesis. 
It  is  generally  conceded  to  be  a  clinical  fact  that  injuries  occurring  in 
tubercular  subjects  are  much  more  prone  to  end  in  supi3uration  than  are 
like  injuries  in  other  persons,  and  that  the  inflammatory  i3rocess  is  much 
more  acute  than  in  other  individuals. 

The  following  case,  which  is  introduced  by  way  of  illustration,  occurred 
in  the  practice  of  the  writer.  The  patient  was  a  college  student  for  whom 
he  had  made  two  large  countour  fillings  with  gold  in  approximating  cavi- 
ties in  the  right  superior  bicuspids.  The  operations  had  consumed  four 
hours  of  time  in  the  preparation  of  the  cavities  and  inserting  and  finish- 
ing the  fillings.  The  teeth  were  vital,  and  the  hand-mallet  was  used  in 
condensing  the  gold.  In  a  few  hours  after  the  operation  the  teeth  became 
very  sore  and  painful,  and  at  the  end  of  twenty-four  hours  the  face  was 
greatly  swollen  and  the  gums  tumefied,  soft,  and  boggy  from  the  lateral  in- 
cisor of  the  right  side  back  to  and  including  the  second  molar.  The  teeth 
thus  involved  were  all  loose  and  exceedingly  sensitive  to  pressure  or  percus- 
sion. On  lancing  the  gums,  which  was  done  in  several  places,  thick  creamy 
pus  was  discharged  in  great  quantity,  and  upon  irrigating  the  pus-cavity  it 
was  found  to  be  continuous  through  the  whole  extent  of  the  inflamed  area. 
The  periosteum  was  also  lifted  from  the  external  plate  of  the  alveolar  pro- 
cess, but  higher  up  over  the  bicuspids  than  the  other  teeth.  The  abscess 
continued  to  discharge  for  several  weeks,  but  finally  closed  without  necrosis 
of  the  bone.    The  teeth  all  became  firm  in  their  alveoli  and  remained  vital. 

Other  cases  of  a  similar  nature  occurring  from  various  injuries  in  which 
necrosis  of  the  external  alveolar  plate  resulted  from  the  inflammation 
might  be  described,  but  this  is  sufficient  for  the  purpose  of  illustration. 

SCORBUTIC   PERICEMENTITIS. 

This  form  of  pericementitis  is  one  of  the  marked  symptoms  of  scurvy. 
It  is  the  result  of  long  exposure  to  a  cold  and  damp  atmosphere,  coarse 
diet,  insufiicient  vegetable  food,  and  fatiguing  labor.  It  most  frequently 
occurs  among  sailors  of  the  Arctic  regions,  particularly  whalers.  It  is 
also  seen  among  soldiers  and  the  men  of  lumber  camps.  It  is  not  infre- 
quently seen  in  our  large  cities  among  the  very  jDOor,  who  are  housed  in 
damp  basements  and  cellars,  and  whose  food-supply  is  very  scanty  and  of 
the  least  nutritious  varieties. 

Occasionally  little  children  under  two  years  of  age  are  victims  of  the 
disease,  and  this  is  an  evidence  of  malnutrition. 

Symptoms  and  Diagnosis. — Scorbutic  pericementitis,  as  a  rule, 
attacks  all  of  the  teeth  in  rapid  succession,  and  is  therefore  a  general 


DISEASES    OF    THE   PERICEMENTUM.  471 

pericementitis.  In  a  typical  case  of  scurvy  the  teeth  are  all  loose,  sore, 
and  painful,  making  mastication  impossible.  The  gums  ai'e  swollen  and 
spongy,  purplish  in  color,  and  bleed  easily,  while  pus  exudes  around  their 
margins  and  from  the  dental  alveoli.  The  breath  is  fetid  and  sometimes 
there  is  an  increased  flow  of  saliva.  Associated  with  the  oral  symptoms 
there  are  certain  manifestations  of  the  disease  upon  the  skin  in  the  form 
of  livid  spots  intermixed  with  spots  of  a  less  vivid  color.  These  spots  are 
SQiall  and  resemble  flea-bites.  They  sometimes  occur  in  patches  or  in 
strips  and  are  usually  located  at  the  roots  of  the  hair  ;  they  are  scattered 
over  the  chest,  thighs,  arms,  and  trunk,  and  are  occasionally  seen  upon  the 
mucous  membrane  of  the  mouth  and  nasal  passages.  The  disease  is  ac- 
companied by  extreme  weakness,  general  debility,  and  depression  of 
spirits.  Occasionally  there  is  severe  pain  in  the  extremities,  particularly 
in  the  wrists  and  ankles.  In  the  severer  form  of  the  disease,  hemor- 
rhage occurs  from  the  livid  spots  found  upon  the  skin  {purpura  hcemor- 
rhagica),  and  from  the  spots  found  upon  the  mucous  membrane  of  the 
mouth  and  nose.  In  many  of  these  cases  there  is  a  considerable  deposit 
of  salivary  calculus  about  the  cervices  of  the  teeth. 

Treatment. — The  treatment  of  scurvy  calls  for  a  radical  change  in  the 
sanitary  surroundings  of  the  patient.  A  generous  diet,  supplemented 
with  green  vegetables  and  acid  fruits,  is  generally  all  that  is  required  in 
the  way  of  general  treatment.  In  the  severer  cases  tonics  are  called  for, 
like  the  elixir  of  calisaya,  strychnine  and  iron,  or  quinine. 

The  local  treatment  for  the  inflammatory  conditions  of  the  teeth  and 
gums  would  be  to  cleanse  the  mouth  by  the  use  of  hydrogen  dioxide,  re- 
move all  deposits  of  soft  debris  and  salivary  calculus  from  the  teeth,  relieve 
the  congestion  of  the  gums  by  painting  them  with  the  tincture  of  aconite 
and  iodine,  equal  parts,  or  by  scarifying  them  with  a  sharp  lancet,  and 
prescribing  an  antiseptic  and  astringent  mouth  lotion.  In  indolent  and 
ulcerative  conditions  the  gums  may  be  painted  with  a  ten  per  cent,  solu- 
tion of  zinc  chloride  in  water. 

General  x)ericementitis  is  often  a  progressive  symptom  in  diabetes  mel- 
litus,  Brighfs  disease,  and  locomotor  ataxia.  The  conditions  which  are  pre- 
sented are  similar  to  those  which  will  be  described  later  under  the  head  of 
pyorrhoea  alveolaris,  with  the  exception  that  the  roots  of  the  teeth  when 
finally  exuviated  do  not  usually  show  any  signs  of  serumal  deposits. 

MERCURIAL   PERICEMENTITIS. 

This  form  of  the  disease  is  due  to  the  constitutional  imj)ression  of 
mercury.  Mercurial  ptyalism  with  its  attendant  evils  has  been  so  common 
in  the  past  that  almost  every  practitioner  of  twenty-five  years'  experience 
saw  many  cases  in  the  early  days  of  his  practice.  But  happily  in  these 
later  years  the  use  of  the  drug  has  been  greatly  restricted,  so  that  at  the 
present  time  such  cases  are  rarely  seen  except  in  the  Southern  States. 

The  effects  which  are  produced  by  mercury  upon  the  general  system, 
and  locally  in  the  mouth,  depend  upon  the  quantity  administered  and  the 
susceptibility  of  the  individual  to  the  action  of  the  drug.  Children  be- 
tween the  ages  of  five  and  ten  years  are  peculiarly  susceptible.     There  is, 


472  OPERATIVE    DENTISTRY. 

however,  a  very  great  difference  in  the  susceptibility  of  various  individ- 
uals ;  in  one  an  ordinary  dose  of  blue  pill  or  of  calomel  will  produce  a  severe 
general  pericementitis,  inflamed  gums,  profuse  salivation,  and  swollen 
tongue,  while  another  seems  to  be  almost  proof  against  its  action,  even  in 
large  and  repeated  doses. 

Garretson  records  a  case  of  mercurial  poisoning  in  a  child  seven  years 
of  age  in  which  the  administration  of  three  grains  of  calomel  resulted  in 
the  loss  by  necrosis  of  the  left  half  of  the  lower  jaw. 

The  writer  has  recorded  a  case  ^  of  a  woman  thirty  years  of  age  in 
which  fifteen  grains  of  calomel  taken  in  three-grain  doses  at  bedtime  pro- 
duced necrosis  of  both  jaws,  accompanied  by  extensive  sloughing  of  the 
gums  of  the  inferior  maxilla  and  of  the  soft  tissues  covering  the  roof  of 
the  mouth,  swollen  tongue,  intolerable  fetid  breath,  excessive  salivary  se- 
cretion, loosened  teeth,  and  an  uncontrollable  diarrhoea,  the  case  ending  in 
death  from  exhaustion. 

Various  other  drugs,  such  as  potassium  iodide,  pilocarpin,  the  prepara- 
tions of  gold,  copper,  antimony,  arsenic,  etc.,  are  capable  of  producing 
ptyalism  ;  and  if  this  condition  is  maintained  for  any  considerable  period, 
the  pericementum  becomes  involved,  resulting  in  inflammation  of  this 
membrane,  suppuration,  and  possible  loss  of  the  teeth. 

All  of  these  drugs  are  in  some  degree  eliminated  from  the  system  by 
the  salivary  glands,  and  during  their  elimination  they  seem  to  perform  the 
functions  of  active  irritants.  A  moderate  degree  of  salivation  may  cause 
a  considerable  amount  of  soreness  and  tenderness  about  the  gums  and  the 
roots  of  the  teeth,  but  this  soon  subsides,  and  no  permanent  injury  has  been 
wrought.  But  if  this  condition  is  repeatedly  induced  or  maintained  for  a 
considerable  period,  pathologic  changes  are  established  in  the  pericemen- 
tum, which  permanently  injure  the  organs  of  mastication  and  hasten  their 
destruction. 

Symptoms  and  Diagnosis. — Pericementitis  due  to  the  toxic  effect  of 
mercury  upon  the  general  system  usually  involves  all  of  the  teeth.  The 
condition  generally  begins  with  an  increased  flow  of  saliva  and  a  metallic 
taste  in  the  mouth.  Later  pericemental  irritation  is  developed,  followed 
by  thickening  of  the  membrane  and  extrusion  of  the  teeth,  which  be- 
come loose  and  painful.  Pus  is  formed  in  the  alveoli  and  discharged  at 
the  margins  of  the  gums.  The  gums  become  inflamed,  swollen,  and  tur- 
gid, and  bleed  upon  the  least  provocation.  The  breath  is  offensive,  and  the 
saliva,  which  is  mixed  with  pus  and  blood,  has  the  odor  of  decomposing 
animal  matter.  The  tongue  is  swollen  and  often  fills  the  mouth,  pressing 
upon  the  teeth,  which  leave  their  imprint  upon  its  edges.  The  secre- 
tion of  the  saliva  is  so  great  that  it  constantly  drips  from  the  mouth,  and 
in  the  severer  cases  the  amount  may  reach  several  pints  in  twenty-four 
hours.  The  salivary  glands,  as  a  result  of  their  excessive  secretion  of 
saliva,  frequently  become  swollen  and  painful.  Diarrhoea  is  often  a  promi- 
nent symptom. 

The  excessive  flow  of  saliva  distinguishes  this  form  of  ptyalism  from 

^  Injuries  and  Surgical  Diseases  of  the  Face,  Mouth,  and  Jaws,  p.  272. 


DISEASES    OF   THE    PERICEMENTUM.  473 

all  others,  and  although  it  were  impossible  to  obtain  a  direct  history  of  the 
administration  of  mercury,  this  particular  symptom  alone  would  strongly 
indicate  the  nature  of  the  affection. 

Prognosis. — The  prognosis  in  the  milder  form  of  the  affection  is  favor- 
able to  a  complete  recovery  of  the  tissues  to  a  normal  condition.  In  the 
severer  cases  the  teeth  are  not  only  endangered,  but  the  gums,  alveolar 
processes,  and  even  the  jaws  may  be  seriously  affected.  Gangrene  and 
sloughing  of  the  gums,  necrosis  of  the  alveolar  processes,  and  loss  of  the 
teeth  are  common  sequelae,  and,  as  already  indicated,  necrosis  of  the  body 
of  the  jaw  may  sometimes  be  added  to  the  category  of  evil  results  which 
have  followed  the  administration  of  even  small  doses  of  mercury.  Fibrous 
or  cicatricial  anchylosis  of  the  jaws  sometimes  follows  as  a  result  of  slough- 
ing of  the  gams  and  mucous  membrane  of  the  cheeks,  which  upon  healing 
bind  the  jaws  together  with  cicatricial  bands. 

Treatment. — The  treatment  of  this  form  of  pericementitis  must  be 
directed  to  the  systemic  condition  ;  the  first  step  being  to  cut  off  the  ad- 
ministration of  the  drug  and  hasten  its  elimination  from  the  system.  This 
may  be  accomplished  by  means  of  potassium  iodide,  purgative  mineral 
waters,  diuretics,  and  diaphoretics.  The  diet  should  be  generous  and  com- 
posed of  the  most  nutritious  food.  The  local  conditions  may  be  treated 
with  solutions  of  potassium  chlorate,  silver  nitrate  or  hydrochloric  acid, 
and  astringent  deodorant  mouth- washes.  Especial  care  should  be  given  to 
the  cleanliness  of  the  mouth.  Hydrogen  dioxide  will  be  found  a  most 
efficient  remedy  for  this  purpose  sprayed  into  the  mouth  and  between  the 
teeth. 


CHAPTBE    XXIX. 

DENTO- ALVEOLAE   ABSCESS. 

Definition. — Abscess,  from  the  Latin  abscedere,to  depart. 

An  abscess  is  an  accumulation  of  pus  in  the  tissues  of  the  body,  re- 
sulting from  a  localized  inflammation,  and  which  is  surrounded  by  a  wall 
of  lymph  (formerly  termed  the  pyogenic  membrane,  from  the  erroneous 
notion  that  it  secreted  pus).  An  abscess  may  also  be  termed  a  hollow 
ulcer. 

A  dento-alveolar  abscess  is  an  accumulation  of  pus  within  a  dental  alveo- 
lus, or  associated  therewith,  and  dependent  upon  a  septic  inflammation 
of  the  tissues  of  the  apical  space  or  the  pericementum,  the  former  re- 
sulting from  a  gangrenous  pulp,  the  latter  from  various  forms  of  irritation 
or  injuries  resulting  in  suppurative  inflammation. 

Causes. — Suppurative  inflammation  always  precedes  the  formation  of 
an  abscess,  and  the  presence  of  pyogenic  bacteria  is  necessary  to  establish 
a  suppurative  inflammation  ;  hence  it  may  be  stated  that  an  abscess  is  the 
result  of  the  infection  of  the  tissues  with  the  i^yogenic  micro-organisms 
which  produce  the  destruction  of  the  exuded  leucocytes  and  the  cellular 
elements  of  the  tissues  at  the  point  of  infection,  and  the  liquefaction  of 
the  intercellular  substance,  thus  forming  pus. 

It  is  possible,  however,  to  produce  pus  without  the  agency  of  micro- 
organisms, as,  for  instance,  by  the  injection  of  croton  oil  and  other  violent 
irritants  beneath  the  skin ;  but  the  pus  so  formed  is  aseptic,  and  if 
other  animals  are  inoculated  with  it,  it  does  not  produce  inflammatory 
symptoms,  while  a  septic  pus  produced  by  the  action  of  the  pyogenic  or- 
ganism will  invariably  cause  suppurative  inflammation  if  a  sufficient 
quantity  is  introduced  into  the  tissues. 

Exciting  Causes. — The  exciting  causes  of  dento-alveolar  abscess  are 
found  in  septic  conditions  resulting  from  the  death  of  the  pulp  and  fjom 
certain  inflammatory  aifections  of  the  pericementum  considered  in  the 
preceding  chapter. 

The  most  common  exciting  causes  of  dento-alveolar  abscess  are  the 
organisms  of  suppuration  and  of  decomposition, — viz.,  the  pyogenic  and 
saprophytic  bacteria.  These  organisms  are  constantly  found  in  the  mouths 
of  even  the  most  cleanly  persons,  and  are  an  ever-present  menace  to  all 
operations  upon  soft  tissues  which  break  the  continuity  of  their  surface, 
and  the  pulps  of  teeth  which  have  been  exposed  by  caries  or  by  surgical 
traumatism. 

The  ptomaines  or  waste  products  of  these  organisms,  and  the  mephitic 
gases  formed  (hydrogen  sulphide,  H^S)  as  the  result  of  the  decomposition 
of  the  tissues  of  the  pulp,  passing  through  the  apical  foramen  and  coming 
in  contact  with  the  tissues  of  the  apical  space,  cause  irritation  and  a 
lowered  vitality  of  the  tissues  as  a  result  of  their  poisonous  effect.  The 
474 


DENTO -ALVEOLAR   ABSCESS.  475 

inflammation  whicli  follows,  however,  is  not  always  of  the  same  character 
or  intensity,  the  difference  in  these  respects  being  controlled,  seemingly, 
by  certain  x^redisposing  causes, — viz.,  the  vii'ulence  of  the  organisms,  the 
local  resistance  or  stamina  of  the  tissues,  and  the  general  condition  of  the 
individual. 

Predisposing  Causes. — The  character  of  a  septic  inflammation  de- 
pends in  great  measure  upon  the  virulence  of  the  organisms  which  have 
been  introduced  into  the  system.  This  is  a  well-established  law  in  both 
pathology  and  animal  toxin  therapy,  and  has  been  abundantly  demon- 
strated by  experiments  upon  animals  and  ujjon  man,  as,  for  instance,  in 
the  treatment  of  anthrax  with  the  attenuated  virus,  and  of  malignant 
inoperable  sarcomas  with  the  toxins  of  the  bacillus  prodigiosus  and  with  the 
streptococcus  erysipelatus. 

The  effect  of  an  infection  with  the  pyogenic  cocci  will  always  vary 
with  the  number  of  the  organisms  which  have  entered  the  tissues.  Watson 
Cheyne  found  in  his  experiments  with  the  proteus  vulgaris  of  Hauser — a 
bacterium  commonly  associated  with  putrefaction — that  a  dose  of  one- 
tenth  cubic  centimetre  of  an  undiluted  culture  contained  about  two  hun- 
dred and  fifty  million  bacteria,  and  when  injected  into  the  muscular  tissue 
of  a  rabbit  quickly  proved  fatal ;  while  a  dose  of  one-fortieth  cubic  centi- 
metre, containing  about  fifty-six  million,  caused  very  extensive  abscesses, 
and  resulted  in  death  of  the  animal  in  from  six  to  eight  weeks.  Doses 
which  contained  less  than  eighteen  million  very  rarely  produced  any  eflect. 
These  experiments  demonstrated  the  fact  that  the  system  when  in  a  healthy 
condition  has  wonderful  resistive  power  against  the  organisms  of  disease. 

He  further  demonstrated  with  cultures  of  the  staphylococcus  pyogenes 
aureus  that  it  was  necessary  to  inject  a  dose  sufficient  to  include  at  least 
one  billion  cocci  into  the  muscle  of  a  rabbit  to  produce  a  speedy  fatal 
result,  while  a  dose  containing  two  hundred  and  fifty  million  caused  the 
formation  only  of  a  small  circumscribed  abscess. 

The  staphylococcus  pyogenes  albus  produced  the  same  results,  but  required 
somewhat  larger  doses. 

Another  fact  of  great  interest  was  discovered  by  this  investigator, — ^viz., 
that  concentration  of  the  septic  material  in  a  certain  locality  was  necessary 
to  produce  the  most  marked  results.  Dividing  the  dose  and  injecting  it  at 
different  times,  or  in  different  localities  at  the  same  time,  did  not  produce 
the  same  results  as  when  it  was  all  injected  into  a  single  locality. 

The  tone,  resistance,  or  stamina  of  the  tissues  play  an  important  part 
in  the  predisposition  to  infection.  Tissues  whose  vitality  or  resistive 
powers  have  been  lowered  by  traumatism,  either  accidental  or  surgical,  or 
by  disease,  succumb  more  readily  to  a  septic  infection  than  do  tissues  in  a 
normal  condition.  Healthy  protoplasm  is  possessed  of  great  resistive 
power  to  the  action  of  disease-producing  bacteria,  and  this  is  the  salvation 
of  the  human  race.  But  for  this  every  member  of  the  human  family 
would  become  diseased,  and  the  race  soon  swept  from  the  face  of  the  earth. 

The  general  condition  or  tone  of  the  individual  is  an  important  factor 
in  the  predisposition  to  infection.  Persons  who  are  debilitated  from  illness, 
overwork,  anxiety,  debauchery,  and  other  causes  are  far  more  susceptible 


476  OPEEATIVE    DENTISTRY. 

to  the  invasion  of  patliogenic  organisms  than  are  those  in  robust  health. 
The  same  is  true  of  individuals  who  have  inherited  syphilis  and  that  con- 
dition generally  known  as  struma.  In  these  cases  the  evidence  of  a  lack 
of  vital  resistive  power  is  often  strongly  marked,  and  when  children  pos- 
sessing these  diatheses  are  attacked  by  disease,  they  more  readily  succumb 
than  do  those  children  born  of  healthy  parents.  In  this  class  of  individ- 
uals all  inflammatory  conditions  of  the  tissues  of  the  mouth  and  the  teeth 
run  a  violent  course,  and  suppurative  conditions  which  involve  the  periqe- 
mentum,  the  periosteum,  the  alveolar  processes,  or  the  body  of  the  jaw  are 
prone  to  result  in  phlegmonous  conditions  of  the  soft  tissues,  involvement 
of  the  lymphatic  glands,  and  not  infrequently  in  septic  intoxication. 

Certain  acquired  cachexia}  like  syphilis  and  tuberculosis  also  predispose 
the  individual  to  a  more  virulent  manifestation  of  a  septic  inflammation 
than  in  persons  of  good  constitution,  for  the  reason  that  these  diseases 
markedly  lower  the  power  of  resistance  of  the  tissues  and  decrease  the 
phagocytic  power  of  the  leucocytes.  These  predispositions  are  most  pro- 
nounced in  early  life,  and,  as  a  rule,  grow  less  and  less  prominent  with 
the  advancement  of  age  ;  but  sometimes  they  persist  throughout  the  whole 
lifetime  of  the  subject. 

Varieties. — Dento-alveolar  abscess  presents  in  two  forms, — viz.,  acute 
and  chronic.  In  the  acute  form  the  symptoms  are  often  very  severe  and 
sometimes  alarming,  resulting  in  extensive  necrosis  of  bone,  gangrene  and 
sloughing  of  soft  tissues,  acute  septicaemia,  pyeemia,  and  death.  In  the 
clironic  form  of  the  disease  the  symptoms  are  of  a  much  milder  type,  but 
necrosis  of  bone,  septicaemia,  and  pyaemia  are  not  unheard-of  conditions 
in  connection  with  chronic  alveolar  abscess. 

Dento-alveolar  abscess  is  sometimes  described  as  open  or  patulous,  and 

blind.    An  open  or  patulous  abscess  is  one  which  has  a  fistula  through  the 

gum  or  other  location,  from  which  the  accumulated  pus  discharges.     A 

blind  abscess  is  one  which  has  no  opening,  except  the  pulp- 

^^'  canal,  through  which  the  pus  could  escape.     Blind  abscesses 

are  usually  of  the  chronic  or  subacute  variety. 

Pathology. — When  the  pyogenic  bacteria  gain  an  entrance 
to  the  tissues  of  a  living  body  they  accumulate  very  rapidly, 
forming  a  minute  colony  which  by  their  concentrated  action,  or 
that  of  their  chemic  product,  causes  coagulation  of  the  serum 
and  of  the  contiguous  tissue,  —  "coagulation  necrosis," — thus 
forming  a  nidus  or  central  point  for  the  development  of  the 
process  of  suppuration.  Around  this  central  point,  composed 
shredd  sac  ^^  uccrotic  tissuc  and  containing  a  colony  of  micro-organisms, 
oriymph-waH  the  leucocytcs  accumulate  in  great  numbers,  completely  en- 
of  tooth  ab-     closing  it  bv  forming  a  wall  of  lymph,  as  shown  in  Fig.  574 

scess    as    met  &  j  &  j      x     ■>  to 

withindento-     (the  pyogcuic  membrane  of  the  older  writers). 

alveolar    ab-  According  to  the  theory  of  Metchnikoff,  certain  cells,  known 

scess.  o  ^  It 

as  phagocytes,  play  an  important  part  in  limiting  the  action  of 
the,  bacteria.  The  phagocytes  are  of  two  varieties,  fixed  and  free.  The 
fixed  phagocytes  are  the  endothelial  cells  and  the  fixed  connective-tissue 
cells,  while  the/ree  phagocytes  are  the  wandering  cells  or  leucocytes.    It  is 


DENTO  ALVEOLAR    ABSCESS.  477 

claimed  that  the  phagocytes  attack  the  micro-organisms  which  are  found 
in  the  tissues  and  destroy  them.  These  organisms  under  certain  circum- 
stances are  found  within  the  body  of  phagocytes,  and  for  this  reason  it 
has  been  believed  that  the  phagocytes  devour  bacteria.  This  theory  has 
also  been  advanced  by  Metchnikoff  and  others  in  explanation  of  immunity 
to  disease.  Immunity  or  susceptibility,  it  is  claimed,  depends  upon  the 
ability  or  inability,  respectively,  of  the  phagocytes  to  destroy  micro-organ- 
isms. This  theory  may  be  entirely  correct,  but  as  yet  it  is  not  universally 
adopted.  One  of  the  strongest  arguments  against  it  is  the  fact  that  infec- 
tious diseases  can  be  i)roduced  by  the  peculiar  poisons  or  waste  products 
elaborated  by  the  bacteria  and  without  the  presence  of  the  organisms  which 
elaborated  the  peculiar  poison. 

Formation  of  Pus. — Through  the  agency  of  the  peptonizing  power 
of  the  micro-organisms  lodged  at  the  point  of  infection  the  central  mass 
of  dead  tissue,  formed  by  the  process  of  coagulation,  and  the  contiguous 
intercellular  substance  are  liquefied.  This  process  liberates  the  exuded 
leucocytes  which  were  entangled  in  the  meshes  of  the  intercellular  sub- 
stance, and  they  become  mixed  with  the  liquefied  material  and  break  down 
into  a  granular  detritus,  which,  with  the  dead  leucocytes,  forms  pus.  This 
process  continues  with  greater  or  less  rapidity,  according  to  the  char- 
acter of  the  inflammation  and  the  diathesis  of  the  individual,  the  quantity 
of  the  pus  steadily  increasing  in  amount ;  tension  of  the  surrounding 
tissues  results,  and  both  the  bony  and  soft  structures  are  destroyed  by 
molecular  necrosis  until  the  surface  is  reached,  following  that  course  which 
offers  the  least  resistance.  This  is  termed  pointing,  and  through  this  open- 
ing the  fluid  contents  of  the  abscess  are  discharged.  During  the  process 
of  the  formation  of  the  abscess  active  cell  proliferation  in  the  fixed  tissue- 
cells  is  going  on  in  the  outer  portion  of  the  wall  of  leucocytes  ;  while  upon 
the  inside  of  the  abscess-cavity  a  new  tissue  is  formed,  known  as  granu- 
lation-tissue, which  by  its  growth  repairs  the  damage  caused  by  the  death 
and  liquefaction  of  the  tissues  involved  in  the  abscess.  This  tissue  is  com- 
posed chiefly  of  small,  round  cells  with  scanty  intercellular  substance,  but 
very  rich  in  capillary  blood-vessels,  each  granulation-point  being  occu- 
pied by  minute  capillary  loops. 

Location. — According  to  the  common  acceptation  of  the  term,  an 
alveolar  abscess  is  an  accumulation  of  pus  located  in  the  apical  space,  the 
result  of  septic  inflammation  induced  by  a  decomposing  gangrenous  pulp  ; 
and  for  various  reasons  it  would  seem  best  to  restrict  the  use  of  the  tei-m 
to  this  particular  form  of  dento-alveolar  abscess.  It  is  true,  however,  that 
abscesses  are  formed  within  the  dental  alveolus  which  have  no  connection 
with  a  gangrenous  pulp  ;  in  fact,  they  are  frequently  found  in  the  alveoli 
of  vital  teeth,  as,  for  instance,  in  pyorrhoea  alveolaris  and  inflammatory 
conditions  arising  from  various  forms  of  irritation  and  traumatisms  of  the 
pericementum. 

In  the  formation  of  a  dento-alveolar  abscess  the  pus  is  at  first  confined 
to  the  apical  space,  where  it  is  surrounded  by  bony  walls.  As  the  pus 
accumulates  pressure  is  brought  to  bear  upon  the  surrounding  walls ;  this 
pressure,  together  with  the  dissolving  or  peptonizing  action  of  the  bacteria, 


478  OPERATIVE    DENTISTRY. 

causes  a  rapid  cell-necrosis  and  disintegration  of  the  surrounding  cancel- 
lated bone,  and  a  gradually  increasing  cavity  is  formed  at  the  apex  of  the 
root.  The  tendency  of  the  accumulated  pus,  assisted  by  the  pressure 
within  the  cavity,  is  to  seek  an  exit  in  a  direction  that  offers  the  least 
resistance. 

The  external  or  buccal  wall  of  the  alveolar  process  is  the  thinnest,  and 
offers  the  least  resistance  to  the  progress  of  the  accumulated  pus  ;  for  this 
reason  the  abscess  usually  points  upon  the  buccal  aspect  of  the  alveolar 
process,  opposite  the  apex  of  the  root. 

Dento-alveolar  abscesses  point  in  three  distinct  ways  after  penetrating 
the  bony  walls :  first^  directly  through  the  soft  tissues ;  secondly^  by  sepa- 
rating the  periosteum  from  the  bone  and  forming  a  secondary  pus-cavity  ; 
tJiirdly,  by  following  the  pericementum  along  the  side  of  the  root  and 
discharging  at  the  margin  of  the  gum. 

Dento-alveolar  abscesses  which  point  directly  through  the  gum-tissues 
are  the  most  common,  and  rarely  present  any  complications.  The  second 
form  is  often  complicated  with  necrosis  of  portions  of  bone,  and  by  pene- 
trating the  external  tissues  of  the  face  or  burrowing  downward  into  the 
tissues  of  the  neck.  For  these  reasons  such  an  abscess  should  receive 
prompt  attention,  in  order  that  the  destructive  process  may  be  confined  to 
the  narrowest  limits  and  disfiguration  and  other  more  serious  consequences 
be  prevented. 

The  relations  of  the  roots  of  the  incisor  and  cuspid  teeth  to  the  floor 
of  the  nose  are  such,  in  many  instances,  that  alveolar  abscesses  may  point 
through  the  floor  of  the  nasal  fossa  and  produce  a  purulent  discharge  that 
might  readily  be  mistaken  for  chronic  nasal  catarrh.  The  relations  of  the 
roots  of  the  bicuspid  and  molar  teeth  to  the  floor  of  the  antrum  are  such 
as  to  make  it  even  less  difficult  for  an  abscess  connected  with  one  of  these 
teeth  to  penetrate  the  floor  of  the  sinus. 

Abscesses  in  connection  with  the  teeth  of  the  lower  jaw  may  penetrate 
the  alveolar  process,  but  fail  to  penetrate  the  gum,  and  by  force  of  gravi- 
tation and  the  pressure  of  the  accumulating  pus  make  paths  for  themselves 
between  the  periosteum  and  the  soft  tissues,  or  between  the  periosteum 
and  the  bone,  and  finally  discharge  upon  the  face  beneath  the  chin  or  the 
jaw.  Or  they  may  burrow  through  the  body  of  the  jaw.  Abscesses  in 
relation  with  the  third  lower  molars  often  penetrate  the  external  tissues  at 
the  angle  of  the  jaw,  or  they  may  occasionally  burrow  downward  into  the 
neck,  forming  large  pus-cavities  in  the  submaxillary  triangle.  The  writer 
has  operated  upon  several  cases  of  this  character,  from  which  j)us  varying 
in  amount  from  four  ounces  to  a  pint  had  been  removed.  In  some  of  these 
cases  the  tissues  were  so  infiltrated  with  the  pyogenic  cocci  that  for  weeks 
after  the  original  abscess  had  healed,  and  the  offending  tooth  had  been  re- 
moved, crop  after  crop  of  phlegmonous  abscesses  appeared  in  the  neigh- 
borhood, located  in  the  cellular  tissue  immediately  beneath  the  skin. 

Another  form  of  dento-alveolar  abscess  is  one  which  has  no  external  sinus 
for  the  discharge  of  the  pus.  These  cases  have  been  for  this  reason  designated 
as  Nind  abscesses.  The  term  is,  however,  hardly  a  correct  one,  for  the 
pus  discharges  through  the  pulp-canal,  which  becomes  its  sinus,  and  it  is 


DENTO-ALVEOLAR    ABSCESS.  479 

therefore  not  a  blind  abscess.  These  abscesses  are  usually  small,  and,  as  a 
rule,  have  not  been  very  painful ;  in  fact,  all  of  the  acute  symptoms  have 
been  greatly  modified  by  reason  of  the  ready  exit  of  the  pus  from  the 
beginning  of  the  suppurative  process. 

Abscesses  which  discharge  along  the  side  of  the  root  and  find  exit  at 
the  margin  of  the  gum  are  sometimes  confounded  with  the  so-called  blind 
abscess,  but  in  these  eases  a  careful  examination  will  reveal  the  fact  that 
there  is  no  discharge  through  the  pulp-canal.  Many  times  this  form  of 
abscess  is  associated  with  pulpless  teeth  whose  roots  have  been  filled,  but 
in  which  there  is  sufficient  septic  irritation  to  keep  up  a  chronic  discharge 
of  pus  through  the  sinus  which  has  been  formed  by  the  side  of  the  root. 

CHKONIC   DENTO-ALTEOLAE,   ABSCESS. 

A  chronic  dento-alveolar  abscess  is  one  which  has  passed  through  the 
acute  stage,  but  in  which  the  after-symptoms  have  been  greatly  modified. 
Acute  dento-alveolar  abscesses  rarely  heal  spontaneously  ;  there  is,  how- 
ever, a  partial  filling  up  of  the  pus-cavity  by  the  growth  of  the  granu- 
lation-tissue which  lines  it.  But  there  is  usually  a  sufficient  amount  of 
decomposition  of  tissue  and  the  growth  of  micro-organisms  within  the 
abscess  cavity  and  the  pulp-canal  to  keep  up  a  continuance  of  the  sup- 
purative process  and  a  discharge  of  pus. 

Occasionally  a  dento-alveolar  abscess  may  X3resent  chronic  symptoms 
from  the  very  beginning  of  the  suppurative  process,  as,  for  instance,  in 
hlind  abscess.  In  many  of  these  cases  no  marked  inflammatory  symptoms 
have  developed  at  any  time,  and  yet  there  is  often  a  prolonged  and  obsti- 
nate irritation  at  the  apical  space  and  a  persistent  accumulation  of  pus, 
which  finds  an  exit  through  the  pulp-canal. 

Abscesses  which  have  pointed  through  the  external  tissues  of  the  face 
are  nearly  always  of  a  chronic  type,  particularly  those  which  have  had 
their  origin  in  ancient  traumatisms,  perforation  of  the  cementum,  broken 
instruments  within  the  root- canal,  or  from  an  impacted  position  of  a  tooth. 

Symptoms  and  Diagnosis. — The  symptoms  of  acute  dento-alveolar 
abscess  in  its  early  stage  are  the  same  as  in  acute  septic  apical  pericemen- 
titis. If  inflammation  of  the  pericementum  of  a  puli^less  tooth  with  the 
pulp-chamber  open  has  continued  for  from  twenty-four  to  thirty-six  hours, 
pus  has  doubtless  been  formed.  With  the  formation  of  pus  the  symptoms 
become  more  aggravated.  The  gums  in  the  region  of  the  affected  tooth 
assume  an  inflamed  condition  ;  the  pain  is  of  a  deep  throbbing  character, 
which  at  times  is  almost  intolerable.  With  the  formation  of  pus  there  is 
often  a  rigor,  or  chilly  sensations  are  exxDerienced,  lasting  for  an  hour  or 
two.  This  is  followed  by  an  elevation  of  temperature ;  the  more  severe 
the  rigor  the  higher  the  fever  will  run.  The  temperature  may  vary  from 
101°  to  103°  or  105°  F. ,  according  to  the  virulence  of  the  infection  and  the 
susceptibility  of  the  individual  to  septic  irritation. 

As  soon  as  the  pus  penetrates  the  bony  walls  of  the  abscess  and  escapes 
into  the  soft  tissues  the  severity  of  the  pain  is  abated,  but  the  tissues 
begin  immediately  to  swell,  and  the  swelling  may  be  so  great  when  the 
affected  tooth  is  located  in  the  upper  jaw,  as  to  close  the  eye,  or  when 


480  OPEEATIVE    DENTISTRY. 

located  in  the  lower  jaw  to  cause  great  swelling  of  tlie  neck,  especially  in  the 
submaxillary,  triangle.  The  cervical  lymphatic  glands  may  also  become 
swollen  and  tender,  and  sometimes  suppuration  takes  place  in  them.  The 
pus  occasionally  collects  in  great  quantity,  and  under  such  circumstances  it 
is  not  uncommon  for  such  abscesses,  when  located  in  the  upper  jaw  in  con- 
nection with  the  incisors  and  cuspids,  to  rupture  into  the  nasal  cavity,  and 
for  the  bicuspids  and  molars  to  discharge  into  the  antrum  of  Highmore, 
or  through  the  external  tissues  of  the  face,  while  those  in  the  lower  jaw 
may  rupture  through  the  external  tissues  of  the  jaw  or  burrow  down- 
ward, following  the  fascia  of  the  neck,  and  rupture  at  any  point  above  the 
clavicle.  Cases  are  on  record  where  abscesses  in  connection  with  the  lower 
third  molars  have  burrowed  downward  and  discharged  into  the  larynx  and 
at  points  upon  the  chest  as  low  down  as  the  mammary  glands.  Infection 
and  swelling  of  the  lymphatic  glands  of  the  neck  is  a  frequent  accompani- 
ment of  alveolar  abscesses,  while  metastatic  abscesses  have  been  formed  in 
various  parts  of  the  body  as  a  result  of  the  invasion  of  the  blood-current 
by  the  organisms  of  the  abscess. 

Dento-alveolar  abscesses  which  discharge  into  the  nasal  fossa  have  been 
mistaken  for  cases  of  chronic  nasal  catarrh,  while  such  abscesses  discharging 
into  the  maxillary  sinus  are  productive  of  the  most  troublesome  cases  of 
empyema  of  this  sinus. 

The  diagnostic  signs  of  acute  dento-alveolar  abscess  are  discoloration  of 
the  tooth,  no  response  to  the  thermal  test,  showing  that  the  pulp  is  dead, 
tenderness  to  percussion,  elongation  of  the  tooth,  looseness  in  its  alve- 
olus, tenderness  to  palpation  over  the  apex  of  the  root,  swelling  and 
inflammation  of  the  gum,  and  fluctuation  at  that  location  where  the 
abscess  is  about  to  point.  The  character  of  the  pain  is  more  intense 
during  the  formation  of  the  pus  than  at  any  other  time,  and  is  relieved 
as  soon  as  the  swelling  of  the  external  tissues  begins. 

In  the  differential  diagnosis  it  must  be  remembered  that  a  sequestrum 
of  necrosed  bone  or  an  impacted  tooth  would  produce  symptoms  so  nearly 
like  those  of  dento-alveolar  abscess  as  to  be  readily  mistaken  for  that  condi- 
tion. In  fact,  sometimes  the  only  way  that  a  differential  diagnosis  can  be 
made  out  is  by  tracing  the  sinus  to  the  sequestrum  or  to  the  impacted  tooth. 
Prognosis. — The  prognosis  of  simple  uncomplicated  dento-alveolar 
abscess  is  generally  good  if  proper  antiseptic  methods  of  treatment  are 
instituted.  Occasionally,  however,  no  method  or  amount  of  treatment 
will  avail  to  save  some  of  these  teeth.  In  certain  individuals  the  death 
of  the  pulp  means  the  speedy  loss  of  the  tooth  from  chronic  septic  peri- 
cementitis and  resorption  of  its  alveolus.  Fortunately  these  cases  are  not 
very  common,  but  when  they  do  present  themselves  they  cause  an  untold 
amount  of  anxiety  during  the  effort  to  preserve  them,  and  deep  chagrin 
when  these  efforts  prove  futile  and  the  tooth  has  to  be  extracted. 

When  the  alveolar  abscess  is  complicated  with  necrosis  of  the  alveolar 
process  surrounding  the  tooth  it  is  commonly  lost  with  the  necrosed  bone  ; 
but  when  the  external  plate  alone  or  the  mesial  or  distal  septum  only  are 
lost,  the  tooth  may  in  many  instances  be  retained  and  restored  to  health 
and  usefulness. 


DENTO-ALVEOLAR   ABSCESS.  481 

When  it  is  complicated  with  perforation  of  the  floor  of  tlie  nasal  cavity 
or  of  the  maxillary  sinus  a  somewhat  serious  problem  is  presented.  It 
would  at  first  thought  seem  that  the  only  treatment  that  would  be  required 
to  cure  such  cases  was  to  properly  sterilize  the  pulp-canals  and  to  fill 
them.  Such  treatment  does  not,  however,  always  succeed,  for  the  reason 
that  there  is  very  great  difficulty  experienced  in  properly  sterilizing 
them,  on  account  of  the  constant  draining  of  the  fluids  of  the  nasal 
cavity  and  of  the  antrum  into  the  canals  ;  in  fact,  in  some  of  these  cases  it 
is  impossible  to  ever  get  them  in  such  a  condition  of  dryness  as  to  warrant 
the  introduction  of  a  root-filling.  Again,  it  is  not  at  all  uncommon  to  find 
the  apices  of  the  roots  of  these  teeth  more  or  less  eroded  ;  and  when  the 
abscess  has  become  chronic,  if  they  are  not  eroded  they  are  covered  with 
concretions  of  calcific  matter,  which  makes  it  impossible  for  the  roots 
of  these  teeth  to  ever  again  assume  a  healthy  condition.  The  prognosis 
is,  therefore,  unfavorable,  and  the  sooner  such  teeth  are  removed  the 
better.  Their  extraction  often  becomes  imperative  as  a  means  of  correct- 
ing the  discharges  from  the  nose  and  from  the  maxillary  sinuses. 

When  the  alveolar  abscess  is  complicated  with  a  sinus  ivhich  discharges 
upon  the  face  it  becomes  a  matter  of  considerable  interest  to  the  patient 
as  to  whether  the  offending  tooth  can  be  saved  and  the  disfiguration  of  the 
face  corrected  if  the  tooth  be  permitted  to  remain.  Such  cases  do  not  ordi- 
narily present  any  serious  difficulties  in  their  treatment.  One  such  case 
associated  with  a  cuspid  tooth,  which  was  referred  to  the  writer  by  a 
medical  friend,  discharged  by  the  side  of  the  nose  just  below  the  inner 
canthus  of  the  right  eye,  and  resisted  all  efforts  to  puncture  the  apical 
foramen  or  to  force  antiseptic  remedies  through  it ;  and  as  no  improve- 
ment could  be  seen  in  the  case  after  repeated  treatments  extending  over  a 
period  of  more  than  two  weeks,  it  was  thought  advisable  to  remove  the 
offending  tooth,  when,  upon  extracting  it,  a  steel  broach  was  found  in  the 
Tipper  fourth  of  the  canal,  and  projecting  beyond  the  foramen  a  full  half- 
inch.  Comment  is  unnecessary.  The  discharges  immediately  ceased,  and 
the  sinus  closed  in  less  than  a  week.  Later  the  discolored  tissue  was 
removed  by  an  elliptical  incision,  the  skin  loosened  from  the  fascia  and 
brought  together  with  very  fine  silk  sutures ;  the  wound  healed  by  first 
intention,  and  the  only  scar  left  was  a  delicate  straight  line  following  the 
natural  line  of  the  face. 

Dento-alveolar  abscess  is  sometimes  complicated  with  perforation  of  the 
cementum.  Perforations  of  the  pulp-canal  which  involve  the  pericemen- 
tum may  be  caused  in  several  ways  :  First,  by  caries  which  has  operated 
from  within  the  pulp-canal ;  secondly,  the  absorptive  action  of  the  osteo- 
clasts which,  as  a  reshlt  of  inflammation,  have  attacked  the  cement-tissue 
at  various  locations  upon  the  side  of  the  root  and  penetrated  to  the  pulp- 
canal  ;  and  thirdly,  by  the  injudicious  use  of  the  reamer  or  drill  in  en- 
larging the  pulp-canal  preparatory  to  filling,  or  forming  it  to  receive  a 
post  for  an  artificial  crown.  Such  cases  often  present  a  condition  of 
chronic  abscess  which  may  discharge  through  the  pulp-canal,  by  the  side 
of  the  root  at  the  margin  of  the  gum,  or  through  a  sinus  in  the  external 

tissues. 

31 


482  OPERATIVE    DENTISTRY. 

The  effect  of  such  a  perforation  is  to  establish  inflammation  of  the  peri- 
cementum and  sometimes  ulceration.  Perforations  which  are  the  result 
of  caries  or  absorption  are  irregular  in  outline,  and  the  edges  are  sharp 
and  rough.  These  conditions  present  an  added  source  of  irritation  which 
aggravates  the  inflammation  already  existent  and  stimulates  the  growth  of 
granulation-tissue.  This  new  tissue  enters  the  perforation  and  extends 
into  the  pulp-canal,  sometimes  completely  filling  it,  and  by  its  appearance 
and  hypersensitive  condition  has  misled  some  of  the  most  careful  observers 
into  the  belief  that  they  were  dealing  with  an  hypertrophied  pulp.  Under 
such  circumstances  the  application  of  arsenic  for  the  devitalization  of  what 
appeared  to  be  pulp-tissue  might  prove  exceedingly  disastrous.  The  ut- 
most care  should  be  exercised  in  reaching  a  diagnosis  in  these  cases. 

Perforations  which  are  the  result  of  a  surgical  traumatism  have  well- 
defined  edges,  as  a  rule,  and  if  immediately  treated  upon  scientific  prin- 
ciples will,  in  a  considerable  number  of  cases,  respond  kindly  to  such  treat- 
ment and  the  tooth  be  finally  conserved.  But  when  the  case  is  permitted 
to  run  along  without  proper  treatment  inflammation  of  the  pericementum 
follows,  and  the  conditions  which  have  just  been  described  may  develop, 
or  chronic  suppuration  may  be  established. 

In  those  cases  located  in  the  lower  jaw  where  the  abscesses  burrow 
through  the  body  of  the  jaw  and  open  upon  the  face  or  beneath  the  chin, 
or  extend  into  the  soft  tissues  of  the  submaxillary  triangle,  or  into  the 
deeper  tissues  of  the  neck,  immediate  extraction  should  be  recommended 
in  the  former  and  imperatively  demanded  in  the  latter.  In  the  former 
the  prognosis  is  considered  unfavorable,  for  the  reason  that  in  a  majority  of 
these  cases  the  apices  of  the  roots  will  be  found  more  or  less  eroded  as  a 
result  of  the  continued  inflammatory  conditions.  While  in  the  latter  the 
prognosis  is  considered  grave  by  reason  of  the  tendency  to  diffuse  cel- 
lulitis and  the  great  danger  that  acute  septicsemia  may  be  developed  by 
the  absorption  of  the  ptomaines,  or  that  pysemia  may  be  established  by  the 
invasion  of  the  pyogenic  organisms  or  the  entrance  of  pus  into  the  blood- 
current,  and  the  formation  of  metastatic  abscesses  in  remote  portions  of 
the  body. 

Treatment. — The  treatment  of  acute  dento- alveolar  abscess  often  de- 
mands vigorous  constitutional  treatment  to  abort  the  inflammatory  process, 
to  allay  the  suffering  incident  to  the  process  of  pus  formation  and  the  pene- 
tration of  the  bone  for  the  escape  of  the  pus,  and  to  control  the  high  tem- 
perature induced  by  the  severe  irritation  and  the  absorption  of  certain 
waste  products  of  the  micro-organisms. 

The  constitutional  measures  which  are  usually  employed  in  the  treat- 
ment of  alveolar  abscess  have  already  been  indicated  in  the  preceding 
chapter  on  Pericementitis. 

Local  Treatment. — The  treatment  of  acute  alveolar  abscess  in  its 
early  stages,  before  a  fistula  has  been  establisJwd,  comprehends, — 

1.  Efforts  to  abort  the  inflammation  by  the  employment  of  local  thera- 
peutic measures,  surgical  and  medicinal. 

2.  Limiting,  as  far  as  possible,  the  destruction  of  tissue  by  controlling 
the  suppurative  process. 


DENTO-ALVEOLAR   ABSCESS.  483 

3.  The  earliest  possible  evacuation  of  the  pns. 

4.  The  promotion  of  the  healing  process. 

Inasmuch  as  the  primary  seat  of  the  infection  which  establishes  the 
suppurative  process  in  the  apical  space  is  the  pulp-canal,  efibrts  should 
be  first  directed  to  gaining  an  entrance  to  this  seat  of  infection  and  thor- 
oughly removing  all  infectious  material.  It  is  an  axiom  in  general  medi- 
cine and  surgery  that  to  cure  a  disease  the  cause  must  first  be  removed. 
Having  remov^ed,  as  far  as  may  be,  by  mechanical  means,  the  gangrenous 
and  putrefying  pulp,  the  second  step  is  to  render  the  canals  aseptic  by 
saturating  or  irrigating  them  with  antiseptic  drugs,  and  thirdly,  by  local 
depletion,  induced  by  scarification  of  the  gums  in  the  neighborhood  of 
the  affected  tooth,  to  promote  bleeding  by  warm  water  held  in  the  mouth 
or  by  counter-irritation  of  the  gum  over  the  diseased  tooth,  as  indicated 
in  the  chapter  on  Pericementitis. 

If  these  measures  fail  to  abort  the  suppurative  process  by  reason  of  the 
escape  of  the  infectious  material  and  pyogenic  bacteria  into  the  apical 
space,  it  becomes  necessary,  in  order  to  limit  the  destruction  of  tissue,  to  reach 
this  focus  of  infection  by  surgical  means.  This  may  be  accomplished  in 
some  cases  through  the  apical  foramen  and  the  pus  evacuated  through  this 
channel ;  but  if  this  is  not  possible,  it  may  be  reached  by  trephining  the 
alveolar  plate,  or  by  the  extraction  of  the  tooth.  In  all  cases  where  the 
tooth  is  valuable  and  the  general  conditions  of  the  health  of  the  individual 
do  not  contraindicate,  every  effort  should  be  made  to  save  the  tooth.  But 
in  certain  conditions  of  the  system,  as  in  tuberculosis,  syphilis,  continued 
fevers,  anaemia,  general  debility,  nervous  prostration,  and  pregnancy,  the 
conservation  of  the  tooth  is  contraindicated,  as  in  all  but  the  latter  the 
vital  resistance  of  the  tissues  is  so  reduced  that  great  destruction  of  tissue 
is  likely  to  attend  all  suppurative  processes ;  while  in  the  latter,  if  the 
period  of  confinement  is  near,  it  is  imperative  that  all  suppurative  condi- 
tions be  abated  before  parturition  sets  in,  on  account  of  the  great  danger 
of  septic  infection  at  this  period,  and  the  establishment  of  puerperal 
fever  or  acute  septicaemia  from  the  presence  of  suppurative  foci  in  other 
portions  of  the  body,  and  the  infection  being  carried  in  the  blood- 
current. 

Blind  abscesses  should  be  permitted  to  drain  through  the  pulp -canal  for 
forty-eight  hours  or  longer,  in  fact,  until  pericemental  irritation  ceases, 
before  dressings  are  applied  to  the  root-canal. 

In  trephining  the  alveolar  plate  two  methods  have  been  suggested. 
Dr.  Black's  method  is  to  perforate  the  gum- tissue  by  the  escharotic  effect 
of  carbolic  acid,  full  strength,  carried  upon  a  serrated  plugger  of  suitable 
size,  and  api^lied  to  the  gum  at  the  point  selected  for  the  perforation,  and 
the  instrument  gently  rotated.  As  the  carbolic  acid  penetrates  the  tissue 
it  renders  it  anaesthetic,  while  the  rotation  of  the  serrated  instrument  cuts 
away  the  tissue  which  has  been  destroyed  by  the  escharotic  action  of  the 
drug.  In  this  way  the  gum  is  penetrated  without  causing  pain.  A  sharp, 
spear-pointed  drill  is  now  substituted  for  the  plugger,  and  the  bony  plate 
perforated  in  the  same  comparatively  painless  manner.  The  only  objection 
to  this  method  is  the  necessarily  slow  procedure,  as  the  instrument  cannot 


484 


OPERATIVE   DENTISTRY 


be  advanced  more  rapidly  than  the  penetration  of  the  carbolic  acid  renders 
the  tissues  anaesthetic. 

A  second  method  is  to  inject  subgiugivally  a  two  per  cent,  solution  of 
cocaine  hydrochlorate  over  the  root  of  the  affected  tooth  ;  make  a  triangu- 
lar flap  in  the  gum,  the  point  towards  the  crowns  of  the  teeth  ;  then,  with 
a  spear-pointed  drill  (Fig.  575)  or  a  small  trephine  (Fig.  576),  penetrate 


Fig.  577. 


Fig.  576. 


Spear-pointed  drills. 


IJl 
Trephines. 


the  alveolar  plate  at  the  apical  space  with  the  engine-drill  (A)  or  hand- 
drill  (B),  as  shown  in  Fig.  577,  as  suggested  by  Garretson.  By  this  method 
the  operation  may  be  done  entirely  without  pain,  except  from  the  injection 
of  the  cocaine  solution,  which  is  only  momentary.  On  reaching  the  apical 
space,  the  focus  of  infection  may  be  broken  up  and  the  abscess- cavity  irri- 
gated with  suitable  warm  antiseptic  solutions,  and  the  opening  in  the  gum 
and  the  alveolar  plate  kept  patulous  by  the  introduction  of  a  few  strands 
of  antiseptic  silk  or  cotton.  The  wound  and  the  abscess- cavity  should  be 
irrigated  two  or  three  times  per  day  until  the  inflammatory  symptoms  are 
abated,  when  the  case  may  be  treated  after  the  usual  manner,  and  as  soon 
as  the  conditions  are  favorable  the  pulj)- canals  should  be  filled. 

''Ubi  pus  ibi  evacuo,'"  when  there  is  pus  evacuate  it,  is  as  wise  a 
surgical  rule  for  to-day  in  the  treatment  of  acute  abscesses  as  when  it  was 
first  enunciated  centuries  ago.  The  expectant  treatment,  which  has  until 
recent  years  been  the  general  practice,  is  quite  rai)idly  giving  way  to  the 
more  rational  method  of  cutting  down  upon  the  seat  of  suppuration  and 
giving  immediate  exit  to  the  accumulated  pus,  as  by  this  method  the  dis- 
ease is  cut  short  and  much  suffering  saved  the  patient. 

A  safe  rule  to  follow  in  all  cases  of  acute  alveolar  abscesses  which  have 
not  yet  pointed  is  to  apijly  the  knife  and  give  immediate  exit  to  the  accu- 
mulated pus,  for  by  so  doing  great  relief  is  afforded  the  patient,  while 
the  destruction  of  tissue  is  thereby  limited,  and  the  dangers  from  general 
septic  infection  are  greatly  reduced. 

The  promotion  of  healing  is  accomplished  by  thorough  antisepsis  of  the 


DENTO-ALVEOLAR   ABSCESS.  485 

pulp-canals  and  the  abscess-cavity,  and  securing  rest  for  the  tooth  during 
its  restoration  to  health. 

In  the  treatment  of  abscessed  teeth  which  have  discharged  into  the 
nasal  fossa  or  the  antrum  of  Highmore,  extraction  is  the  only  satisfactory 
method  of  treatment,  while  in  those  which  have  penetrated  the  external 
tissues  of  the  face  it  is  also  generally  the  safest  practice,  especially  in  those 
cases  which  do  not  respond  to  the  ordinary  methods  of  treatment,  such  as 
sterilization  of  the  pulp-canals,  abscess- cavity,  and  fistulous  tract,  and  the 
employment  of  such  escharotics  as  creosote  and  carbolic  acid  pumped 
through  them,  or  drawn  through  them  by  the  cupping  device  recommended 
by  Drs.  T.  M.  Hunter*  and  Burchard-f  This  device  is  formed  of  the 
ordinary  rubber  polishing-cup  mounted  ux^on  a  mandrel,  and  used  by  first 
moistening  the  inside  of  the  cup  and  pressing  it  over  the  fistulous  opening 
>.  until  the  air  is  excluded,  when  the  vacuum  which  has  been  created  by 
allowing  the  cup  to  assume  its  natural  shape  will  emi)ty  the  pus-cavity, 
and  if  creosote,  carbolic  acid,  or  other  fluid  substance  has  been  placed  in 
the  pulp-canal,  it  will  be  drawn  through  the  fistulous  tract  and  appear  at 
its  exit. 

In  the  treatment  of  abscesses  arising  from  devitalized  or  impacted  teeth 
located  in  the  lower  jaw  which  have  not  pointed,  but  in  which  the  pus 
has  accumulated  in  considerable  quantities  and  burrowed  downward  into 
the  submaxillary  and  carotid  triangles,  the  immediate  extraction  of  such 
teeth  and  the  evacuation  of  the  pus  by  external  incision  is  imi^eratively 
demanded.  In  opening  such  abscesses  the  incision  should  be  made  at  the 
lowest  point  of  the  pus-cavity,  and,  on  account  of  the  danger  from  wounding 
the  important  blood-vessels  located  in  these  parts,  the  incision  with  the 
bistoury  should  only  be  carried  through  the  skin,  when,  with  a  pair  of 
hsemostatic  snap- forceps  with  the  blades  closed,  the  point  may  be  insinuated 
between  the  fibres  of  the  muscles  and  carried  into  the  abscess,  and  as  they 
are  withdrawn  the  blades  may  be  oj)ened  and  the  fibres  of  the  muscles 
still  farther  separated.  By  this  method  of  tunnelling  the  tissues  all  danger 
of  wounding  the  blood-vessels  is  entirely  obviated. 

After  the  evacuation  of  the  pus  the  cavity  is  thoroughly  irrigated,  a 
drainage-tube  inserted,  and  the  external  wound  dressed  with  several  layers 
of  absorbent  cotton  liberally  sprinkled  with  powdered  boric  acid  or  iodo- 
form, and  a  bandage  applied. 

Of  course  it  is  understood  that  so  formidable  an  operation  will  require 
a  general  anaesthetic  and  the  confinement  of  the  patient  to  the  bed  for 
several  days. 

Chronic  Alveolar  Abscess. — The  treatment  of  the  ordinary  chronic 
alveolar  abscesses  with  fistulous  openings  should  follow  the  same  line  of 
procedure  as  that  just  laid  down  for  the  treatment  of  acute  abscess  with 
fistulous  opening. 

Abscesses  which  are  associated  with  perforations  of  the  walls  of  the 
root  communicating  with  the  pulp-canal  are  in  a  very  large  majority  of 

*  Dental  Cosmos,  vol.  xxxiv.  p.  82. 
t  Burchard's  Dental  Pathology,  p.  379. 


486  OPERATIVE   DENTISTRY. 

instances  in  a  chronic  state  when  presented  for  treatment.  In  those  cases 
which  are  the  result  of  a  surgical  traumatism  of  recent  date,  occurring  at 
any  point  above  the  middle  of  the  root  (the  morsal  half),  the  chances  for 
successful  treatment  are  very  good  indeed,  provided  resorption  of  the  root 
in  the  immediate  neighborhood  has  not  begun. 

The  perforation  may  be  closed  in  the  following  manner :  after  having 
arrested  the  hemorrhage  with  tannin  and  glycerol  or  phenol  sodique,  and 
the  cavity  thoroughly  sterilized  and  maintained  in  that  condition  during 
the  balance  of  the  operation,  a  disk  of  No.  60  gold-foil,  or,  better,  a  disk 
of  tin  cut  from  a  sheet  of  No.  4  tin-foil  which  had  been  doubled  ujjon 
itself  four  times,  or  sixteen  thicknesses,  may  be  dipped  in  chlora-percha 
and  laid  over  the  opening  and  carefully  pressed  into  place,  the  canal  filled 
with  gutta-percha,  and  the  cavity  in  the  crown  sealed  with  zinc  oxyphos- 
phate. 

In  those  cases  which  are  the  result  of  pathologic  states  the  treatment 
becomes  much  more  difficult.  When  the  pulp- canal  is  filled  with  granula- 
tion-tissue, this  can  be  removed  by  first  applying  a  local  anaesthetic  like 
cocaine  or  eucaine,  which  in  many  instances  can  be  employed  cataphori- 
cally.  Or  an  ethereal  solution  of  chloretone — equal  weights  of  each — may 
be  applied  upon  a  pledget  of  cotton.  As  soon  as  it  is  thoroughly  anaes- 
thetized it  can  be  removed  with  a  small  sharp-pointed  lancet,  delicate 
enough  to  enter  the  pulp-canal  for  at  least  half  its  depth.  After  the  bleed- 
ing has  been  arrested,  the  cavity  may  be  packed  with  cotton  dipped  in 
powdered  boracic  acid  and  sealed  with  gum  sandarach.  These  dressings 
should  be  renewed  every  day  for  a  week,  when  the  canal  may  be  sterilized 
and  the  lower  half  filled  with  a  gutta-percha  point,  the  perforation  covered 
as  just  described,  and  the  balance  of  the  cavity  filled  with  gutta-percha. 
If  the  first  treatment  is  not  successful,  try  again  and  again,  if  the  impor- 
tance of  the  tooth  will  warrant  it.  If,  however,  after  repeated  trials  the 
tooth  remains  tender  and  irritable,  it  will  be  the  wiser  plan  to  extract  it. 
The  same  is  true  of  those  perforations  which  occur  at  that  portion  which 
may  be  termed  the  apical  half  of  the  root.  In  these  cases  gutta-percha  is 
the  only  reliable  material  which  can  be  used  for  closing  perfoi^ations  in 
this  part  of  the  canal.  The  uncertainty  attending  the  adjustment  of  the 
metal  disk  to  the  perforation  in  such  a  location,  or  even  adapting  a  gutta- 
percha pellet  over  it  that  will  not  produce  pressure,  is  so  great  that  they 
rarely  prove  successful.  A  perforation  such  as  would  be  made  by  a  drill 
passing  through  a  curved  root  is  usually  so  clean  cut  that  it  can  be  readily 
closed  by  a  pellet  of  tin-foil  or  gutta-percha,  but  the  septic  material  still 
remains  in  the  curved  extremity  of  the  root,  where  it  will  become  a  men- 
acing source  of  infection  and  irritation.  It  is  better,  therefore,  under  such 
circumstances,  to  extract  the  tooth  at  once  rather  than  to  attempt  its 
conservation. 

In  those  cases,  however,  which  present  an  obstinate  suppurating  condi- 
tion, which  iDcrsists  after  the  most  thorough  antiseptic  treatment  of  the  pulp- 
canals,  the  abscess- cavity,  and  the  fistulous  tract,  radical  treatment  becomes 
necessary.  This  may  comprehend,  first,  the  curettement  of  the  fistulous  tract 
and  the  abscess- cavity ;    second,  the  amputation  of  the  apical  end  of  the 


DENTO-ALVEOLAR   ABSCESS.  487 

root  in  situ ;  third,  the  extraction  of  the  tooth,  amputation  of  the  apical 
end  of  the  root,  sealing  of  the  canal,  and  replantation  of  the  tooth. 

Curettement  of  the  abscess-cavity  and  the  fistulous  tract  is  often  employed 
to  stimulate  the  healing  process  in  indolent  ulcerations  and  abscesses.  The 
object  of  this  procedure  is  to  change  the  indolent  character  of  the  granu- 
lating process  into  one  of  an  active  character,  and  thus  promote  the  heal- 
ing process. 

The  procedure  is  as  follows  :  first  inject  a  few  minims  of  a  two  or  four 
per  cent,  solution  of  cocaine  hydrochlorate,  eucaine,  or  chloretone  into  the 
pus- cavity  through  the  fistulous  tract.  As  soon  as  the  parts  have  become 
anaesthetic,  which  will  be  in  from  three  to  five  minutes,  slit  open  the  fistula 
to  its  base  or  connection  with  the  abscess- cavity  ;  enlarge  the  opening  in 
the  alveolar  plate  sufficiently  to  admit  a  good-sized  straight  spoon  exca- 
vator. Carefully  examine  the  apex  of  the  root  for  any  rough  or  denuded 
points,  and  if  none  exist  the  case  may  be  considered  as  offering  a  fair 
chance  of  being  cured.  The  next  step  is  to  thoroughly  curette  the  whole 
surface  of  the  abscess- cavity  with  the  spoon  excavator,  after  which  the 
debris  and  blood  may  be  washed  away  and  the  cavity  packed  with  a  strip 
of  boric  acid  gauze  or  carbolized  gauze.  The  root-canal  should  have  been 
previously  sterilized  and  packed  with  an  antiseptic  dressing,  or  the  canal 
may  be  permanently  filled  with  gutta-percha.  In  the  opinion  of  the 
writer  the  better  plan  is  to  permanently  fill  the  root-canal  first,  and  then 
at  the  same  sitting,  or  one  arranged  a  few  days  later,  proceed  with  the 
operation  of  curettement.  The  after-treatment  of  the  abscess-cavity  con- 
sists of  removing  the  dressing  once  each  day,  thorough  irrigation  with  a 
saturated  boric  acid  solution,  two  per  cent,  carbolic  acid  solution,  or  with 
cinnamon- water,  and  redressing  with  a  strip  of  gauze.  The  gauze  should 
be  packed  lightly  so  as  not  to  injure  the  delicate  granulation-tissue  which 
usually  begins  to  form  immediately  after  the  operation.  As  the  cavity 
grows  smaller  less  and  less  gauze  will  be  required,  and  finally  it  may  be 
left  out  altogether  and  the  external  opening  allowed  to  close.  Irrigation, 
however,  must  be  kept  up  until  the  wound  is  entirely  healed.  Trequent 
use  of  the  irrigating  fluid  should  be  recommended  as  a  mouth-wash,  and 
the  patient  instructed  to  use  it  every  two  hours  during  the  day  and  once 
or  twice  during  the  night  as  a  means  of  controlling  the  septic  condition 
of  the  mouth. 

If,  however,  upon  examining  the  apex  of  the  root  it  is  found  to  be  de- 
nuded and  roughened,  or  covered  with  calcific  deposits,  it  will  be  necessary 
to  amputate  the  diseased  portion  of  the  apex. 

Amputation  of  the  Apex  in  Situ. — Before  undertaking  this  opera- 
tion the  pulp-canal  should  be  thoroughly  sterilized  and  filled  with  gutta- 
percha, and  the  crown-cavity  protected  with  a  filling  of  zinc  oxyphosphate. 
The  fistula  is  then  slit  open  with  a  small  bistoury  down  to  the  apex 
of  the  root,  the  edges  of  the  incision  held  away,  and  a  section  of  the 
alveolar  plate  removed  with  the  trephine  in  the  dental  engine  sufSciently 
large  to  thoroughly  expose  the  apex  of  the  root,  or  a  large  fissure-bur  may 
be  used  for  the  same  purpose,  and  the  opening  in  the  alveolar  plate  en- 
larged by  sweeping  it  around  the  edges.     Hemorrhage  may  be  controlled 


OPERATIVE   DENTISTRY. 

by  packing  the  wound  with  cotton  saturated  with  phenol  sodique  or  tannin 
in  glycerol.  The  apex  of  the  root,  after  the  hemorrhage  has  ceased,  can 
be  readily  seen  through  the  opening.  The  eroded  portion  should  now  be 
amputated  with  a  small,  sharp  fissure-bur,  revolved  at  high  speed  with  the 
dental  engine.  The  edges  of  the  stump  can  be  smoothed  with  a  fine  finish- 
ing-bur, or  with  a  sharp  excavator  or  scaler.  The  cavity  should  next  be 
thoroughly  irrigated,  all  debris  and  blood-clots  removed,  and  the  cavity 
packed  with  a  strip  of  gauze  and  powdered  boric  acid.  The  edges  of  the 
incision  may  be  brought  together  at  the  upper  portion  and  maintained  in 
position  by  one  or  two  sterilized  horse-hair  sutures,  the  end  of  the  gauze 
being  left  at  the  most  dependent  portion  of  the  incision,  where  it  may  be 
grasped  and  removed  after  twenty-four  to  forty-eight  hours,  according  as 
the  circumstances  of  the  case  may  indicate.  Meanwhile  the  moutli  must 
be  frequently  irrigated  with  a  suitable  antiseptic  lotion.  At  the  end  of  a 
couple  of  days  the  dressing  is  removed,  the  cavity  thoroughly  irrigated 
with  antiseptic  solutions,  and  the  patient  instructed  to  keep  the  mouth 
clean  by  the  frequent  use  of  the  antiseptic  mouth- wash  which  has  been 
selected.  Teeth  which  have  been  treated  after  this  method  should  not  be 
filled  with  gold  for  several  months  after  the  operation. 

A  fair  per  cent,  of  the  cases  of  amputation  in  situ  prove  successful, but 

the  writer  is  of  the  opinion  that  the  more  heroic  operation  of  extraction 

and  replantation  (see  following   chapter)  gives  a  larger  percentage  of 

cures  in  obstinate  cases  of  alveolar  abscess  than  the  preceding  method 

of  operation. 

Alveolar  Abscess  associated  with  Deciduous  Teeth. — Little  chil- 
dren are  often  great  sufferers  from  alveolar  abscesses  associated  with  their 
temporary  teeth.  If  the  child  is  timid  and  greatly  afraid  of  being  hurt, 
the  difficulties  presented  by  this  condition  render  the  duty  of  the  operator 
to  relieve  the  little  sufferer  as  quickly  as  possible  a  somewhat  arduous 
task. 

Patience,  gentleness,  and  kindness,  however,  backed  by  a  little  firm- 
ness, will  usually  overcome  the  timidity  of  the  child,  and  in  large  measure 
banish  the  fear  of  being  hurt,  so  that  it  becomes  possible  to  do  all  that  is 
necessary  to  give  the  desired  relief. 

The  suppurative  process  occurring  in  children  is  never  so  severe  as  in 
adults,  as  the  tissues  of  children  are  soft  and  break  down  very  readily 
when  subjected  to  inflammatory  processes.  For  this  reason  the  time  con- 
sumed by  the  pus  in  finding  its  way  through  the  gum  is  much  less  than  in 
the  adult.  And  although  the  pulse  and  the  temperature  may  run  high 
during  the  inflammatory  process,  and  the  swelling  and  congestion  of  the 
tissues  be  very  considerable,  the  suffering  is  not  so  great  as  in  adults. 

The  treatment  of  these  cases  does  not  differ  from  that  already  indi- 
cated. Immediate  relief  may  usually  be  obtained  by  opening  the  abscess 
by  an  incision  in  the  gum.  This  may  be  done  with  so  little  pain  to  the 
child,  if  the  bistoury  with  which  the  incision  is  to  be  made  has  a  keen 
edge,  and  the  attention  of  the  child  is  diverted  to  some. pleasing  subject 
when  the  incision  is  made,  as  to  hardly  attract  its  notice.  When  all  is 
over  the  child  usually  expresses  surprise  that  it  hurt  so  little.     With  chil- 


DENTO-ALVEOLAE  ABSCESS.  489 

dren  who  are  unmanageable  it  becomes  necessary  to  use  a  general  anaes- 
tlietic,  and  under  certain  circumstances  it  is  best  to  extract  the  tooth  rather 
than  to  attempt  its  conservation. 

A  very  large  percentage  of  jDulpless  temporary  teeth  can  be  rendered 
healthy  and  useful  so  long  as  nature  requires  their  service  for  the  purpose 
of  mastication  by  thorough  sterilization  of  the  pulp-canals  and  filling  them 
with  gutta-percha.  Dr.  W.  H.  White  a  few  years  ago  introduced  a  new 
material  for  filling  root-canals  in  children's  teeth  particularly, — viz., 
balsam  del  deserto,  which  it  is  claimed  does  not  in  the  least  interfere  with 
the  resorptive  i^rocess  of  the  roots  of  these  teeth  in  their  exuviation.  It 
is  especially  useful  in  filling  abnormally  large  canals. 

Occasionally  a  case  will  be  presented  in  which  root-fillings  are  not 
tolerated  by  the  tissues.  Such  teeth  should  be  extracted  at  once,  as  re- 
peated inflammation  and  the  formation  of  abscesses '  are  liable  to  cause 
injury  to  the  advancing  tooth. 

Chronic  alveolar  abscesses  are  prone  to  cause  swelling  of,  and  some- 
times metastatic  abscesses  in,  the  cervical  lymphatic  glands  of  children  of 
the  strumous  or  tuberculous  diathesis.  Under  such  circumstances  the 
immediate  extraction  of  these  teeth  is  imperatively  demanded. 

Constitutional  treatment  is  also  demanded  in  these  cases  for  the  build- 
ing up  of  the  bodily  vigor.  Much  can  be  done  for  these  children  by  giving 
them  an  abundance  of  out-door  life  and  plenty  of  wholesome,  nutritious 
food.  Sometimes  di^ugs  are  indicated,  in  the  form  of  cod-liver  oil,  iron, 
arsenic,  beef-peptones,  the  bitter  tonics,  etc.,  but  best  of  all  is  sunlight, 
pure  air,  plenty  of  exercise,  and  the  institution  of  a  scrupulous  hygienic 
condition  of  the  mouth. 


CHAPTEE    XXX. 

REPLANTATION   OF   THE   TEETH. 

Definition. — Eeplantation,  from  the  Latin  replantare,  to  plant  again. 
Eeimplantation,  from  the  Latin  reimplanto,  to  implant  again. 

The  operation  of  replantation  or  reimplantation  of  teeth  is  the  replacing 
of  a  tooth  in  the  alveolus  from  whence  it  had  been  removed  by  accident  or 
by  design. 

Eeplantation  is  practised  at  the  present  time  for  three  conditions  : 

First. — When  a  tooth  has  been  dislodged  by  an  accidental  traumatism, 
such  as  might  result  from  a  fall  or  a  blow. 

Second. — When  a  tooth  has  been  removed  as  a  result  of  an  accidental 
surgical  traumatism,  such  as  the  dislodgement  of  a  tooth  by  the  mouth- 
prop  or  mouth-gag  during  the  administration  of  a  general  anoesthetic  pre- 
paratory to  the  extraction  of  a  tooth,  or  the  slipping  of  the  forceps  in  the 
extraction  of  a  tooth,  which  causes  the  dislodgement  of  its  neighbor  or  one 
in  the  opposite  jaw. 

Third. — When  a  tooth  is  the  subject  of  a  persistent  alveolar  abscess 
which  does  not  respond  to  the  ordinary  methods  of  treatment. 

The  degree  of  success  which  attends  the  replantation  of  teeth  depends 
upon  the  presence  and  healthful  condition  of  the  pericementum,  the 
length  of  time  that  the  tooth  has  been  removed  from  its  alveolus,  the 
physical  condition  of  the  patient  at  the  time  of  the  operation,  the  immo- 
bility of  the  tooth  during  the  process  of  forming  its  new  attachments,  and 
the  hygienic  condition  of  the  mouth. 

The  discussion  of  the^rs^  and  second  conditions  will  be  reserved  for  the 
chapter  on  '' Dislocation  of  the  Teeth." 

The  treatment  of  persistent  alveolar  abscess  by  extraction  and  re- 
plantation is  generally  practised  as  a  dernier  ressort  when  all  other  methods 
have  failed. 

Obstinate  alveolar  abscesses  are  usually  caused  by  a  crooked  root,  an 
abnormally  small  root-canal  which  makes  it  impossible  to  remove  or  render 
innocuous  the  retained  septic  pulp -material,  or  it  is  caused  by  perfora- 
tions of  the  root  made  in  attempts  to  open  small  root-canals,  calcareous 
deposits  upon  the  apex  of  the  apical  end  of  the  root,  or  erosion  of  the 
apical  end  of  the  root,  which  is  accompanied  by  a  more  or  less  i)ersistent 
discharge  of  pus,  either  through  the  external  or  internal  plate  of  the 
alveolar  process  or  through  the  alveolus  at  the  neck  of  the  tooth. 

Occasionally  cases  will  be  found  in  which  no  discharges  are  present, 
but  instead  a  chronic  induration  of  the  surrounding  tissues  ;  or,  as  in  the 
superior  teeth,  the  discharges  may  find  their  way  into  the  antrum  of  High- 
more  or  the  anterior  nasal  passages,  and  possibly  mislead  the  operator  into 
490 


REPLANTATION  OF  THE  TEETH.  491 

the  belief  that  he  has  a  case  of  empyema  of  the  antrum  or  of  ozsena  to 
deal  with.* 

These  teeth  are  usually  sooner  or  later  condemned  as  worthless  mem- 
bers of  the  economy,  and  are  removed. 

Many  of  these  teeth  with  suitable  treatment  may  be  rendered  healthy 
and  useful  for  an  indefinite  period. 

Replantation  is  only  admissible  in  the  anterior  teeth,  including  the 
bicuspids.  The  molars  are  capable  of  being  replanted  only  in  exceptional 
cases  when  there  is  fusion  of  the  roots  and  they  assume  a  conical  form, 
and  occasionally  a  lower  molar  when  the  roots  are  perpendicular  to  the 
crown. 

It  will  be  generally  conceded  that  attempts  to  cure  such  cases  as  those 
just  mentioned  by  the  ordinary  methods  usually  prove  unsuccessful,  and 
that  eventually  the  teeth  are  lost.  This  results  from  the  fact  that  such 
operations  are  largely,  perforce,  only  guesswork.  If  the  root  is  curved  at 
a  more  or  less  acute  angle  it  is  difficult  to  follow  the  canal  with  the  broach 
or  Donaldson  bristle,  and  many  times  quite  impossible,  or  if  the  canal  is 
abnormally  small,  the  finest  Donaldson  bristle  may  not  enter  it  at  all. 
Eeaming  the  canal  is  unsafe,  and  under  these  conditions  the  various  anti- 
septic fluids  and  liquid  filling- materials  are  unsatisfactory  because  they  do 
not  always  penetrate  to  the  end  of  the  canal,  and  consequently  septic 
material  remains  in  the  pulp -canal  and  keeps  up  a  constant  irritation. 

In  cases  of  erosion  of  the  apical  end  of  the  root,  amputation  of  this 
portion  in  situ  is  frequently  unsuccessful  in  curing  the  disease  owing  to  the 
difficulties  in  smoothing  the  stump  and  perfectly  filling  the  apical  foramen. 

The  same  may  be  said  of  attempts  to  plug  perforations  in  the  sides  of 
the  root. 

Roughened  surfaces  and  foreign  substances  are  not  kindly  borne  by  the 
tissues  which  surround  the  roots  of  the  teeth  ;  it  is  therefore  imperative 
that  all  such  hinderances  to  a  return  to  the  normal  condition  be  reduced  to 
a  minimum.  For  these  reasons  it  would  seem  preferable  to  extract  and 
replant  such  teeth  if  they  do  not  speedily  prove  amenable  to  treatment  by 
the  usual  methods ;  for,  with  the  tooth  in  the  hand,  the  root  can  be 
minutely  inspected,  and  any  eroded  portion  amputated  and  the  surfaces 
finely  polished.  The  pulp-canal  can  be  reamed  out  and  cleansed  without 
the  fear  of  perforating  its  sides,  the  canal  filled  and  the  ajDical  foramen  or 
a  perforation  plugged  with  gold  and  carefully  finished,  and  the  whole  thor- 
oughly sterilized.  ISTone  of  these  operations  are  possible  with  the  same 
degree  of  perfection  while  the  tooth  is  in  situ ;  they  must,  perforce,  be  more 
or  less  imperfect,  and  just  in  that  degree  will  they  produce  irritation  and 
the  more  serious  inflammatory  processes. 

The  question  might  very  properly  be  asked,  Are  the  operations  of  re- 
plantation and  transplantation  of  freshly  extracted  teeth  having  the  peri- 
cementum attached  founded  upon  physiologic  law  and  sound  surgical 
principles  ?  The  answer  is.  Yes ;  quite  as  much  so  as  are  the  operations 
of  skin  and  bone  grafting,  and  no  one  condemns  these.     Union  with  the 


*  Dental  Cosmos,  vol.  xxxiv.  p.  464. 


492  OPERATIVE   DENTISTEY. 

tissues  witli  wliicli  they  are  placed  in  contact  is  the  result  of  the  same  vital 
I)rocesses  ;  the  surgical  conditions  are  nearly  identical  in  each  of  them,  and 
success  is  as  certain  in  the  one  as  in  the  other,  provided  the  same  aseptic 
conditions  can  be  maintained  until  union  is  complete. 

The  failure  of  replanted  teeth  to  unite  with  their  alveoli  is  much  less 
common  than  with  transplanted  teeth ;  at  least,  the  personal  observation 
of  the  writer  bears  out  this  statement.  The  immediate  cause  of  failure  is 
usually  suppurative  inflammation,  induced  either  by  mobility  of  the  tooth, 
which  constantly  breaks  up  the  attachment  of  the  plastic  exudate,  or  septic 
conditions  of  the  tooth  or  of  its  alveolus  at  the  time  of  the  operation,  or 
inoculation  afterwards  from  a  septic  condition  of  the  mouth. 

The  failures  which  occur  later — viz.,  after  attachment  has  taken  place — 
are  more  difficult  to  understand. 

In  these  cases  the  surfaces  of  the  roots  are  attacked  by  the  osteoclasts, 
and  gradually  honey-combed  or  masses  of  pericemental  tissue  and  dentin 
are  dissolved  at  various  locations  about  the  apex,  leaving  large  cavernous 
excavations  with  sharp  edges.  Suppuration  accompanies  or  follows  the 
work  of  the  osteoclasts ;  the  tooth  becomes  loose,  and  is  sooner  or  later 
expelled  from  the  jaw  as  a  foreign  substance. 

In  explanation  the  writer  would  venture  the  oxiinion  that  these  phenom- 
ena are  due  to  irritation  induced  by  septic  conditions  resulting  from  decom- 
position of  the  organic  material  contained  in  the  dentine,  and  that  in  the 
form  of  a  gas  or  effluvium  it  penetrates  the  cementum,  and  coming  in 
contact  with  the  pericementum  and  surrounding  tissues,  sets  up  this  retro- 
grade metamorjDhosis. 

There  are  certain  individuals  for  whom  it  would  not  be  wise  to  under- 
take this  operation, — viz.,  those  suffering  from  general  anaemia,  tubercu- 
losis, and  syphilis.  Such  individuals  are  never  good  subjects  for  surgical 
operations,  as  their  tissues  are  very  irritable,  do  not,  as  a  rule,  heal 
readily,  and  are  prone  to  suppuration  ;  consequently  replantation,  trans- 
plantation, and  implantation,  if  performed  upon  such  persons,  are  likely  to 
prove  unsuccessful. 

Many  of  the  failures  from  these  operations  have  been  associated  with 
one  or  the  other  of  these  diseases.  Great  care  should  therefore  be  exer- 
cised in  the  selection  of  the  cases  upon  which  to  operate.  Carelessness  in 
this  regard  can  only  result  in  failure.  Of  the  more  than  forty  operations 
of  this  character  which  it  has  been  the  privilege  of  the  writer  to  perform, 
it  has  been  thus  far  his  misfortune  to  record  only  a  single  failure,  although 
they  have  comprised  all  grades  and  durations  of  the  disease,  several  of 
very  long  standing,  ranging  from  five  to  fifteen  years. 

The  character  of  the  union  which  takes  place  between  the  root  of  the 
replanted  tooth  and  its  alveolus  has  not  so  far  been  positively  demon- 
strated. The  writer  therefore  feels  that  he  may  o£fer  a  few  thoughts  which 
may  tend  towards  an  elucidation  of  this  question. 

Applying  the  methods  used  in  physical  diagnosis  to  these  cases,  we  find 
that  percussion  gives  the  most  marked  signs. 

Taking  the  percussion  note  of  normal  teeth,  produced  by  striking  the 
tooth  with  a  steel  instrument,  as  the  standard  of  pitch,  we  find  that  as 


EEPLANTATION  OF  THE  TEETH.  493 

inflammatory  conditious  of  tlie  alveolus  advance  the  percussion  note  be- 
comes lower  and  duller,  while,  on  the  other  hand,  as  these  symptoms  sub- 
side the  note  assumes  a  clearer  and  higher  pitch.  This  lowering  of  the 
tone  is  doubtless  the  result  of  a  thickening  of  the  pericemental  membrane 
and  its  increased  vascularity.  The  percussion  note  given  by  a  large  per- 
centage of  replanted  teeth  a  few  months  after  the  operation,  or  when  union 
is  complete,  is  much  clearer  and  higher  pitched  than  that  of  the  adjoining 
teeth.  This  is  more  noticeable  in  the  superior  than  in  the  inferior  teeth, 
on  account  of  the  greater  resonance  of  the  superior  maxillae. 

These  facts  would  seem  to  indicate  a  bony  union  in  these  cases  between 
the  root  and  its  alveolus. 

It  would  also  seem  probable  that  the  locations  at  which  this  anchylosis 
would  most  likely  occur  would  be  where  the  pericementum  had  been 
destroyed  or  the  cement- tissue  partially  removed  ;  and  there  seems  no  good 
reason  why  under  these  conditions  reunion  may  not  take  place  in  a  some- 
what similar  manner  to  that  which  occurs  in  fractured  bones. 

In  some  cases  the  percussion  note  is  normal,  this  would  indicate  a  nor- 
mal reunion  of  the  pericementum  with  the  alveolus  ;  but  when  the  percus- 
sion note  is  lower  and  duller,  it  would  be  certain  evidence  of  an  indurated 
pericementum  or  other  inflammatory  symptoms. 

To  insure  success  in  these  oi:)erations  the  following  suggestions  should 
be  observed : 

1.  Exclude  anaemic,  tubercular,  and  syphilitic  cases. 

2.  Secure  thorough  aseptic  conditions  of  the  surfaces  of  the  root  and 
pulp-canal  by  washing  and  immersing  in  bichloride  of  mercury  solution, 
1  to  500  of  water. 

3.  Amputate  and  smooth  all  eroded  surfaces,  but  sacrifice  as  little  of 
the  pericementum  as  possible.     This  is  very  important. 

4.  Hermetically  seal  the  pulp-canal  and  apical  foramen,  and  any  per- 
forations that  may  exist,  with  gold  fillings. 

5.  Curette  the  abscess-cavity,  remove  the  blood- clot  from  the  alveolus, 
and  wash  both  with  the  bichloride  of  mercury  solution  before  replanting 
the  tooth.  This  is  the  only  treatment  of  the  abscess-cavity  and  of  the 
alveolus  that  will  be  required. 

6.  Secure  immobility  of  the  tooth  by  a  ligature  or  an  interdental  splint 
until  union  has  taken  place.  An  impression  of  the  teeth  of  that  part  of 
the  jaw  to  be  operated  upon  should  be  taken  before  the  tooth  is  extracted, 
and  a  splint  of  gold  made  to  include  one  or  two  teeth  ujDon  either  side  of  it. 
After  the  tooth  has  been  replanted,  the  splint  is  applied  and  secured  in 
position  with  zinc  oxyphosphate  cement,  and  allowed  to  remain  for  from 
four  to  six  weeks. 


CHAPTEE    XXXL 

TRANSPLANTATION   AND   IMPLANTATION   OF   THE   TEETH. 

Definition. — Transplantation  (Latin,  trans,  across  ;  plantare,  to  plant), 
the  operation  of  grafting  tissue  from  one  part  of  the  body  to  another  part 
of  the  same  body,  or  from  the  body  of  one  individual  to  that  of  another. 

The  transplantation  of  teeth  is  the  operation  of  transferring  a  tooth 
from  one  alveolus  in  the  mouth  of  an  individual  to  another  alveolus  in  the 
same  mouth,  or  of  transferring  a  tooth  from  the  mouth  of  one  individual 
to  that  of  another. 

The  operation  of  transplanting  teeth  was,  during  the  days  of  John 
Hunter,  much  more  extensively  practised  than  it  is  at  the  present  day. 
The  study  of  the  literature  of  that  period  and  of  the  intervening  years 
shows  that  as  far  back  as  1783  the  operation  was  falling  into  disuse,  and  in 
1810  it  was  referred  to  as  being  consigned  to  oblivion.  The  reasons  which 
were  assigned  for  giving  up  the  operation  were  (1)  the  great  danger  of 
transmitting  specific  diseases-  like  syphilis,  (2)  the  frequent  occurrence  of 
alveolar  abscess,  (3)  the  loss  of  the  tooth  after  a  few  years  from  loosening 
or  resorption  of  its  root,  and  (4)  objections  were  raised  to  the  operation  on 
moral  grounds,  as  the  poor  sold  their  teeth  to  the  rich  for  a  price. 

During  the  last  two  decades  the  operation  has  been  revived,  and  upon 
the  whole  has  given  somewhat  better  results  than  those  recorded  a  hundred 
years  ago.  The  teeth  which  are  used  are  usually  sound  teeth  or  healthy 
roots  that  have  been  removed  in  the  operation  of  regulating  the  teeth  or 
to  make  room  for  an  artificial  denture.  The  introduction  of  antiseptic 
methods  in  operative  surgery  has  made  itx)0ssible  to  entirely  prevent  the 
inflammatory  symptoms  and  the  formation  of  alveolar  abscesses  which 
were  before  this  time  so  common  as  a  sequel  of  the  operation.  The 
danger  of  transmitting  specific  diseases  has,  however,  not  been  overcome, 
although  no  doubt  greater  care  is  exercised  in  the  selection  of  the  teeth 
that  are  to  be  used  for  transplanting  by  inquiring  more  carefully  into  the 
history  and  x)hysical  condition  of  the  individual  from  whose  mouth  the 
tooth  was  taken.  One  case  has,  nevertheless,  been  reported  recently  in 
which  syphilis  was  said  to  have  been  transmitted  by  the  transplantation 
of  a  tooth  taken  from  the  mouth  of  a  syphilitic  subject. 

The  tendency  to  ultimate  loosening  of  the  tooth  and  resorption  of  its 
root  after  a  few  years  remains  the  same,  and  there  seems  to  be  no  way  to 
prevent  these  untoward  results.  Teeth  which  have  been  treated  by  the 
most  complete  aseptic  methods  are  equally  liable  to  be  lost  by  these 
morbid  conditions  as  those  which  had  not  been  so  treated. 

Eeplanted  teeth  and  teeth  transplanted  from  one  alveolus  to  another  of 
the  same  mouth  give  better  results,  in  the  observation  and  experience  of 
the  writer,  than  do  teeth  transplanted  from  the  mouth  of  one  indivdual  to 
that  of  another. 
494 


TRANSPLANTATION    AND    IMPLANTATION    OF   THE   TEETH.  495 

The  operation  is  applicable  only  to  the  ten  anterior  or  single-rooted 
teeth.  It  will  be  seen,  therefore,  that  the  operation  is  confined  to  rather 
narrow  limitations,  the  confines  of  which  cannot,  with  any  assurance  of 
success,  be  overstepped. 

The  same  general  conditions  that  promote  success  or  failure  in  replanted 
teeth  are  operative  in  transplanted  teeth, — viz.,  the  presence  of  healthful 
or  morbid  condition  of  the  pericementum,  the  length  of  time  that  the 
tooth  has  been  removed  from  its  alveolus,  the  physical  condition  of  the 
patient  at  the  time  of  the  operation,  the  hygienic  or  non-hygienic  con- 
dition of  the  mouth,  the  adaptability  or  non-adaptability  of  the  tooth  to 
its  new  alveolus,  the  healthful  or  morbid  condition  of  the  new  alveolus, 
and  the  mobility  or  immobility  of  the  tooth  during  the  formation  of  its 
new  attachment. 

The  most  favorable  period  in  which  to  perform  the  operation  of  trans- 
plantation is  during  youth  and  early  adult  life,  although  it  may  be  suc- 
cessfully performed  at  any  period  provided  the  patient  is  in  vigorous 
health. 

In  the  selection  of  a  tooth  for  transplantation,  one  should  be  chosen 
which  is  as  near  as  possible  of  the  same  age  as  the  tooth  which  is  to  be 
replaced.  Teeth  which  are  younger  than  the  one  to  be  replaced  are,  how- 
ever, more  likely  to  form  a  healthy  union  with  the  new  alveolus  than  those 
which  are  older. 

The  practice  of  selecting  teeth  which  have  been  extracted  for  a  con- 
siderable time,  where  nothing  is  known  of  their  history  or  of  the  physical 
condition  of  the  patient  from  whom  they  were  taken,  should  be  severely 
criticised  for  the  reasons  already  mentioned.  Too  much  care  cannot  be 
exercised  in  this  direction.  When  a  suitable  sound,  fresh  tooth  cannot  be 
secured,  a  tooth  with  a  carious  crown  but  healthy  root  may  be  selected, 
and  an  artificial  crown  of  proper  color  and  form  grafted  upon  the  root  by 
any  of  the  various  methods  of  crowning. 

It  is  better,  also,  in  selecting  the  tooth,  to  choose  one  with  a  slightly 
larger,  rather  than  a  smaller,  root  than  the  tooth  to  be  replaced,  as  it  is  an 
easy  matter  with  suitable  burs  and  drills  to  enlarge,  deepen,  or  change  the 
shape  of  the  alveolus  to  fit  the  tooth.  When  the  root  is  too  small  to  fit 
the  alveolus  immobility  cannot  be  secured,  and  as  a  consequence  a  good 
union  does  not  take  place. 

The  best  results  are  obtained  by  completing  the  operation  at  the  same  sit- 
ting. The  tooth  to  be  replaced  should  first  be  extracted,  care  being  exercised 
not  to  fracture  the  alveolus  or  unnecessarily  wound  the  gum.  The  tooth  to  be 
replanted  is  next  extracted,  the  pulp-canal  opened,  the  pulj)  extirpated, 
the  canal  filled  with  gutta-percha,  and  the  apical  foramen  and  the  opening 
in  the  crown  plugged  with  gold.  The  whole  operation  should  be  performed 
according  to  the  strictest  aseptic  methods.  (See  preparation  of  the  tooth 
for  replantation,  in  preceding  chapter.) 

The  alveolus  should  then  be  shaped  to  receive  the  new  tooth,  the 
alveolus  and  tooth  thoroughly  washed  with  a  solution  of  mercuric  bi- 
chloride, 1  to  1000  of  water.  The  tooth  may  now  be  placed  in  position 
and  retained,  if  necessary,  with  a  ligature,  an  impression  taken  of  this 


496  •  OPERATIVE    DENTISTRY. 

section  of  the  mouth,  and  a  metal  splint  constructed  which  will  cover  the 
transplanted  tooth  and  one  upon  either  side  of  it,  and  cemented  in  place 
with  zinc  oxy phosphate. 

The  onlj^  after-treatment  that  is  necessary  is  that  comprehended  in  a 
thoroughly  clean  condition  of  the  mouth,  secured  by  careful  brushing  and 
the  frequent  use  of  antiseptic  solutions.  The  splint  may  be  permitted  to 
remain  in  position  for  a  period  ranging  from  four  to  twelve  weeks. 

Method  of  Union. — The  union  which  takes  place  between  the  alve- 
olus and  a  fresh  tooth  in  which  the  pericementum  is  intact  over  the  whole 
surface  of  the  root  would  seem  to  be  by  a  normal  process,  like  that  which 
takes  place  between  these  tissues  in  a  tooth  which  has  been  dislocated  by 
accident  and  immediately  replanted. 

In  those  cases,  however,  in  which  the  pericementum  has  been  removed 
in  part  by  shortening  of  the  root  or  by  disease  the  union  seems  in  some 
cases  to  be  bony,  in  others  fibrous. 

Mitscherlich  transplanted  a  tooth  in  a  dog,  and  after  six  weeks  ex- 
amined it,  and  found  that  a  considerable  portion  of  the  pericementum  had 
disappeared,  that  resorption  had  taken  place  at  several  locations,  followed 
by  calcification  of  the  osteoclasts  and  the  formation  of  new  tissue  within 
the  spaces  or  cavities  formed  by  the  resorptive  process.  This  new-formed 
tissue  was  continuous  with  the  bone  of  the  alveolus,  and  held  the  tooth 
firmly  within  its  alveolus. 

The  notion  that  has  been  held  by  some  operators  that  the  pericementum 
of  the  tooth  after  it  has  been  extracted  for  some  considerable  time  and 
had  become  dried  and  dead  was  after  transplantation  revivified  has  no 
foundation  in  fact,  and  is  directly  opposed  to  all  physiologic  law.  The 
attachment  which  occurs  between  such  teeth  and  the  alveolus  is,  in  all 
probability,  a  semi-mechanical  one,  such  as  was  demonstrated  by  Mitscher- 
lich in  his  experiment  upon  the  dog. 

Prognosis. — Eesorption  of  the  roots  of  transplanted  teeth  usually  occurs 
at  an  earlier  or  later  period,  ranging  from  a  few  months  to  four  or  five 
years,  although  in  exceptional  cases  they  have  remained  successfal  for  a 
considerably  longer  period  ;  the  late  Dr.  Morrison  reported  cases  which 
were  successful  after  eleven  years. 

IMPLANTATION   OF   TEETH. 

Definition. — Implantation  (Latin,  invplantatio,  from  in,  in,  and  plan- 
tare,  to  set),  the  act  of  setting  in.  Applied  to  surgery  it  may  be  the 
engrafting  of  epidermis  from  the  skin  of  one  person  upon  the  body  of 
another,  the  surgical  repair  of  a  wounded  intestine  by  uniting  the  divided 
ends,  or  the  setting  or  transplanting  of  a  tooth  taken  from  the  jaw  of 
one  person  and  inserted  into  an  artificial  alveolus  made  in  the  jaw  of 
another. 

Implantation  of  teeth  is  an  operation  of  modern  times,  suggested  by 
Dr.  Younger,  of  San  Francisco,  California,  and  when  first  introduced 
attracted  considerable  attention  from  the  profession.  Many  operations 
were  made  with  little  regard  to  the  physical  condition  of  the  persons 
operated  upon  or  to  the  hygienic  conditions  of  the  mouth.    Teeth  were 


TEANSPLANTATIOJS"   AND    IMPLANTATION    OF    THE   TEETH.  497 

implanted  for  iDersons  suffering  with  syphilis,  tuberculosis,  and  other  con- 
stitutional diseases,  and  certain  vicious  habits  like  alcoholic  intemperance, 
which  have  a  tendency  to  lower  the  recuperative  powers  of  the  tissues  and 
favor  the  suppurative  process.  Consequently  there  were  very  many  more 
failures  than  would  in  all  j^robability  have  occurred  had  the  cases  selected 
for  the  operation  been  more  carefully  chosen. 

The  only  persons  upon  whom  the  operation  should  be  performed  are 
those  who  are  in  vigorous  health,  whose  occupations  do  not  call  for  an  un- 
usual expenditure  of  nerve  force,  and  who  are  accustomed  to  keeping  their 
mouths  in  the  very  best  hygienic  condition. 

Requirements  for  the  Operation. — The  successful  performance  of 
the  operation  of  implantation  requires  u]3on  the  part  of  the  operator  an 
intimate  knowledge  of  the  anatomy  of  the  parts  involved  and  their  rela- 
tionship to  other  parts.  It  must  be  constantly  borne  in  mind  that  after 
resorption  of  the  alveolar  process  has  taken  place  the  depth  of  the  bone 
is  very  much  less  than  before  the  tooth  had  been  extracted.  In  some  cases 
the  bone  which  intervenes  between  the  apices  of  the  roots  and  the  nasal 
fossa  or  the  antrum  of  Highmore  is  extremely  thin,  often  not  more  than 
one-fourth  to  three-eighths  of  an  inch  in  thickness,  while  in  extreme  cases 
it  rarely  exceeds  half  an  inch  in  thickness. 

It  is  necessary,  therefore,  to  exercise  great  care,  in  forming  the  artificial 
alveolus  in  the  upper  jaw,  not  to  i3enetrate  the  nasal  fossa  or  the  antrum 
of  Highmore,  or  to  encroach  upon  the  anterior  palatine  canal,  which  carries 
the  anterior  palatine  artery,  vein,  and  nerve,  when  forming  an  alveolus  for 
a  central  incisor.  When  resorption  of  the  alveolar  process  has  been  very 
considerable,  it  is  often  exceedingly  difficult  to  so  form  the  artificial 
alveolus  as  to  give  the  tooth  its  right  position  and  inclination  in  the  arch 
and  preserve  a  bony  wall  for  the  labial  surface  of  the  alveolus.  This  diffi- 
culty is  more  often  encountered  in  the  region  of  the  central  and  lateral 
incisors  than  in  that  of  the  cuspids. 

Should  the  operator  be  so  unfortunate  as  to  penetrate  the  nasal  fossa  or 
the  maxillary  sinus,  extreme  care  must  be  exercised  not  to  infect  the  sinus. 
To  guard  against  infection  the  artificial  alveolus  should  be  immediately 
plugged  with  a  single  strip  of  antiseptic  gauze,  which  should  remain  until 
the  tooth  is  ready  to  be  inserted  into  its  new  alveolus. 

To  guard  against  the  possibility  of  the  apex  of  the  tooth  passing  into 
the  nasal  fossa  or  the  antrum  under  these  circumstances,  the  depth  of  the 
bony  socket  should  be  measured  and  the  root  shortened  to  correspond  with 
its  depth. 

The  preparation  of  the  tooth  selected  for  implantation  should  be  the 
same  as  for  a  tooth  which  is  to  be  replanted  or  transplanted. 

The  next  step  in  the  preparation  for  the  operation  is  the  construction 
of  a  metal  splint  to  secure  the  tooth  in  position  while  union  is  taking 
place.  This  is  done  by  taking  an  impression  of  the  space  to  be  occupied 
by  the  implanted  tooth  and  the  teeth  upon  either  side  of  it.  A  plaster 
cast  is  made  from  this  impression,  a  bite  is  taken,  and  the  whole  placed  in 
an  articulator.  A  suitable-sized  socket  is  then  drilled  in  the  plaster  cast, 
the  root  of  the  tooth  adjusted  therein,  and  the  proper  occlusion  secured. 

32 


498 


OPERATIVE    DENTISTRY. 


From  the  plaster  cast,  with  the  tooth  retained  in  it,  a  die  is  made  and  the 
metal  splint  swaged  over  it. 

The  tooth  is  then  thoroughly  cleansed  and  placed  in  a  suitable  disin- 
fecting solution,  1  to  1000  bichloride,  or  a  saturated  boric  acid  solution, 
and  kept  at  a  temperature  of  100°  to  110°  F.  until  the  artificial  alveolus 
has  been  made  in  the  jaw. 

Method  of  Operation. — The  first  step  in  the  operation  is  to  make  an 
incision  in  the  gum- tissue  down  to  the  bone.     The  form  of  this  incision 
will  depend  largely  upon  the  individual  preference  of 
Fig.  578.  the  operator,  the  main  object  being  to  conserve  as 

much  of  the  firm  tissue  as  possible.  Some  operators 
employ  a  circular  incision  made  with  the  EoUin  circu- 
lar knives  (Fig.  578),  others  i^refer  a  crucial  incision 
(X),  which  makes  four  flaps ;  others  an  incision  in 
form  of  the  letter  H,  which  makes  two  flaps ;  while 
still  others  prefer  to  employ  a  U-like  or  staple-like 
(  U  )  incision,  which  forms  a  single  flap. 

In  the  X  or  crucial  incision  the  centre  of  the  cross 

should   correspond  with  the   centre   of  the  alveolar 

border,  and  the  flaps  are  to  be  turned  back  out  of  the 

way  of  the  instruments  which  are  used  to  form  the 

Circular  knives.  socket  in  the  bone. 

In  the  letter  H  incision  the  upright  lines  of  the 
incision  are  made  across  the  alveolar  border,  close  to  the  approximal  sur- 
faces of  .the  teeth  upon  the  mesial  and  distal  sides  of  the  space  to  be  filled 
by  the  implanted  tooth,  while  the  bar  or  horizontal  incision  should  con- 
nect the  upright  incisions  through  the  centre  of  the  alveolar  border. 

In  the  U-like  or  staj^le-like  (U)  incision  the  upright  incisions  are 
made  across  the  alveolar  border,  close  to  the  approximating  teeth,  while 
the  curved  or  the  straight  incision  made  to  connect  the  upright  incisions 
are  to  be  made  at  the  lingual  border  of  the  alveolus. 

The  incisions  having  been  made,  the  next  step  in  the  operation  is  to  lift 
the  flaps  from  the  bone,  and  in  doing  this  care  should  be  taken  to  get  be- 
neath the  periosteum,  so  that  this  membrane  will  be  left  adherent  to  the 
gum-tissue,  as  by  so  doing  the  periosteal  layer  of  the  flaps  will,  when  it 
comes  in  contact  with  the  root  of  the  imjplanted  tooth,  assist  in  forming  a 
new  alveolar  border.  Delicate  periosteotomes  for  this  purpose  may  be 
made  from  selected  enamel  chisels  by  rounding  the  cutting  edges. 

The  flaps,  having  been  lifted  from  the  bone,  should  be  held  out  of  the 
way  by  a  delicate  spring  tenaculum-speculum  during  the  forming  of  the 
new  alveolus.  The  greatest  care  should  be  taken  not  to  bruise  the  edges 
of  the  flaps,  otherwise  inflammation  and  sloughing  of  the  borders  or  of  the 
entire  flap  may  follow. 

Various  instruments  have  been  suggested  for  the  purpose  of  forming 
the  socket  in  the  bone.  The  first  instruments  made  for  this  purpose  were 
the  Younger  trephines ;  these  have  since  been  improved  by  Dr.  W.  W. 
Walker,  of  'New  York,  and  are  now  made  with  a  set-screw  collar  which 
slides  upon  the  shaft  of  the  instrument  (Fig.  579),  and  can  be  set  at  any 


TRANSPLANTATION    AND    IMPLANTATION    OF   THE   TEETH. 


499 


point  to  correspond  with  the  desired  depth  of  the  alveolus.  Instruments 
of  this  character,  however,  need  to  be  supplemented  with  others  which 
cut  ui3on  the  side,  as  with  the  trephine  alone  the  alveolus  cannot  be  x^rop- 
erly  shaped  or  the  core  removed. 

The  reamers  designed  by  Dr.  Younger  (Fig.  580)  for  this  purpose  have 
a  serious  disadvantage  in  that  they  are  inclined  to  clog.  The  spiral 
knives  of  Dr.  Eollin  (Fig.  581)  are  a  decided  improvement  over  the 
Younger  reamers,  in  that  they  are  not  so  liable  to  clog  and  cut  much 
more  rapidly.  The  combination  drill  and  reamer  instruments  (Fig.  582) 
of  Dr.  Ottolengui,  of  New  York,  are  the  best  of  this  series  of  instruments, 
in  that  they  cut  very  freely  and  rapidly,  do  not  clog,  and  are  provided 
with  a  safety  collar  that  can  be  set  to  suit  any  depth  of  alveolus  that  it 
may  be  desired  to  make. 

Fig.  581. 


Fig.  579. 


Fig.  580. 


Fig.  582. 


Younger- Walker  trephines. 


Younger  reamers. 


The  Ottofy  spiral  crib-knife  is  also  a  valuable  instrument,  as  it  cuts 
with  great  rapidity  and  does  not  clog.  The  spiral  osteotomes  of  Dr.  M.  H. 
Cryer,  of  Philadelphia,  are  designed  for  the  same  purpose,  and  are  the 
most  rapid-cutting  instrument  of  the  series,  and  if  x^ermitted  to  run  freely 
they  do  not  clog.  Long-shanked,  coarse-cut  engine-burs  are  also  useful 
for  making  any  slight  changes  that  may  be  required  in  the  shape  or  depth 
of  the  alveolus. 

During  the  process  of  forming  the  alveolus  the  parts  should  be  fre- 
quently irrigated  with  an  antiseptic  solution,  preferably  a  saturated  solu- 
tion of  boric  acid  in  water  or  the  Thiersch  solution.  After  the  proper 
depth  has  been  reached,  and  during  the  x>rogress  of  shaping  the  alveolus, 
the  tooth  should  from  time  to  time  be  inserted  until  the  proper  adjust- 
ment to  the  socket  and  the  position  in  the  arch  has  been  secured.  Another 
important  feature  of  the  operation  is  to  secure  a  proper  occlusion,  but  it  is 
better  to  have  the  tooth  a  trifle  too  short  than  by  ever  so  small  a  fraction 
too  long,  for  if  the  pressure  of  the  jaws  comes  entirely  upon  the  implanted 
tooth,  inflammatioii  is  liable  to  follow  as  a  consequence  of  the  mechanical 
irritation. 


500  OPERATIVE   DENTISTRY. 

As  soon  as  hemorrhage  has  ceased,  the  month  and  the  socket  should  be 
irrigated  with  a  1  to  1000  mercuric  bichloride  solution,  the  tooth  washed 
in  the  same  solution  and  then  placed  in  position,  the  parts  dried,  and  the 
splint  cemented  in  place.  As  soon  as  the  cement  has  set  the  surplus  should 
be  removed,  the  parts  again  irrigated  with  the  bichloride  solution,  and  the 
edges  of  the  gum  flap  nicely  adjusted  to  the  cervix  of  the  tooth.  If  the 
corners  of  the  flaps  are  inclined  to  fall  away — evert — from  the  cervix,  a 
suture  of  prepared  horse-hair  may  be  passed  through  each  labial  and  lin- 
gual corner  and  tied  between  the  teeth.  The  sutures  should  be  removed 
on  the  third  or  fourth  day.  The  after-treatment  should  consist  of  frequent 
irrigations  of  the  mouth  with  antiseptic  solutions  and  careful  removal  of 
food  debris  from  around  the  seat  of  the  operation,  and  such  other  means  as 
will  secure  the  most  perfect  hygienic  condition  of  the  mouth. 

Prognosis. — ImiDlanted  teeth,  like  transplanted  teeth,  sooner  or  later 
are  lost  by  resorption  of  their  roots.  Many  cases  of  implanted  teeth,  how- 
ever, never  formed  any  kind  of  union  as  the  result  of  suppuration  which 
immediately  followed  the  operation  ;  others  formed  a  slight  attachment  to 
the  alveolus  and  loosened  after  a  few  weeks  or  months,  and  dropped  out  or 
were  removed  with  the  fingers ;  still  others  became  firmly  attached,  and 
remained  firm  for  a  year  or  two,  when  they  became  loose  from  resorption 
of  their  roots,  and  on  account  of  intense  irritation  had  to  be  extracted ; 
while  a  very  limited  number  have  done  good  service  for  periods  ranging 
from  three  to  ten  years.  On  the  whole,  then,  the  operation  is  not  one  to 
be  recommended  except  under  the  most  favorable  circumstances, — viz., 
when  a  freshly  extracted  healthy  tooth  can  be  inserted  into  the  newly 
formed  alveolus  of  a  youth  or  young  adult  of  the  most  perfect  health  and 
constitution. 


CHAPTER    XXXII. 

DISLOCATION   OF   THE   TEETH. 

Definition. — Dislocation,  from  the  Latin  dislocatus,  to  put  out  of 
place  ;  luxation,  from  the  Latin  luxatus,  to  put  out  of  joint.  A  dislocation 
or  luxation  is  a  displacement  of  a  part  from  its  normal  situation. 

Two  or  more  bones  whose  articular  surfaces  have  lost,  wholly  or  in  part, 
their  natural  relationship  are  said  to  be  dislocated  or  luxated,  and  the 
condition  would  be  termed  a  dislocation  or  luxation. 

A  tooth  which  is  partially  or  completely  dislodged  from  its  alveolus  is 
said  to  be  dislocated  or  luxated. 

Dislocations  of  the  teeth  are  of  two  classes, — viz.,  partial  and  complete. 

A  partial  dislocation  is  one  in  which  the  tooth  is  loosened  and  i^artially 
dislodged  from  its  normal  attachments  and  position. 

A  complete  dislocation  is  one  in  which  the  tooth  is  .completely  or  wholly 
dislodged  from  its  normal  attachment  and  position. 

Dislocations  of  the  teeth  are  always  the  result  of  some  form  of  external 
violence,  such  as  direct  blows  or  falls  upon  the  teeth,  accidental  dislodge- 
ment  of  a  contiguous  tooth  in  the  operation  of  extraction,  or  violence  ap- 
I)lied  indirectly,  as  a  blow  or  fall  upon  the  chin  or  the  side  of  the  face. 
Injuries  which  cause  fractures  of  the  jaws  almost  invariably  produce  dis- 
location of  one  or  more  teeth  at  the  line  of  the  fracture. 

In  partial  dislocations  the  tooth  may  be  either  dislodged  in  an  outward 
direction  or  driven  into  the  alveolus  to  a  greater  or  less  extent,  while  in 
comijlete  dislocations  the  tooth  may  be  entirely  dislodged  outwardly,  or 
completely  driven  through  the  alveolus  into  the  nose  or  the  antrum  of  High- 
more. 

Treatment. — In  the  treatment  of  partial  outward  dislocations  of  the 
teeth  the  parts  should  be  thoroughly  irrigated  with  antiseptic  solutions, 
cleansed  from  all  blood-clots  and  foreign  substances  or  loose  pieces  of  frac- 
tured alveolar  process,  the  teeth  forced  back  into  their  normal  position 
and  supported  by  ligatures  of  silk  or  wire,  or  firmly  held  in  place  with  a 
vulcanite  or  metal  splint  cemented  to  the  adjoining  teeth,  and  allowed  to 
remain  until  union  with  the  alveolar  tissues  has  taken  place.  This  result 
may  be  confidently  expected  in  from  one  week  to  ten  days,  provided  sup- 
puration does  not  supervene.  To  guard  against  the  establishment  of 
suppuration  the  mouth  and  the  injured  parts  should  be  frequently  irrigated 
with  antiseptic  solutions. 

In  the  treatment  of  those  cases  in  which  the  tooth  is  partially  driven 
through  the  alveolus,  the  crown  of  the  tooth  should  be  grasped  by  a  pair 
of  suitable  forceps  and  drawn  down  to  its  normal  position.  In  a  majority 
of  these  cases,  however,  it  will  be  found  that  the  attachment  of  the  tooth 
to  the  alveolar  wails  has  been  entirely  broken  up,  so  that  when  force  is 
applied  to  draw  the  tooth  into  position  it  will  be  completely  dislocated. 

501 


602  OPEKATIVE   DENTISTRY. 

If  the  tootli  still  retains  a  partial  attacliment  to  tlie  alveolus,  it  should  be 
treated  as  just  described,  and  held  in  position  by  means  of  a  ligature  or  a 
splint. 

As  a  rule,  teeth  which  have  been  dislocated  even  partially  have  suffered 
rupture  of  the  nerve  and  blood-vessels  at  the  apical  foramen,  so  that  in  a 
short  time,  ranging  from  ten  days  to  a  few  weeks,  the  tooth  gives  evidences 
of  containing  a  devitalized  pulp,  and  should  therefore  be  opened,  the  pulp 
extirj^ated,  and  the  pulp-canal  filled. 

Occasionally,  however,  if  the  tooth  is  immediately  replaced  in  its 
normal  position,  union  of  the  blood-vessels  and  the  nerve  may  take  place. 
I^umerous  cases  of  this  character  have  been  reported  from  time  to  time  in 
dental  text-books  and  periodical  literature.  The  writer  has  had  two  such 
cases  in  his  own  practice, — one  a  lower  second  bicuspid,  which  responded 
to  the  usual  tests  of  heat,  cold,  and  the  electric  current  twelve  years  after- 
wards, and  the  other  a  second  lower  molar,  which  was  vital  two  years 
afterwards.  These  cases  were  both  of  them  in  young  women  of  vigorous 
health  and  good  family  history.  These  results  are  more  likely  to  follow 
such  accidents  occurring  in  the  young,  particularly  if  they  happen  during 
the  formative  period  of  the  teeth,  than  if  they  occur  at  any  time  there- 
after. In  tubercular  and  syphilitic  individuals  replantation  of  dislocated 
teeth  is  rarely  successful,  as  injuries  of  even  a  trivial  nature  are  prone  to 
inflammation  and  suppuration. 

Teeth  which  have  been  completely  dislocated  outwardly  should,  before 
being  replanted,  have  the  pulp  extirpated  and  the  pulp-canal  filled  with 
gutta-percha,  and  the  apical  foramen  and  the  crown-cavity  filled  with  gold. 
These  operations  should  be  performed  under  the  strictest  antiseptic  pre- 
cautions, as  suggested  in  the  section  of  the  chapter  on  Dento- Alveolar 
Abscess  devoted  to  replantation  of  the  teeth. 

Injuries  which  cause  dislocations  by  driving  the  teeth  into  or  through 
their  alveoli  and  into  the  nasal  cavity  or  the  antrum  of  Highmore  usually 
cause  more  or  less  severe  fracture  and  comminution  of  the  alveolar  process 
and  superior  maxillary  bones.  Such  injuries  are  generally  the  result  of 
falls  from  a  considerable  height,  as  from  a  building,  or  being  thrown  from 
a  horse  or  a  bicycle,  or  from  some  crushing  injury  like  railway  accidents, 
the  overturning  of  a  carriage  upon  the  occuiDant,  or  an  elevator  accident 
whereby  the  head  is  caught  between  the  moving  car  and  the  floor.  But 
even  under  such  circumstances  it  is  possible  in  many  cases  to  bring  the 
fractured  bones  into  normal  apposition  and  to  successfully  replant  the 
teeth. ^  It  is  surprising  how  readily  reunion  will  take  place  in  these  cases, 
and  what  good  cosmetic  results  may  be  obtained  by  the  aj^plication  of  a 
little  skill  and  patient,  intelligent,  after-treatment. 

The  first  thing  to  be  done  in  these  cases  after  the  mouth  has  been 
cleansed  of  blood- clots  and  rendered  as  nearly  aseptic  as  the  circumstances 
will  permit,  by  the  liberal  use  of  antiseptic  solutions,  is  to  search  for  and 
remove  all  of  those  teeth  which  have  been  driven  into  their  alveoli  or  into 
the  nasal  cavity  or  the  maxillary  sinus.    In  nearly  all  of  these  cases  it  will 

*  Marshall's  Injuries  and  Surgical  Diseases  of  the  Face,  Mouth,  and  Jaws,  1897. 


DISLOCATION    OF    THE    TEETH, 


503 


be  found  that  the  alveolar  process  is  split  open,  the  external  plate  of.  the 
process  being  the  one  which  is  usually  fractured  and  forced  outward. 

This  condition  very  materially  assists  in  the  effort  to  find  and  remove 
the  buried  teeth.  The  teeth  so  dislocated  are  often  completely  buried  out 
of  sight,  or  are  lost  in  the 
antrum.  Diligent  search  must 
be  made  for  all  missins:  teeth  : 


Fig.  583. 


and   if  one  has  been   driven 

into     the     antrum,     this    sinus  Torsion  forceps. 

must  be  opened  by  enlarging 

the  alveolus  of  the  tooth,  and  the  tooth  removed.  This  is  sometimes  a 
difficult  problem  ;  but  if  the  opening  be  made  sufficiently  large,  the  tooth 
can  be  grasped  by  a  pair  of  torsion  forceps  (Fig.  583),  or  bullet  forceps 
(Fig.  584),  and  removed ;  if  the  forceps  will  not  retain  their  grasp  upon 
the  tooth,  it  is  possible  to  remove  it  with  a  wire-loop  snare  (Fig.  585)  or 
an  ecraseur  such  as  is  used  for  the  removal  of  nasal  polypi. 

After  the  completely  dislocated  teeth   have  been  extracted,  all  loose 

fragments  of  bone  should  be  re- 
FiG.  584.  moved  from  between  the  alveolar 

plates    and   the   bones  brought 
into  correct  apposition. 

In   order  to   retain  them  in 

their  normal  position  it  may  be 

necessary  to  pass  silver  sutures 

through  the  alveolar  plates  by 

first  drilling  holes  for  their  reception  at  suitable  locations.     Lead  buttons 

may  be  used  at  the  termini  of  the  sutures  to  keep  them  from  cutting  into 

the  soft  tissues. 

After  the  fractured  bones  have  been  adjusted  the  alveoli  should  be 
cleansed  from  blood- clots,  and  the  teeth,  which  had  been  previously 
cleansed  and  placed  in  a  tepid  three  per  cent,  solution  of  carbolic  acid  or  a 

Fig.  585. 


Bullet  forceps. 


Qooeh's  double  canula  snare. 


1  to  1000  bichloride  solution,  may  now  be  replanted  in  their  normal  position 
and  retained  by  means  of  ligatures. 

The  first  part  of  the  operation  would  of  necessity  be  of  such  a  painful 
nature  that  a  general  anaesthetic  would  be  required,  and  the  length  of  time 
that  would  be  necessary  to  remove  the  pulps  from  the  teeth  and  properly 
fill  them  would  make  it  impossible  to  do  this  while  the  patient  was  under 
the  anaesthetic.     While,  upon  the  other  hand,  the  chances  of  reunion  of 


504  OPERATIVE    DENTISTRY. 

the  replanted  teeth  with  their  alveoli  is  much  greater  if  the  teeth  are 
replaced  within  an  hour  or  two  after  the  injury  which  has  dislocated  them. 
The  pulp -canals  of  such  teeth  may  be  opened  later,  and  such  treatment 
instituted  as  the  conditions  indicate. 

''It  is  interesting  in  this  connection  to  note  the  time  required  to 
produce  death  in  the  various  tissues  of  the  body  by  the  arrestation  of  the 
blood-current.  The  period  varies  in  the  different  tissues.  Brain-tissue, 
renal  epithelium,  and  intestinal  epithelium  die  in  two  hours.  Skin,  bone, 
and  connective  tissue  continue  to  live  over  twelve  hours."  (Cohnheim.) 
Tissues  which  exercise  special  functions  die  more  quickly  than  those  which 
do  not  exercise  such  functions.  These  facts  should  govern  all  operations 
for  the  transplantation  or  replantation  of  teeth.  Success  is  more  likely  to 
follow  the  effort  of  transplanting  and  replanting  of  teeth  if  the  operation 
is  completed  within  an  hour  or  two  after  the  extraction  of  the  tooth.* 

Sometimes  a  single  anterior  tooth  will  be  driven  through  its  alveolus 
and  into  the  cancellated  tissues  beyond,  penetrating  the  floor  of  the  nasal 
cavity,  without  fracturing  the  alveolar  process.  Under  such  circumstances 
the  tooth  will  be  so  firmly  fixed  as  to  require  considerable  force  to  dis- 
lodge it.  The  writer  saw  a  case  of  this  character  at  one  time  in  which  a 
central  incisor  was  driven  completely  out  of  sight,  and  the  tooth  was  sup- 
posed by  the  patient  to  have  been  knocked  out  and  lost.  The  case  was  so 
diagnosed,  also,  by  the  family  physician  and  the  dentist.  Careful  examina- 
tion with  the  probe,  however,  discovered  the  crown  of  the  tooth  about  a 
third  of  an  inch  beyond  the  border  of  the  alveolus,  which  was,  after  con- 
siderable difficulty,  extracted  with  a  pair  of  very  thin-beaked,  straight 
root-forceps.  The  tooth,  after  the  removal  of  the  pulp  and  appropriately 
filling  the  canal,  apical  foramen,  and  crown-cavity,  was  replanted  and 
made  a  good  union. 

Prognosis. — The  prognosis  of  replanted  teeth  under  the  conditions 
just  mentioned  is  exceptionally  good  in  all  healthy  subjects.  The  period 
of  the  future  usefulness  of  such  teeth  may  be  confidently  expected  to  ex- 
tend over  many  years.  In  some  of  them,  however,  there  is,  after  a  vary- 
ing period,  a  tendency  to  resorption  of  the  root,  and  ultimate  loss  of  the 
tooth. 

*  Marshall,  Injuries  and  Surgical  Diseases  of  the  Face,  Mouth,  and  Jaws,  p.  98. 


CHAPTER   XXXIII. 

FRACTUKES   OF   THE   TEETH. 

Definition. — Fracture  (from  the  Latin /racfjtra,  a  break),  the  breaking 
of  a  bone  or  a  tooth,  eitlier  by  external  violence  or  other  form  of  injury. 

Fractures  of  the  teeth,  like  fractures  of  the  bones,  may  be  divided  into 
three  classes, — ^viz.,  simple,  comjDound,  and  comminuted. 

Simple  fractures  are  those  which  involve  the  hard  structures  of  the 
crown  and  do  not  injure  the  puli?. 

Compound  fractui^es  are  those  in  which  the  fracture  is  of  such  extent 
as  to  involve  the  j)ulx)  in  any  portion  of  the  crown  or  root. 

Comminuted  fractures  are  those  in  which  the  tooth  is  broken,  crushed, 
or  si3lit  into  many  fragments. 

Simple  fractures  may  be  of  such  a  nature  as  to  involve  only  a  very 
small  portion  of  the  enamel,  or  they  may  be  so  extensive  as  to  involve  a 
large  section  of  the  crown  and  nearly  expose  the  pulp. 

The  incisors,  from  their  exposed  position,  are  more  liable  to  fractures 
of  all  classes  than  the  bicuspids  or  the  molars,  while  the  cuspids,  from 
their  peculiar  form  and  great  strength,  are  the  least  liable  to  such  acci- 
dents, though  they  are  by  no  means  entirely  exempt. 

The  causes  which  produce  simple  fractures  of  the  anterior  teeth  are 
grinding  the  teeth  and  incising  such  substances  as  threads,  which  chip  the 
edges  of  the  enamel,  or  blows  and  falls,  which  cause  fractures  of  larger 
portions  of  enamel  and  dentin,  while  such  fractures  occurring  in  the 
bicuspids  and  molars  are  usually  produced  by  biting  hard  substances  or 
by  blows  and  falls  upon  the  chin,  which  drive  the  jaws  together  and  split 
off  a  cusp  or  produce  more  serious  injury. 

Slight  fractures  confined  to  the  enamel  need  only  to  be  made  smooth 
with  files,  stones,  or  disks,  and  then  polished  with  pumice.  When  larger 
sections  of  the  crown  are  broken  away,  the  lost  portions  should  be  restored 
with  gold  or  porcelain.  It  must  not  be  forgotten,  however,  that  injuries 
which  expose  the  dentin  often  leave  this  portion  of  the  tooth  extremely 
sensitive,  and  not  infrequently  cause  hypersemia  and  death  of  the  pulj)  as 
a  result  of  the  shock  induced  by  the  injury,  or  from  thermal  impressions 
upon  the  exposed  fibrillfe. 

The  application  of  escharotics  to  the  exposed  dentin  for  the  purpose 
of  obtunding  its  hyx^ersensitiveness  is  to  be  deprecated,  for  the  reason  that 
such  applications  often  cause  severe  irritation  and  hypersemia  of  the  piilp, 
which  may  result  in  devitalization.  For  these  reasons  it  is  better  to  treat 
such  cases  by  covering  the  exposed  dentin  with  gutta-percha  or  zinc  oxy- 
phosphate  cement  and  wait  for  developments.  If  after  a  month  or  six 
weeks  the  tooth  remains  vital  and  is  not  hypersensitive  to  thermal 
changes,  a  permanent  restoration  of  the  lost  portion  with  gold  or  porcelain 
may  be  undertaken, 

505 


508  OPERATIVE   DENTISTEY. 

Compound  fractures  are  generally  the  result  of  severe  injuries,  such  as 
blows  or  Mis,  which  bring  the  anterior  teeth  in  contact  with  some  hard 
substance,  causing  fracture  of  the  crown  and  exposing  the  pulp,  or  which 
drives  the  jaws  forcibly  together  and  splits  the  crown  of  a  bicuspid  or  a 
molar  through  the  pulp-chamber,  or  carries  away  a  large  section  of  the 
crown,  exposing  the  pulp.  The  fragments  in  fractures  which  occur  through 
the  pulp-chamber,  sometimes  in  such  close  apposition  that  the  most  careful 
examination  is  necessary  to  detect  the  character  of  the  injury.  The  writer 
has  seen  several  cases  in  which  a  persistent  odontalgia  was  finally  discov- 
ered to  be  due  to  such  a  cause. 

Bicuspids  and  molars  which  have  been  filled  upon  the  mesio-disto- 
morsal  surfaces  are  quite  prone  to  be  fractured  through  the  pulp-chamber 
or  to  have  a  cusx3  split  off  while  chewing  very  hard  food,  or  when  acci- 
dentally biting  upon  some  foreign  substance  hidden  in  the  food,  like  a 
piece  of  bone,  a  shot,  a  piece  of  shell  or  stone. 

Compound  fractures  of  the  anterior  teeth  are  usually  either  transverse 
or  oblique,  while  in  the  bicuspids  and  molars  the  line  of  fracture  is  gen- 
erally oblique  or  longitudinal,  following  the  line  of  the  pulp-chamber. 

Oblique  fractures  are,  however,  the  most  common  in  both  the  bicuspids 
and  molars.  In  bicuspids  which  have  two  roots,  and  in  the  lower  molars, 
the  fracture  in  the  crown  may  extend  in  a  longitudinal  direction,  separa- 
ting the  roots,  while  in  the  superior  molars  it  usually  separates  the  palatine 
from  the  buccal  roots.  Occasionally  the  root  of  an  anterior  tooth  may  be 
fractured  transversely  at  some  distance  beneath  the  gum. 

Treatment. — Fractures,  either  oblique  or  transverse,  which  open  the 
pulp-chamber,  but  do  not  extend  beneath  the  gum,  should  be  treated  with 
a  view  to  finally  setting  an  artificial  crown  upon  the  remaining  firm  root, 
but  in  those  cases  in  which  the  fracture  follows  the  pulp-canal,  or  in  which 
the  root  is  otherwise  seriously  involved,  extraction  is  the  only  treatment  to 
be  recommended. 

An  exposed  pulp  should  be  extirpated  at  once  in  order  to  give  relief 
from  the  severe  pain.     This  should  be  done  under  a  general  ansesthetic. 

In  devitalized  superior  molars  and  in  double-rooted  superior  bicuspids 
which  have  been  fractured  on  a  line  with  the  pulp -chamber  separating  the 
roots  it  is  sometimes  possible,  after  ligating  the  fragments  together  with  a 
stout  silk  ligature,  to  secure  the  fractured  parts  and  retain  them  in  a  nor- 
mal position  by  drilling  a  hole  through  the  crown  bucco-lingually,  well 
towards  the  gum,  counter-sinking  the  hole  upon  both  the  buccal  and  lin- 
gual surfaces  and  inserting  a  bolt  with  a  screw-nut  made  of  eighteen-carat 
gold,  filling  over  the  head  of  the  bolt  and  the  nut  with  gold  or  with  zinc 
oxyphosphate  or  amalgam,  and  replacing  any  fillings  in  the  line  of  the 
fracture  through  the  crown  with  cement  or  amalgam,  and  in  very  rare 
instances  with  gold. 

Another  method  is  to  fit  a  gold  or  platinum  band  to  the  outer  circum- 
ference of  the  tooth,  and  retain  it  in  position  with  zinc  oxyphosphate. 
This  method  is  particularly  applicable  to  the  lower  molars  which  have  been 
so  fractured  as  to  separate  the  mesial  and  distal  roots. 

Still  another  method  may  sometimes  be  adopted  with  success  in  those 


FRACTURES  OF  THE   TEETH.  607 

cases  in  whicli  the  crown  is  considerably  decayed  or  contains  large  fillings, 
— viz.,  to  set  a  gold  shell -crown.  This  may  be  accomplished  by  first  se- 
curing the  fragments  in  proper  apposition  by  the  aid  of  a  piece  of  fine  iron 
binding  wire  passed  around  the  cervix  of  the  tooth  and  twisted  tightly. 
The  crown  may  then  be  cut  to  proper  shape  and  length,  measured,  the 
band  fitted,  and  the  crown  made  and  finished  by  the  usual  methods. 

Comminuted  fractures  are  always  the  result  of  severe  injury  from  con- 
cussion or  some  heavy  crushing  force,  which  usually  so  comminutes  the 
crown  and  root,  together  with  the  alveolar  walls,  as  to  destroy  the  integ- 
rity of  the  tooth  and  make  it  necessary  to  remove  the  crushed  fragments. 
Occasionally  the  crown  only  will  be  comminuted  and  the  root  left  intact. 
Under  such  circumstances  the  root  may  be  conserved  and  an  artificial 
crown  set  upon  it. 

Spontaneous  fracture  sometimes  occurs  in  a  tooth  which  contains  a  de- 
vitalized pulp  or  a  very  large  metal  filling  without  any  seemingly  apparent 
cause.  It  has  been  suggested  by  some  writers  that  in  the  former  the  tooth 
was  fractured  by  internal  pressure  from  the  evolution  of  gas  in  a  closed 
pulp-cavity  as  the  result  of  the  decomposition  of  the  pulp  ;  while  in  the 
latter  it  was  due  to  the  expansion  of  the  metal  filling  induced  by  thermal 
changes.  Tomes  suggests  that  it  may  be  due  sometimes  to  a  calcified  pulp, 
which  acts  as  an  internal  wedge  when  a  distorting  force  is  brought  to  bear 
upon  the  tooth.  It  is  possible  that  such  forces  as  have  been  mentioned 
may  produce  these  fractures,  but  the  writer  is  inclined  to  the  opinion  that 
in  each  of  these  conditions  the  fracture  is  often  due  to  some  unusual  force 
applied  to  the  tooth,  either  in  masticating  or  in  grinding  the  teeth  together 
while  the  individual  is  asleep.  A  tooth  with  a  devitalized  pulp  has  usu- 
ally been  weakened  by  a  cavity  of  decay,  while  a  tooth  which  contains  a 
large  metal  filling  is  also  in  a  weakened  condition,  and  therefore  less  able 
to  withstand  any  undue  strain  that  might  be  placed  upon  it. 

Union  of  Fractured  Teeth. — As  a  rule,  teeth  which  have  been  frac- 
tured do  not  become  reunited.  This  is  no  doubt  due  to  the  fact  that  the 
dentin  has  no  blood  circulation,  and  that  the  cementum  has  but  few  blood- 
vessels as  compared  with  bone-tissue,  and  yet  there  are  several  instances 
on  record  in  which  union  of  fractured  teeth  has  undoubtedly  taken  place. 
Fractured  bones  almost  universally  reunite,  and  but  for  the  character  of 
the  dental  tissues  the  same  result  might  be  confidently  expected  in  the 
teeth.  The  union  which  has  taken  place  in  the  few  instances  recorded 
seems  to  be  due  to  the  active  agency  of  the  pericementum,  which  has 
thrown  out  new  osseous  (cement)  material  around  the  fracture,  just  as  is 
done  by  the  periosteum  in  fractured  bones.  It  is  possible  that  the  pulp 
in  some  rare  instances  may  take  part  in  forming  the  reunion.  Eeunion  of 
fractured  teeth  is  much  more  likely  to  result  if  the  fracture  takes  place 
during  the  formative  period  of  the  root,  or  soon  thereafter,  than  it  is  if  the 
fracture  occurs  after  adult  life  is  reached.  The  probability  of  reunion 
taking  place  in  a  fractured  tooth  is  increasingly  greater  as  the  line  of 
fracture  nears  the  apical  third  of  the  root. 

The  conditions  which  are  necessary  to  promote  reunion  in  the  fractured 
root  of  a  tooth  are  correct  apposition  and  immobility  of  the  fractured 


508  OPERATIVE   DENTISTRY. 

parts,  the  vitality  of  the  pulp,  and  a  healthy  condition  of  the  pericemen- 
tum. Eeunion  will  fail  if  the  fractured  parts  are  separated  by  any  appre- 
ciable space,  or  if  they  are  in  constant  motion,  or  the  pulp  dies  and  be- 
comes decomposed,  as  septic  conditions  are  established  at  the  site  of  the 
injury,  and  by  that  means  the  reparative  process  is  arrested  or  entirely 
prevented,  and  if  the  pericementum  is  not  in  a  fairly  healthy  condition 
the  reparative  process  cannot  be  established,  as  this  is  the  most  important 
structure  involved  in  this  process. 

Wedl  *  is  of  the  opinion  that  the  pulp  takes  some  part  in  the  process  of 
reunion  of  fractured  teeth,  and  he  figures  two  reunited  fragments  in  which 
a  deposition  of  reparative  dentin  took  place, — one  was  a  human  superior  bi- 
cuspid, the  other  an  incisor  of  an  antelope.  Tomes f  mentions  two  cases,  one 
a  human  molar  in  which  union  of  the  fragments  had  been  secured  by  the 
formation  of  new  cement-tissue  around  the  fracture.  The  other  was  a  tusk 
of  a  hii)popotamus  in  which  the  fragments  had  been  considerably  sepa- 
rated, but  which  had  been  perfectly  reunited  with  new-formed  cementum. 

Professor  Owen  mentions  a  similar  case  in  the  tusk  of  a  hippopot- 
amus. X 

Hyatt  describes  a  specimen  of  reunited  fracture  of  a  central  incisor  to 
be  found  in  the  Anatomical  Museum  of  Breslau. 

Heider  mentions  a  specimen  contained  in  his  private  collection  of  a 
perfectly  reunited  fracture  in  a  superior  bicusiDid. 

Hohl  records  fourteen  cases  found  in  man  and  the  lower  animals,  eight 
of  which  were  human,  seven  being  incisors  and  one  a  superior  bicuspid. 
One  remarkable  case  recorded  by  Hohl  in  which  reunion  was  perfect  is 
described  as  follows  : 

''  Professor  Y.,  as  he  was  about  entering  a  railway  car,  fell,  striking  his 
mouth  upon  the  sharp  edge  of  an  iron  step  in  such  a  way  that  the  right 
superior  central  incisor  was  fractured  lengthwise.  The  fracture  separated 
the  tooth  in  the  middle  of  the  crown  so  completely  that  the  two  fragments 
diverged  from  each  other,  and  could  be  moved  back  and  forth.  After  the 
lapse  of  fourteen  days,  during  which  time  the  intense  pain  entirely  pre- 
vented the  use  of  the  fractured  tooth,  a  more  comfortable  condition  en- 
sued, and  in  a  few  weeks  more  the  tooth  completely  resumed  its  normal 
functions.  The  two  halves  of  the  tooth  became  firmly  adherent  to  one 
another,  and  the  line  of  union  was  indicated  by  merely  a  fine  line  with  a 
slightly  brownish  tinge."  § 

The  late  Sir  E.  Saunders  has  described  an  incisor  belonging  to  his 
private  collection,  which  shows  a  perfectly  reunited  fracture  which  had 
occurred  at  the  junction  of  the  middle  and  apical  thirds  of  the  root. 
Belisario  also  reports  a  case  of  fracture  of  a  tooth  with  reunion  of  the 
severed  fragments.  Bennett  describes  a  fractured  incisor  tooth  in  which 
the  fragments  were  apparently  considerably  displaced  and  had  become 
reunited  in  their  displaced  position. 

*  Wedl's  Dental  Pathology.  f  Tomes' s  Dental  Surgery. 

t  Odontography.  §  American  System  of  Dentistry. 


CHAPTER    XXXIY. 

RESORPTION   OF   THE   ROOTS   OF   PERMANENT   TEETH. 

Definition. — Resorption  (Latin,  resorptio,  from  re,  again,  and  sohere,  to 
absorb),  the  process  wliereby  formed  tissue  is  converted  into  its  original 
elements  by  the  action  of  specialized  cells  and  taken  into  the  blood-cur- 
rent by  absorption. 

Bone  is  resorbed  through  the  action  of  the  osteoclast  cells.  The  roots 
of  the  permanent  teeth  are  resorbed  by  a  similar  process,  and  is  analogous 
to  that  observed  to  take  place  in  the  roots  of  the  deciduous  teeth  prior  to 
their  exuviation.  The  former,  however,  is  a  pathologic  condition,  while 
the  latter  is  physiologic. 

The  resorption  of  dental  tissues  other  than  that  appearing  in  connec- 
tion with  the  removal  of  the  roots  of  the  deciduous  teeth  prior  to  the 
eruption  of  the  permanent  teeth  must  therefore  be  considered  a  pathologic 
process. 

Causes. — T\iq  principal  predisposing  causes  of  resorption  of  the  roots  of 
the  permanent  teeth  are  of  two  classes, — one  which  is  dependent  upon  con- 
ditions associated  with  the  tooth  itself,  and  the  other  to  conditions  which 
are  entirely  foreign  to  the  tooth. 

In  the  first  class  of  causes  are  death  of  the  pulj),  necrosis  of  portions 
of  the  pericementum,  and  functional  disuse  of  the  tooth  due  to  the  loss  of 
its  antagonist.  In  the  second  class  are  irritation  from  an  erupting  but 
malposed  tooth,  as,  for  instance,  a  third  molar,  which  presses  against  the 
distal  root  of  a  second  molar,  or  the  presence  of  a  foreign  body  in  con- 
tact with  the  root. 

The  process  of  resorption  is  much  more  rapid  in  pulpless  teeth  and  in 
those  in  which  portions  of  the  pericementum  have  been  destroyed  by  a 
suppurative  inflammation,  such  as  would  attend  dento-alveolar  abscess. 
It  may  be  stated  as  a  general  fact  that  the  progress  of  the  disease  is  much 
more  rapid  in  tissues  whose  blood-supply  or  nutrition  have  been  reduced 
or  largely  cut  off,  while,  on  the  other  hand,  the  greater  the  blood- supply 
coming  to  the  part  so  attacked  the  more  successfully  will  it  resist  the  de- 
structive process.  In  other  words,  vital  resistance  plays  an  important 
part  in  determining  the  rapidity  with  which  the  tissues  are  dissolved  by 
this  process. 

When  the  process  attacks  a  tooth  with  a  vital  pulp,  its  action  is  more  and 
more  retarded  as  it  approaches  the  pulp,  and  in  some  of  these  cases  the 
cementum  and  dentin  have  been  removed,  leaving  only  a  thin  tube-like  pro- 
tection of  dentin  surrounding  the  pulp.  In  those  cases  of  resorption  caused 
by  an  advancing  malposed  tooth,  it  will  be  noticed  that  at  the  point  of  con- 
tact only  will  the  i)rocess  be  active,  and  the  form  of  the  excavation  made 
in  the  root  of  the  tooth  attacked  by  the  resorptive  process  will  correspond 
to  that  portion  of  the  surface  of  the  tooth  which  is  advancing  towards  it. 

509 


510  OPERATIVE   DENTISTRY. 

There  is  never,  however,  absolute  contact  of  these  surfaces ;  they  are 
always  separated  by  a  mass  of  multinucleated  cells  which  are  doubtless 
modified  osteoclasts.  The  process  of  resorption  sometimes  extends  to 
such  depth  as  to  expose  the  pulp  in  the  root  of  the  tooth,  and  thus  cause  a 
severe  and  sometimes  obscure  odontalgia  and  later  on  a  dento-alveolar 
abscess. 

Exciting  Causes. — Continued  irritation  of  almost  any  form  may  in- 
augurate the  resorptive  process.  Among  the  more  common  of  the  exciting 
causes  may  be  mentioned  chronic  septic  pericementitis,  chronic  dento- 
alveolar  abscess,  a  nerve  broach  broken  olf  in  the  pulp-canal  and  project- 
ing through  the  apical  foramen,  the  presence  of  a  root-canal  filling  which 
projects  into  the  apical  space,  or  a  severe  injury,  as  from  a  blow  upon  the 
tooth.  In  certain  cases,  however,  the  resorptive  process  seems  to  have  no 
discoverable  cause  whatever. 

Pathology. — The  macroscopic  appearances  of  the  roots  of  teeth  which, 
are  being  resorbed  present  such  a  wide  difference  that  it  may  be  safely  said 
that  the  process  rarely  attacks  any  two  teeth  alike.  This  will  be  noticed 
by  reference  to  the  illustrations.  Fig.  586  shows  the  result  of  a  chronic 
irritation  at  the  apex  of  a  vital  superior  central  incisor.  In  this  case  tbe 
resorption  has  produced  a  smooth,  regular,  and  rounded  shortening  of  the 
root.  Fig.  587  illustrates  the  same  condition  occurring  at  the  apices  of 
roots  of  a  devitalized  superior  molar.  Fig.  588  represents  two  vital  superior 
central  incisors  in  which  the  process  of  absorption  was  most  active  upon  the 
mesial  surface,  extending  from  apex  to  cervix.  The  writer  is  indebted  to 
Dr.  Wright,  of  Chicago,  for  these  latter  specimens  loaned  from  his  private 
collection.  The  surfaces  which  have  been  attacked  in  these  teeth,  present 
deep,  uneven,  bay-like  excavations  and  numerous  small,  rounded  open- 
ings, which  give  them  the  appearance  of  being  worm-eaten.  In  Fig.  589 
the  process  is  shown  to  have  scooped  a  large,  smooth  excavation  in  a 
devitalized  superior  bicusj)id,  well  up  towards  the  apex,  leaving  sharp, 
clean-cut  edges.  Sometimes  the  whole  root  is  absorbed,  but  this  is  rare. 
Fig.  590  shows  a  devitalized  inferior  bicusi)id  in  which  the  disease  has 
extended  much  farther.  This  tooth  had  been  crowned  with  gold  several 
years  before  the  writer  saw  the  case,  and  no  other  history  could  be  ob- 
tained. In  this  case  the  resorptive  process  had  extended  into  the  crown 
upon  one  side.  Fig.  591,  a  devitalized  central  incisor,  has  lost  about  one- 
half  of  its  root ;  the  disease  evidently  began  on  the  labial  aspect  of  the 
root  near  the  apex.  In  this  case  the  dentin  has  been  dissolved  much  more 
readily  than  the  cementum,  thus  causing  a  very  deep  depression. 

Fig.  592  shows  a  devitalized  superior  central  incisor  in  which  the  process 
of  resorption  has  gone  considerably  farther,  and  has  removed  almost  the 
entire  root  and  formed  a  deep  dei^ression  in  the  crown. 

Fig.  593  was  a  vital  superior  cuspid  which,  has  a  small  depression  or 
cup-shaped  cavity  upon  the  labial  surface  of  the  root  near  the  middle,  and 
shows  a  very  early  stage  in  the  resorptive  process. 

Fig.  594  was  another  vital  superior  cuspid  in  which  the  disease  began 
at  tlie  apex  and  has  destroyed  the  upper  half  of  the  root.  The  peculiarity 
of  this  case  lies  in  the  fact  that  the  disease  has  hollowed  out  the  root 


Fig.  586. 


Fig.  .587. 


Fig.  588. 


Fig.  589. 


Fig.  591. 


Fig.  592. 


□ 


Fig.  596. 


Fig.  593. 


Fig.  594. 


Fig.  595. 


Fig.  597. — Osteoclasts,  producing  resorption  of  the  root  of  a  tooth.     X  45. 


Tig.  598. — Osteoclasts,  producing  resorption  of  the  root  of  a  tooth. 


RESORPTION    OF    THE    ROOTS    OF    PERMANENT   TEETH.  511 

almost  to  tlie  cervix,  leaving  the  outer  shell  of  the  cementiim  intact,  and 
preserving  a  thin  tube  of  dentin  around  the  pulp. 

Fig.  595  represents  the  most  interesting  case  of  all.  This  is  a  lower  sec- 
ond molar,  which  had  been  extracted  and  replanted  by  a  colleague  for  the 
cure  of  pyorrhoea  alveolaris.  The  tooth  was  supported  in  position  by  a  gold 
splint  which  encircled  this  tooth,  the  first  molar,  and  the  second  bicuspid. 
The  operation  was  made  about  two  years  previously.  The  tooth  had  been 
troublesome  for  more  than  a  year,  but,  as  there  was  no  discharge  of  pus, 
it  was  thought  best  to  allow  it  to  remain.  It  finally  caused  irritation  of 
the  gum,  and  was  therefore  extracted.  In  this  case  the  root  and  a  large 
part  of  the  dentin  of  the  crown  was  entirely  resorbed.  The  tissue,  how- 
ever, was  not  removed  in  the  same  manner  as  in  the  resorption  of  the 
deciduous  teeth,  for  in  them  the  surface  is  left  comparatively  smooth, 
while  in  this  case  it  is  full  of  deep  depressions  and  perforated  with  holes, 
as  though  worm-eaten. 

Fig.  596  shows  a  very  peculiar  form  of  resorption  in  a  superior  second 
molar,  the  result  of  inflammation  of  the  pericementum  induced  by  drilling 
through  the  side  of  the  root  in  an  effort  to  open  the  pulp- canal  in  the  disto- 
buccal  root.  The  probes  are  passed  through  the  cavity  of  decay  and  the 
Oldening  in  the  root  made  by  the  drill  and  through  two  other  openings 
which  were  the  result  of  the  action  of  the  cementoclasts. 

Upon  microscopic  examination  of  the  surface  which  is  being  resorbed  it 
is  found  to  be  covered  with  cu]3-shaped  depressions  of  great  minuteness, 
but  there  ai^pears  to  be  no  alteration  in  the  size  or  of  the  arrangement  of 
the  dentinal  tubuli.  These  minute  depressions  are  Howship's  lacunse,  and 
are  doubtless  formed  by  the  action  of  multinucleated  cells  (Figs.  597  and 
598),  the  osteoclasts,  or  odontoclasts. 

The  modus  operandi  by  which  the  roots  of  the  permanent  teeth  are  re- 
sorbed seems  to  be  identical  with  the  process  by  which  foreign  substances 
composed  of  animal  tissue,  like  ivory,  catgut,  silkworm  gut,  silk-ligatures, 
sponge,  and  decalcified  chicken-bone  drainage-tubes,  etc.,  are  resorbed 
when  buried  in  the  living  animal  tissues.  The  success  of  the  process 
seems  to  depend  upon  the  character  of  the  inflammation,  which  must  be 
of  a  degree  that  falls  short  of  the  suxjpurative  j)rocess.  This  fact  has  been 
conclusively  proved  by  numerous  experiments  (Billroth,  Tomes,  Krause, 
Kollicker,  and  others)  with  buried  ligatures  and  other  animal  tissues.  It 
was  found  that  the  establishment  of  the  suppurative  process  immediately 
arrested  resorption.  This  is  doubtless  due  to  the  fact  that  the  increase  in 
the  degree  of  the  inflammatory  i)rocess  arrests  the  function  of  the  resorp- 
tion cells  or  odontoclasts. 

Similar  conditions  are  known  to  obtain  in  the  exuviation  of  the  de- 
ciduous teeth.  Resorption  in  these  teeth  never  progresses  while  suppura- 
tion exists  about  their  roots.  This  is  doubtless  true  also  of  the  resorptive 
process  in  the  roots  of  the  permanent  teeth. 

The  examination  of  the  roots  of  rexDlanted,  transplanted,  and  imj^lanted 
teeth  reveals  the  fact  that  where  union  or  attachment  has  taken  place  with- 
out suppuration,  and  the  teeth  were  subsequently  extracted  during  some 
j)eriod  soon  after  the  ox)eration,  resorption  must  have  taken  i)lace  in  various 


512  OPERATIVE   DENTISTRY. 

locations,  for  excavations  into  the  cementum  are  plainly  seen,  and  these 
have  been  refilled  by  a  deposition  of  new-formed  cement  tissue.  Occasion- 
ally the  alveolar  tissues  never  become  tolerant  of  these  teeth,  particularly 
the  transplanted  and  the  implanted  ones,  and  under  such  circumstances 
the  resorptive  process  is  established  and  maintained  uninterruptedly  until 
the  offending  members,  which  act  as  foreign  bodies,  are  expelled  from  the 
jaws. 

Symptoms  and  Diagnosis. — The  symptoms  are  tenderness  to  per- 
cussion, a  peculiar  looseness  of  the  tooth,  which  can  be  moved  in  a  radius 
shorter  than  would  be  expected  in  a  tooth  of  normal  length  ;  later  evidences 
of  a  mild  pericementitis  appear,  and  sometimes  a  slight  discoloration  of 
the  tooth.  On  opening  the  pulp-canal  the  pulp  is  usually  found  to  be  de- 
vitalized, and  upon  passing  a  broach  into  the  canal  it  encounters  midway, 
or  in  the  upper  third  of  the  root,  a  soft,  fleshy  mass  of  tissue.  At  other 
times  the  tooth  may  contain  a  vital  pulp,  and  if  it  has  been  exposed  by 
entering  the  canal  with  a  drill,  it  must  be  devitalized ;  but  upon  its  re- 
moval and  the  exploration  of  the  pulp-cavity  the  tooth  will  be  found  to 
have  either  undergone  shortening  of  its  root,  or  the  probe  will  reveal  the 
fact  that  the  wall  of  the  pulp-chamber  has  been  invaded,  and  the  cavity 
so  made  occupied  with  a  mass  of  soft  tissue. 

In  vital  teeth  which  are  being  thus  resorbed  the  pulp  will  sometimes 
give  evidence  of  being  hypersemic  by  the  marked  increase  in  the  normal 
heat  sense  of  the  tooth,  and  its  intolerance  to  changes  of  even  a  few  degrees 
in  the  temperature  of  substances  coming  in  contact  with  it. 

In  some  of  these  cases  the  only  symptom  is  one  of  discomfort, — not 
actual  pain,  but  a  discomfort  which  the  patient  will,  perhaps,  suggest  does 
not  seem  likely  to  be  relieved  except  by  the  extraction  of  the  tooth. 

The  diagnosis  in  the  absence  of  positive  signs  may  be  made  by  exclusion. 
The  Eontgen  rays,  however,  if  available,  will  give  a  positive  diagnosis. 

Prognosis. — The  prognosis,  so  far  as  the  conservation  of  the  tooth  is 
concerned,  is  decidedly  unfavorable.  When  once  this  process  is  established 
in  a  permanent  tooth,  it  is  sooner  or  later  lost.  If  the  diagnosis  in  these 
cases  could  be  made  early,  and  the  source  of  irritation  removed  before  the 
process  of  resorption  had  progressed  to  any  considerable  extent,  it  is  possi- 
ble that  the  process  might  not  only  be  arrested,  but  that  a  redeposition  of 
tissue  would  take  place  and  the  tooth  be  preserved.  But  the  difficulty  lies 
in  the  fact  that  there  seems  to  be  no  means  of  diagnosing  the  disease  until 
it  has  gone  so  far  as  to  make  it  impossible  to  save  the  tooth. 

Treatment. — Inasmuch  as  the  only  symptoms  which  are  manifest  in 
these  cases  are  those  of  a  mild  pericementitis,  every  effort  should  be  made 
to  discover  and  remove,  if  possible,  the  cause  or  causes  of  irritation.  If 
the  tooth  is  one  that  has  been  devitalized  or  gives  evidence  of  containing 
a  dead  pulp,  the  pulp-cavity  should  be  opened  and  cleansed  ;  or  the  filling 
removed  if  one  is  found  ;  or  broken  instruments  lodged  in  the  pulp-chamber 
should  be  searched  for  and,  if  discovered,  removed.  But  if,  after  treating 
the  case  antiseptically  for  a  few  days  longer,  there  is  no  improvement  in 
the  conditions  or  abatement  of  the  symptoms,  the  tooth  should  be  extracted 
as  the  only  means  of  giving  relief. 


CHAPTBE    XXXY. 

HYPERCEMENTOSIS. 

Definition. — The  term  hypercementosis  (from  the  Latin  ccementum, 
coarse  stones,  and  hyper,  the  prefix  used  to  denote  superabundance)  means 
an  abnormal  excess  in  growth — hypertrophy — of  the  cement-tissue  of  the 
tooth. 

Hypertrophy  is  an  increase  in  the  substance  of  a  tissue  or  an  organ,  the 
result  of  an  increase  in  or  the  multiplication  of  its  elements,  and  brought 
about  in  such  a  manner  that  the  structure  of  the  hypertrophied  tissue  is 
not  materially  changed  and  does  not  differ  essentially  from  the  normal  type. 

Hypercementosis  is  therefore  a  simple  increase  in  the  volume  of  the 
elements  which  constitute  the  cement- tissue  of  the  tooth,  which  retains  in 
large  measure  the  general  character  of  the  structure  of  the  normal  tissue.  It 
may  be  circumscribed  or  diffuse,  and  may  assume  almost  any  size  or  shape. 

Causes. — The  etiologic  factors  which  produce  this  affection  are  of  two 
classes,  predisposing  and  exciting. 

The  predisposing  causes  of  hypercementosis  are  generally  the  result  of 
those  conditions,  either  constitutional  or  local,  which  induce  a  morbid 
activity  in  the  cellular  elements  of  the  peridental  membrane,  especially 
those  which  increase  its  blood-supply  beyond  the  normal.  This  condition 
may  be  produced  by  chronic  inflammatory  phenomena  resulting  from  septic 
conditions  of  the  pulp-canals  of  devitalized  teeth  or  other  cause  of  a  low 
form  of  inflammation  ;  by  malocclusion,  or  overuse  of  the  tooth,  causing 
congestion  ;  by  the  death  of  the  pulp,  which  increases  the  blood- supply  to 
the  pericementum  by  diverting  to  it  that  portion  of  blood  which  originally 
supplied  the  pulp  ;  by  the  selective  action  of  such  drugs  as  mercury, 
iodine,  etc. ,  which  produce  pericemental  irritation  and  gingivitis  ;  by  the 
irritation  of  mephitic  gases  contained  in  the  tubuli  of  devitalized  teeth 
percolating  through  the  cementum  and  inducing  chronic  pericementitis,  a 
condition  which  frequently  occurs  in  teeth  whose  pulps  have  been  removed 
and  the  canals  properly  filled  ;  while  the  presence  of  an  excess  of  uric  acid 
in  the  blood  maj'  also  be  classed  as  a  predisposing  cause,  as  it  favors  the 
deposition  of  the  urates  in  the  pericementum  and  thereby  produces  chronic 
irritation,  which  causes  congestion  of  this  membrane  and,  under  favorable 
conditions,  organization  of  the  inflammatory  exudates. 

The  tendency  of  the  pericementum  to  develop  such  excess  of  cement- 
tissue  is  undoubtedly  in  some  instances  constitutional,  and  is  especially 
marked  in  certain  individuals.  This  tendency  seems  in  some  eases  to  be 
inherited,  and  it  is  fairly  good  presumptive  evidence  that  if  the  parents 
have  developed  the  affection,  the  children  will  also  suffer  from  it. 

Exciting  Causes. — The  exciting  or  active  causes  of  the  affection  may 
be  any  form  of  irritation  which  excites  a  hypersemic  condition  of  the 
pericementum,  such  as  excessive  thermal  changes,  a  severe  strain  upon  the 

33  513 


514  OPERATIVE    DENTISTRY. 

tooth,  as  in  using  great  force  to  crush  or  incise  a  hard  or  tough  substance, 
or  the  accidental  biting  upon  some  hard  substance  like  a  piece  of  bone,  a 
shot,  or  a  piece  of  stone ;  or  an  injury  from  a  blow  or  fall ;  caries  of  the 
cervix  ;  the  projecting  edge  of  a  filling  ;  the  protrusion  beyond  the  apical 
foramen  of  a  gutta-percha  or  other  filling-material,  and  cervical  deposits 
of  salivary  calculus. 

Pathology. — Inasmuch  as  the  formation  of  cementum  is  normally  a 
more  or  less  continuous  process,  beginning  with  the  development  of  the 
root  and  the  eruption  of  the  tooth  and  ending  only  with  its  loss  or  the 
death  of  the  individual,  it  becomes  very  difficult  to  draw  the  line  at  the 
point  where  cement  formation  ceases  to  be  physiologic  and  assumes  patho- 
logic features.  An  examination  of  a  recently  erupted  tooth,  one  with  its 
root  developed  to  the  normal  length,  shows  the  cementum  to  be  composed 
of  only  a  few  concentric  layers,  while  a  tooth  from  an  elderly  person  shows 
many  such  lamellse.  But  although  the  cementum  is  thin  at  the  cervix  and 
thick  at  the  apex,  the  number  of  lamellse  are  about  the  same  in  all  parts  of 
the  tissue.  The  formation  of  the  cementum  in  lamellse  indicates  periods  of 
functional  activity  and  of  rest  upon  the  part  of  the  cementoblasts  (Figs. 
599  and  600).  These  lamellse  closely  follow  the  general  outine  of  the  dentin 
composing  the  root  and  form  an  even  and  smooth  outer  surface.  In  many 
pathologic  specimens  the  surface  presents  a  nodular  appearance,  or  larger 
globular  masses  are  formed  at  the  apex  or  upon  the  side  of  the  root,  as 
seen  in  B  and  C,  Fig.  601.  In  others,  like  the  bicuspids  and  molars,  the 
roots  may  be  united,  sometimes  by  simple  fusion  as  shown  at  A,  Fig.  601, 
at  others  by  a  considerable  mass  ;  or  the  roots  of  two  or  more  teeth  may 
be  joined  together,  as  shown  in  D,  Fig.  602.  Fig.  602,  which  is  made 
from  a  specimen  kindly  loaned  the  writer  by  Dr.  Wright,  of  Chicago, 
shows  a  similar  condition. 

Specimens  of  hypercementosis  often  show  very  great  irregularity  in 
the  lamellation  and  in  the  surface  of  the  dentin.  At  certain  points  deep 
excavations  appear  in  the  surface  of  the  dentin,  while  other  similarly  ap- 
pearing excavations  are  filled  with  cement  tissue  which  has  no  regular 
lamellated  structure.  Extensive  areas  of  absorption  upon  one  part  of  the 
root  and  large  additions  of  new  tissue  upon  another  part  may  be  observed 
in  the  same  specimen. 

The  character  of  the  irritation  which  has  stimulated  the  activity  of 
the  formative  function  of  the  cementoblasts  is  indicated  by  the  surface  of  the 
new-formed  cementum  ;  the  smoother  and  more  regularly  globular  its 
form  (Fig.  603),  the  more  continuously  chronic  has  been  the  i^rocess, 
while  if  the  surface  is  irregular  or  composed  of  numerous  elevations  and 
depressions,  it  is  an  evidence  of  irregularity  in  the  character  of  the  irri- 
tation, and  indicates  intermittent  attacks  of  resorption  and  deposition. 

When  such  teeth  are  extracted  the  pericementum  is  found  to  be  much 
thickened  and  abnormally  vascular.  Sometimes  there  will  be  found 
adherent  to  the  irregular  surface  of  the  new-formed  cementum  certain 
flesh-like  masses  which  remind  one  of  the  absorbent  organ  found  attached 
to  exuviating  deciduous  teeth. 

Examined  microscopically,    the  new-formed   cementum  is  shown  to 


i' " 


'1 


I  4 


*    v-* 


Dentin 


/    V 


Cementum 


Fig.  599. — Transverse  section  of  root  of  human  tooth  near  the  apex,  showing  dentin  and  cementum 

in  hypercementosis.    X  200. 


Cementum 


Lamellae 


Canaliculi 


Pig.  600. — Transverse- section  of  root  of  human  tooth  near  the  apex,  showing  the  dentin  and  the  ce- 
mentum.   X  175. 


Fig.  601. 
B  C 


M^^K  ^  ^^H     .^^^K^ 


Fig.  602. 


Fig.  603. 


Fig.  604.— Transverse  section  of  root  of  human  molar,  hypercementosis.    X  96. 


Fig.  605.— Vertical  section  of  root  of  human  molar,  hypercementosis.     X  15. 


Dentin 


Fig.  606. — Transverse  section  of  roots  of  human  molar,  near  apex.     X  75. 


Fig.  607. — Transverse  section  of  root  of  human  tooth,  hypercementosed,  showing  the  irregular  character 

of  the  new-formed  tissue.     X  75. 


Fig.  608. — Transverse  section  of  alveolus  and  apex  of  root  of  abscessed  human  molar,  showing  resorption 
area  partially  refUled  with  a  secondary  formation  of  cementum.     X  96. 


Enamel  pearl 


Fig.  609. — Case  of  inostosis,  with  formation  of  a  pearl-like  globule  resembling  enamel. 


Fig.  610. — Transverse  section  of  root  of  human  tooth,  showing  ease  of  inostosis.     X  80. 


HYPERCEMENTOSIS.  515 

possess  the  characteristic  general  structure  of  cementum,  but  differing  in 
the  size,  number,  and  arrangement  of  the  lacunsB  and  canaliculi,  the  thick- 
ness of  the  lamellse,  and  the  distinctness  of  the  incremental  lines  of 
Salter  (Fig.  604).  These  differences  depend  in  large  measure  upon  the 
extent  or  thickness  of  the  new- formed  tissue.  In  normal  cementum  the  thin 
laminae  at  the  cervix  of  the  tooth  present  no  lacunae,  but  as  the  apex  is 
approached  they  become  more  and  more  abundant,  as  do  also  the  canal- 
iculi. Similar  variations  occur  in  the  hypertrophied  cement  tissue  (Fig. 
605). 

Vascular  or  medullary  canals  (Haversian  canals)  are  exceptional  in 
normal  cementum,  but  they  are  frequently  found  in  hypercementosis. 
The  presence  of  these  canals  in  the  cementum  is  not,  however,  necessarily 
an  evidence  of  pathologic  conditions,  for  they  are  occasionally  found  in 
very  thick  cementum  of  normal  teeth,  particularly  where  two  roots  are 
joined  together  by  cement  tissue,  as  shown  in  Fig.  606. 

In  hypercementosis  having  a  smooth  and  regular  surface  the  lamellae 
are  fairly  regular  and  the  incremental  lines  of  Salter  generally  well 
marked.  The  lacunae  are  more  numerous  and  slightly  larger"  than  in 
normal  cementum,  but  irregularly  arranged  and  with  the  canaliculi 
running  in  a  peripheral  direction,  as  seen  in  normal  tissue. 

When  the  surface  of  the  new  tissue  is  irregular  the  character  of  the 
structure  is  more  or  less  irregular.  The  lamellae  are  not  so  distinctly 
marked  and  the  lacunae  have  a  more  irregular  arrangement.  These  con- 
ditions are  strikingly  shown  in  Fig.  607. 

The  density  and  texture  of  the  various  lamellae  often  differ  considerably  ; 
some  seemingly  are  very  perfectly  calcified,  with  few  or  no  lacunae,  while 
in  others  calcification  is  quite  imperfect  and  the  lacunae  are  very  numerous. 
In  some  cases  lamination  is  not  traceable  in  the  new-formed  tissue,  which 
fact  would  indicate  that  the  functional  activity  of  the  cementoblasts  had 
been  continuous,  that  there  had  been  no  periods  of  rest,  no  abatement  in 
the  stimulation  or  irritation. 

INOSTOSIS. 

A  most  curious  condition  is  sometimes  noticed  in  the  structural  arrange- 
ment of  the  new  cement  tissue,  a  condition  which  unmistakably  indicates 
that  lamellae  already  formed  had  been  partially  removed  by  resorption, 
and  the  excavations  thus  made  afterwards  filled  by  a  redeposition  of  cement- 
tissue,  as  shown  in  Fig,  608.  The  process  by  which  cement-tissue  is  re- 
formed in  the  excavations  made  by  resorption  has  been  termed  by  Henry 
inostosis.  The  new-formed  tissue  in  inostosis  is  sometimes  of  very  peculiar 
character.  Occasionally  it  resembles  osteodentin,  at  other  times  it  has  the 
appearance  of  enamel.  Fig.  609  is  a  case  from  the  private  collection  of  the 
writer  which  shows  a  pearl-like  body  in  the  side  of  the  root  of  a  third 
lower  molar,  occupying  a  cavity  apparently  formed  by  resorption.  Fig. 
610  is  a  microscopic  section  of  a  similar  case  from  the  private  collection 
of  Dr.  Y.  A.  Latham,  but  lying  deeper  in  the  dentin. 

These  phenomena  represent  two  distinct  vital  processes,  processes 
which  are  antagonistic  to  each  other.     One  is  formative,  the  other  de- 


516  OPERATIVE   DENTISTRY. 

structive.  The  explanation  would  seem  to  lie  in  the  character  and  degree 
of  the  irritation,  operating  at  different  i)eriods  or  in  different  locations  at 
the  same  period. 

It  has  already  been  noticed  that  a  mild  and  continuous  chronic  irri- 
tation of  the  peridental  membrane  favors  the  production  of  new  cement- 
tissue  through  stimulation  of  the  cementoblasts,  while  it  is  a  recognized 
fact  that  another  form  of  irritation,  which  is  perhaps  only  a  little  more 
severe,  will  establish  a  retrograde  or  destructive  process  in  the  tissues,  as 
noted  in  the  resorption  of  bone  by  the  stimulation  of  the  osteoclasts.  A 
similar  condition  doubtless  takes  place  in  the  resorption  of  the  cementum, 
for  there  are  often  found  attached  to  such  teeth  masses  of  tissue  composed 
of  giant-cells  which  cannot  be  distinguished  from  the  multinucleated  cells 
found  in  the  "  absorbent  organ"  attached  to  exuviating  deciduous  teeth. 
It  has  never  been  definitely  determined  whether  there  are  two  distinct  sets 
of  cells — cementoblasts  and  cementoclasts — or  whether  the  cementoblasts 
under  different  stimuli  do  not  perform  both  functions  of  formation  and 
of  resorption. 

Specimens  are  occasionally  exhibited  in  which  well-marked  resorption 
was  present  upon  one  side  and  hypercementosis  upon  the  other,  which 
would  indicate  that  these  processes  were  the  result  of  localized  irritations 
of  different  degrees. 

Although  this  excessive  growth  of  the  cementum  may  result  in  the 
fusion  of  the  roots  of  a  tooth,  or  of  the  roots  of  contiguous  teeth,  or  of  the 
crown  of  one  tooth  with  the  roots  of  another,  as  shown  in  Dr.  Wright's 
specimen  (Fig.  602),  no  authentic  evidence,  to  the  knowledge  of  the  writer, 
has  so  far  been  i^resented  of  fusion  of  the  cementum  with  the  alveolar  pro- 
cess. Bones  often  become  auchylosed  by  fusion  of  their  surfaces,  the  result 
of  the  healing  xjrocess,  as,  for  instance,  in  the  temporo-maxillary  articula- 
tion following  traumatisms  or  inflammation  of  the  joint.  Sometimes  the 
new-formed  tissue  in  hypercementosis  seems  to  establish  a  union  with  the 
alveolus,  and  when  the  tooth  is  extracted  it  not  infrequently  causes  one  of 
the  plates  of  the  alveolar  process  to  be' fractured  and  brought  away  adherent 
to  the  root ;  but  upon  a  closer  examination  it  is  found  that  the  bone  can  be 
detached  from  the  hypertrophied  cement  tissue  after  more  or  les3  effort,  as 
the  tissues  remain  separated  by  a  modified  i)ericemental  membrane,  the 
fibres  of  which  seem  to  be  very  strong  and  firmly  attached  to  both  tissues. 

Symptoms  and  Diagnosis. — The  local  symptoms  of  hypercementosis 
are  usually  negative,  and  unless  the  affection  causes  pain  in  the  tooth  or  its 
surroundings  its  presence  may  never  be  suspected. 

Occasionally,  however,  the  patient  may  complain  of  symptoms  which 
would  indicate  pericemental  irritation, — viz.,  slight  soreness  and  elonga- 
tion, tenderness  to  percussion,  and  pain  in  the  region  of  the  tooth.  Some- 
times tumefaction  of  the  alveolar  process  over  the  root  may  be  observable 
and  this  may  be  slightly  tender  to  pressure,  but,  as  a  rule,  no  such  positive 
diagnostic  signs  are  presented. 

When  j)ain  is  present,  it  is  usually  of  the  reflex,  neuralgic  order,  and 
generally  referred  to  some  remote  portion  of  the  face  or  head  or  to  the 
eyes  or  the  ears.     Numerous  cases  have  been  placed  on  record  from  time  to 


HYPERCEMENTOSIS.  517 

time,  in  tlie  periodical  dental  and  medical  literature,  of  persistent  neural- 
gias in  these  locations  and  of  functional  disorders  of  the  eyes  and  ears, 
which  have  been  traced  to  the  presence  of  hypercementosis  of  the  teeth, 
and  the  diagnosis  has  been  proved  by  the  cure  of  these  affections  following 
the  extraction  of  the  teeth. 

Serious  derangement  of  the  general  nervous  system  may  also  result  from 
this  form  of  irritation.  Tomes*  mentions  ^'two  cases  in  which  epilepsy 
appeared  to  be  dependent  upon  diseased  teeth,  the  most  prominent  feature 
being  hypercementosis  of  the  roots." 

Chorea  has  also  been  traced  to  the  irritation  of  diseased  teeth,  particu- 
larly to  pulp  irritation  and  hypercementosis.  These  nervous  diseases  are 
common  in  institutions  for  feeble-minded  children,  and  it  was  the  experi- 
ence of  the  writer  when  serving  upon  the  staff  of  one  of  these  institutions 
that  many  times  dental  irritation  was  the  cause  of  these  affections,  as 
was  proved  by  the  abatement  of  the  symptoms  after  the  extraction  of  the 
offending  teeth. 

The  diagnosis  of  hypercementosis  is  often  a  problem  which  presents  the 
greatest  difficulties,  and  in  many  cases  it  can  only  be  reached  by  a  process 
of  exclusion.  Pain  or  other  symptoms  of  uneasiness  which  are  not  refer- 
able to  any  other  cause  may  be  the  only  symptoms  present.  The  patient 
sometimes  says  the  tooth  feels  enlarged  or  swollen  and  sensitive  to  percus- 
sion, but  these  again  may  be  the  only  symptoms  to  guide  in  the  diagnosis. 

Many  persons  are  subjects  of  hypercementosis,  sometimes  to  a  consid- 
erable extent,  without  ever  having  suffered  the  least  inconvenience  there- 
from, this  condition  of  the  teeth  not  being  recognized  until,  for  some  other 
reason,  the  teeth  have  been  extracted. 

The  best  and  most  reliable  means  of  diagnosing  hypercementosis  is  by 
means  of  the  Eontgen  rays.  The  picture  thus  obtained,  if  made  by  an 
experienced  operator,  brings  out  the  outlines  of  the  teeth  and  the  position 
and  size  of  their  roots  in  such  a  clearly  defined  manner  that  the  diagnosis 
of  hypercementosis,  if  it  existed,  could  not  help  but  be  correctly  made. 

It  is  not  necessary  for  the  dental  surgeon  to  go  to  the  expense  of  buying 
apparatus  for  this  purpose,  for  all  large  cities,  and  nearly  all  first-class  hos- 
pitals, have  such  facilities  for  diagnosis  and  expert  attendants  ready  to 
photograph  any  part  of  the  body  that  may  be  desired,  and  thus  relieve  the 
dental  adviser  of  all  anxiety  as  to  obtaining  a  good  picture,  or  of  the  fear 
of  accidents  which  sometimes  come  as  a  result  of  oft-repeated  or  long 
exposure  to  the  effects  of  the  Crookes  tube. 

Treatment. — The  only  treatment  to  be  recommended  for  hypercemen- 
tosis is  the  immediate  extraction  of  the  diseased  tooth  as  soon  as  the  diag- 
nosis is  assured.  Immediate  relief  is  not  always  obtained,  but  usually, 
even  in  the  severest  forms  of  iic  douloureux  dependent  upon  this  cause,  the 
pain  will  abate  after  a  few  days.  Functional  affections  of  the  eyes  and  ears 
which  have  hypercementosis  as  their  cause,  rapidly  improve  after  the 
extraction  of  the  tooth.  In  the  general  nervous  affections  dependent  upon 
the  same  cause  equally  favorable  results  follow. 

*  Dental  Surgery,  4th  edition,  p.  471. 


CHAPTEE    XXXVI. 

NECROSIS   OF  THE   TEETH, 

Definition. — The  term  necrosis  (Greek,  vexpoq^  dead)  is  generally  used 
in  its  broadest  sense  to  indicate  death  in  any  form,  whether  death  of  indi- 
vidual cells,  aggregations  of  cells,  or  masses  of  complex  tissues. 

In  its  more  restricted  sense  it  is  used  to  indicate  death  of  tissue  en  masse, 
while  the  term  necrobiosis  is  used  to  indicate  death  of  cells.  In  surgery 
the  term  necrosis  is  still  farther  restricted,  and  is  generally  applied  to 
death  en  masse  of  bone  and  like  hard  structures,  while  the  term  gangrene 
is  applied  to  death  en  masse  of  soft  tissues. 

The  term  necrosis  would  therefore,  when  applied  to  the  teeth,  indicate 
death  en  masse  of  these  organs. 

The  teeth  receive  their  blood-supply  and  nutrition  from  two  sources, — 
viz.,  from  the  pulp  and  from  the  j)eridental  membrane.  The  character  of 
the  teeth  is  such  that  the  vitality  of  the  pulp  of  a  diseased  tooth  may  be 
destroyed  and  the  tooth  still  retained  in  the  jaw  for  an  indefinite  period, 
through  its  organic  connection  with  the  alveolus,  by  means  of  the  cemen- 
tum  and  the  pericementum.  If,  however,  the  vitality  of  the  jjericemen- 
tum  is  destroyed,  the  tooth  has  no  further  vital  connection  with  the  alveo- 
lus, for  under  such  circumstances  the  same  cause  which  destroyed  the  peri- 
cementum will  also  destroy  the  pulp,  when  the  tooth  may  be  termed 
necrosed,  and  it  is  exfoliated  as  a  foreign  body.  Nature  is  always  intol- 
erant of  any  useless  or  dead  member  and  immediately  sets  in  operation 
certain  forces  to  rid  itself  of  the  incubus.  The  expulsion  or  exfoliation 
of  a  necrosed  tooth  is  attended  with  more  or  less  local  inflammation  and 
suppuration  of  the  surrounding  parts,  the  integrity  of  which  will  depend 
upon  the  cause  of  the  necrosis  and  the  condition  of  the  surrounding  tissues. 

When  death  of  the  pulp  occurs  a  partial  necrosis  of  the  dentin  follows, 
but  this  from  the  clinic  stand-point  does  not  mean  the  loss  of  the  tooth,  for 
such  teeth,  if  jjroperly  treated  by  extirj^ating  the  devitalized  pulj)  and  fill- 
ing the  canals,  may  remain  without  untoward  symptoms  as  useful  members 
of  the  dental  arch  for  many  years,  though  they  are  not  as  valuable  nor 
generally  so  long  preserved  as  teeth  with  vital  pulps.  The  probabilities 
are  that  the  dentin  may  still  receive  under  such  circumstances  a  certain 
amount  of  nutrition  through  the  cementum  and  the  granular  layer  of  Pnr- 
kinje.  This,  however,  is  not  endorsed  by  some  authorities.  A  tooth 
which  has  lost  the  vitality  of  its  pulp  is,  therefore,  strictly  speaking,  in  a 
state  of  partial  necrosis.  Some  authorities  have  maintained  that  in  cer- 
tain debilitated  conditions  of  the  pericementum  the  devitalization  of  the 
pulp  would  prove  helpful  in  establishing  more  normal  conditions  in  it 
by  diverting  the  blood,  which  was  originally  intended  to  supply  the  pulp, 
to  the  vessels  of  the  pericementum.  It  is  somewhat  doubtful  whether  the 
vessels  of  the  pericementum  could  carry  the  extra  supply  of  blood  without 
518 


NECROSIS   OF   THE   TEETH.  519 

producing  an  abnormal  hypersemia,  and  thus  defeat  the  very  object  that 
the  operation  was  intended  to  secure. 

Necrosis  of  the  cementum  is  due  to  the  destruction  of  the  pericementum, 
as  this  membrane  is  its  principal  means  of  nutrition  during  the  vitality  of 
the  tooth  and  its  only  means  after  the  devitalization  of  the  pulp.  J^ecrosis 
of  the  cementum  may  be  partial  or  complete.  Partial  necrosis  of  the  cemen- 
tum is  common,  but  complete  necrosis  is  rare. 

Causes. — The  causes  of  necrosis  may  be  divided  into  systemic,  or 
general,  and  local ;  predisposing  and  exciting. 

The  general  predisposing  causes  are  all  those  conditions  which  in  any 
way  produce  debility  or  disease  of  the  pericementum,  while  the  exciting 
systemic  causes  may  be  such  diseases  as  syphilis,  scurvy,  mercurialism, 
iodism,  etc. 

The  predisposing  local  causes  are  malocclusions,  loss  of  occlusion,  local 
inflammatory  conditions  of  the  gums  and  alveolar  process,  and  death  of 
the  pulp. 

The  local  exciting  causes  may  be  mechanic  irritants,  like  cervical  salivary 
deposits  or  a  rubber  band  which  has  been  placed  upon  the  crown  of  the 
tooth  and  has  been  lost  beneath  the  gum  ;  the  pressure  from  an  ill-fitting 
crown,  clasp,  or  plate  ;  root  fillings  which  have  passed  the  apical  canal 
and  impinge  upon  the  apical  tissues  ;  chemic  irritants  like  arsenic,  chromic 
acid,  and  caustic  potash  ;  septic  conditions  arising  from  a  devitalized  jjulp 
or  from  unhygienic  conditions  of  the  mouth  ;  phagedenic  and  gouty  peri- 
cementitis, and  severe  traumatisms  like  blows  and  falls  or  the  too  rapid 
movement  of  the  teeth  in  regulating. 

Partial  necrosis  of  the  cementum  may  vary  in  extent  from  a  very  small 
area  at  the  apex  of  a  single-rooted  tooth  to  an  entire  root  of  a  double-  or 
treble-rooted  tooth.  The  cementum  is  rarely  necrosed  in  teeth  having 
vital  pulps,  as  is  evidenced  by  the  fact  that  in  the  recession  of  the  peri- 
cementum, gum,  and  alveolus,  which  sometimes  occurs  from  diseases  affect- 
ing these  tissues,  the  cementum  usually  maintains  its  sensitiveness  and 
responds  vigorously  to  all  forms  of  irritation  whenever  the  influences  of 
these  agents  are  brought  to  bear  upon  it.  ISTecrosis  of  the  cementum, 
either  in  part  or  in  whole,  is  therefore  dependent  upon  death  of  the  pulp 
and  upon  partial  or  complete  destruction  of  the  peridental  membrane. 

The  most  common  form  of  partial  necrosis  is  that  which  occurs  at  the 
apex  of  the  root  following  alveolar  abscess. 

In  these  cases  the  apex  of  the  root  is  denuded  of  its  pericementum  by 
the  septic  inflammation  which  has  been  present  in  the  apical  space  and 
the  denuded  portions  bathed  in  pus  for  a  considerable  period.  This 
necrosed  tissue,  however,  when  not  too  extensive,  may,  if  the  septic  con- 
ditions are  removed,  be  resorbed,  and  later  a  redeposition  of  Cement  tissue 
take  place  as  described  in  the  chapter  on  "Resorption  of  the  Teeth." 

Another  but  less  common  form  of  partial  necrosis  of  the  cementum  is 
that  in  which  an  entire  root  of  a  multirooted  tooth,  most  often  the  lingual 
root  of  the  superior  molars,  may  be  entirely  divested  from  the  cervix  to 
ihe  apex  of  its  pericemental  membrane,  alveolar  process,  and  gum,  or  the 
gum  and  alveolar  process  may  remain  intact. 


520  OPERATIVE   DENTISTRY. 

Such  conditions  usually  occur  in  pulpless  teeth,  but  occasionally  the 
pulp  in  the  exposed  root  only  will  be  dead,  while  in  the  others  it  may 
still  be  vital  and  the  tooth  firmly  held  in  place  by  the  attachment  of 
the  buccal  roots.  If  under  such  circumstances  the  tooth  is  opened,  the 
living  portions  of  the  pulp  devitalized  and  extirpated,  and  the  root- canals 
filled,  the  lingual  root  may  be  amputated  with  engine  burs  or  disks  and 
the  balance  of  the  tooth  allowed  to  remain.  Teeth  treated  in  this  manner 
have  been  known  to  do  good  service  for  several  years. 

Conijjlete  necrosis  of  the  cementum  may  be  caused  by  acute  or  chronic 
inflammatory  conditions  of  the  pericementum  which  may  be  dependent 
upon  general  or  local  conditions. 

When  complete  necrosis  of  the  cementum  has  occurred  as  the  result 
of  an  acute  inflammation  of  the  pericementum,  the  tooth  is  no  longer 
tolerated  by  the  system,  but  becomes  as  a  foreign  body  and  is  speedily 
expelled.  Under  these  circumstances  the  tooth  is  in  a  septic  condition, 
and  the  inflammatory  process  which  is  established  as  a  result  of  septic  irri- 
tation is  often  very  active,  causing  great  pain,  suppuration  and  discharge 
of  pus  at  the  cervix,  considerable  tenderness  and  swelling  of  the  gums  and 
surrounding  tissues,  and  looseness  of  the  tooth,  which  after  a  few  days  or 
weeks  is  either  picked  out  with  the  fingers  or  drops  out. 

When  complete  necrosis  occurs  as  a  result  of  a  chronic  inflammation, 
the  process  of  expulsion  is  usually  very  slow,  chronic  suppuration,  loose- 
ness of  the  tooth,  and  periodical  soreness  being  the  chief  symptoins,  and 
several  months  or  years  may  be  required  for  its  complete  exfoliation. 
Fig.  611  shows  a  superior  central  incisor  which  was  completely  necrosed 
and  expelled  as  a  result  of  chronic  inflammation  induced  by  drilling 
through  the  side  of  the  root  and  of  the  protrusion  through  the  opening 
of  a  gutta-percha  filling.  The  root  is  slightly  eroded  uj)on  the  labial 
surface  by  the  action  of  the  odontoclasts,  and  a  thin  scale  of  calcic 
concretion  has  formed  upon  the  lingual  surface.  Fig.  612  is  a  crowned 
superior  central  incisor  which  had  lost  its  natural  crown  by  a  traumatism 
while  the  lad  was  playing  ball.  The  root  had  been  filled  with  cotton  and 
the  crown  set  with  cement.  For  several  years  the  tooth  had  been  loose, 
and  was  finally  extracted  with  the  fingers.  Extensive  resorption  had  taken 
place  at  the  apex,  exposing  the  apical  end  of  the  cotton  filling. 

Fig.  613  is  a  transplanted  superior  central  incisor  which  had  been 
crowned  before  transplanting.  For  six  years  the  tooth  did  well,  when 
suddenly  it  became  very  sore  and  loose,  and  was  expelled  after  a  few  weeks. 
On  the  distal  surface  at  the  cervix  is  a  depression  caused  by  resorption 
which  has  penetrated  to  the  pulp-canal,  exposing  the  cement  with  which 
it  was  filled.  Fig.  614,  a  necrosed  superior  cuspid,  was  the  seat  of  a 
chronic  abscess  for  many  years ;  the  tooth  finally  became  so  loose  that  it 
was  extracted  with  the  fingers  ;  it  shows  extensive  resorption  at  the  apex. 

In  cases  of  complete  necrosis  of  the  cementum  the  only  treatment  is 
extraction. 


Gutta-percha 
filling 


Fig.  611. 


Fig.  Gil. 


Fig.  61.5. — Epithelial  scales  and  salivary  corpuscles  from  sotdes  of  the  mouth.    X  50. 


CHAPTEE    XXXVII. 

DEPOSITS   UPON   THE   TEETH.      GEEEN   STAINS.       CALCIC   DEPOSITS. 

Green  Stains. — The  simplest  deposits  that  are  found  upon  the  teeth 
are  the  green  stains  so  common  at  the  margin  of  the  gums  upon  the  anterior 
teeth  of  children  and  young  people  and  persons  of  adult  age  who  pay 
little  attention  to  the  cleanliness  of  their  mouths. 

These  deposits  are  probably  formed  by  the  growth  of  the  leptothrix 
buccalis  and  certain  forms  of  chromogenic  mouth-bacteria  which  have 
attached  themselves  to  remains  of  ]S"asmyth's  membrane  or  a  roughened 
surface  of  the  enamel. 

Their  continued  presence  causes  a  softening  and  disintegration  of  the 
polished  surface  of  the  enameh  which  leads  to  decay.  It  is,  therefore, 
important  that  they  should  be  removed  early,  and  if  the  enamel  has  become 
eroded  it  should  be  ground  smooth  with  fine  Arkansas  stones  and  polished 
with  fine  pumice  and  precipitated  chalk. 

Calcic  Deposits. — The  calcic  deposits  which  are  formed  upon  the 
teeth  are  classed  as  salivary  and  serumal,  or  as  '■'■ptyalogenic'^  and  ^^  hema- 
togenic^' (Pierce).  The  first  are  formed  from  the  calcic  elements  of  the 
saliva,  the  second  from  the  calcic  elements  of  the  blood,  combined  with 
certain  waste  or  end-products  formed  from  imperfect  metabolism. 

The  formation  of  salivary  deposits  is  usually  the  result  of  local  causes, 
but  certain  general  conditions  act  as  predisposing  factors.  The  formation 
of  serumnal  deposits  is  largely  the  result  of  constitutional  conditions,  as,  for 
instance,  rheumatism  and  gout,  febrile  diseases,  and  certain  kidney 
affections,  like  diabetes  and  albuminuria,  which  may  produce  local  necro- 
biosis of  the  pericementum,  terminating  in  pus  formation  or  in  caseous  or 
calcic  degeneration  of  the  pus  and  the  formation  of  adherent  concretions. 

The  saliva  of  the  human  mouth  always  contains  calcic  salts  in  greater 
or  less  quantity.  These  salts  are,  under  certain  conditions,  deposited 
upon  the  teeth  or  in  the  ducts  of  the  glands  in  the  form  of  concretions  or 
calculi,  which  are  more  or  less  hard  and  mixed  with  epithelial  scales,  lep- 
tothrix, and  food  debris.  The  deposit  or  concretion  thus  formed  upon  the 
teeth  is  called  salivary  calculus,  or  "tartar,"  and  the  concretions  formed 
within  the  salivary  ducts  are  termed  salivary  calculi. 

These  deposits  are  found  in  greatest  abundance  upon  the  surfaces  of 
those  teeth  which  are  situated  opposite  the  ducts  of  the  salivary  glands, — 
viz.,  the  buccal  surfaces  of  the  first  and  second  superior  molars,  and  the 
lingual  surfaces  of  the  inferior  incisors  and  cuspids,  and  in  those  locations 
where  the  conformation  of  the  teeth  renders  the  deposits  least  liable  to  be 
disturbed, — viz.,  upon  the  proximate  surfaces  and  crevices  of  the  teeth 
beneath  the  free  margins  of  the  gums. 

Composition  of  the  Saliva. — The  most  important  constituents  of 
normal  mixed  saliva  are  ptyalin, — a  diastatic  ferment, — mucin,  and  the 

521 


522  OPERATIVE   DENTISTRY. 

clilorides  of  sodium  and  potassium  ;  in  addition  to  these  there  are  found 
traces  of  albumin,  fat,  potassium  sulphocyanide,  sulphates  and  phosjDhates  of 
the  alkalies  and  alkaline  salts,  principally  calcic  phosphate,  also  calcic  car- 
bonate and  oxide  of  iron.  Occasionally  there  are  found  also,  even  in  normal 
saliva,  traces  of  urea  and  ammonium  nitrite. 

The  average  daily  amount  of  saliva  excreted  ranges  from  800  to  1500 
grammes,  or  from  a  little  less  than  a  quart  to  three  pints.  Tomes  places  it 
at  from  13  ounces  to  82  pounds. 

According  to  Lehmann,  the  specific  gravity  of  the  saliva  ranges  in 
health  from  1004  to  1006.  He  states,  however,  that  it  may  rise  to  1008  or 
1009  or  even  sink  to  1002  without  the  evidence  of  any  existing  disease. 

According  to  Berzelius,  normal  mixed  saliva  gives  the  following 
analysis : 

Water 992.9 

Solids 7.1 

Ptyalin 2.9 

Mucin 1.4 

Sulphocyanide 1.4 

Salts 1.9 

According  to  Frerichs, — 

Water 994.10 

Solids 5.90 

Epithelium  and  mucus 2.13 

Fat 0.07 

Mucin  and  traces  of  alcoholic  extract 1.41 

Potassium  sulphocyanide 0.10 

Chlorides  of  sodium  and  potassium,  phosphates  of  sodium  and  po- 
tassium, and  oxide  of  iron 2.19 

According  to  Jacobowitsch, — 

Water 99.51 

Solids 0.49 

Soluble  organic  bodies,  ptyalin,  etc 0. 130 

Epithelium 0.160 

Inorganic  salts 0. 182 

Potassium  sulphocyanide 0.006 

Potassium  and  sodium  chloride 0.084 

The  saliva  as  found  in  the  mouth  is  a  mixed  fluid,  being  composed  of 
the  secretions  of  the  various  salivary  glands — parotid,  submaxillary,  and 
sublingual — and  of  the  oral  mucous  glands,  its  chemic  and  physic  prop- 
erties varying  as  the  secretion  from  one  or  the  other  of  these  glands  may 
predominate.  In  character  it  is  generally  a  clear  viscid  or  glairy  fluid, 
containing  epithelial  cells,  mucous  corpuscles,  and  salivary  corpuscles. 
The  character,  however,  often  varies  considerably ;  at  times  it  may  be  a 
thin,  watery  fluid,  at  other  times  thick  and  ropy. 


DEPOSITS   UPON   THE   TEETH.  523 

The  chemic  reaction  of  mixed  saliva  is  slightly  alkaline,  but  when  the 
secretions  are  scanty  it  may  give  a  very  slightly  acid  reaction.  Saliva 
tested  in  the  mouth  with  litmus  paper  often  gives  an  acid  reaction ;  but 
this  is  many  times  due,  no  doubt,  to  the  formation  of  acids  within  the 
mouth  from  the  fermentative  action  of  the  acid-producing  bacteria  upon 
alimentary  debris. 

The  excretion  of  the  parotid  gland  contains  a  trifle  more  water  and  is 
less  viscid  than  the  secretions  of  sublingual  and  submaxillary  glands ;  it 
contains  ptyalin,  but  no  mucin ;  its  calcic  constituents  are  the  carbonate 
and  phosphate,  the  calcium  phosphate  being  in  minute  amount.  Accord- 
ing to  Hoppe-Seyler,  the  inorganic  elements  amount  to  0.34  per  cent. 

The  secretions  of  the  sublingual  and  submaxillary  glands  are  poor  in  ptyalin 
but  are  rich  in  mucin  ;  the  sublingual  contains  the  highest  per  cent.  Car- 
bonate and  phosphate  of  calcium  are  found  in  about  equal  proportions. 
These  elements  amount  to  about  0.43  per  cent,  in  the  submaxillary  se- 
cretion, but  the  percentage  is  not  so  high  in  the  secretion  of  the  sub- 
lingual. 

The  secretion  of  the  mucous  glands  contains  a  large  amount  of  mucin. 
The  organic  and  inorganic  constituents  average  about  20  parts  to  1000. 

The  calcic  substances  of  the  saliva  are  held  in  solution  by  the  presence 
of  a  sufficient  quantity  of  carbon  dioxide  (COJ.  This  combination,  how- 
ever, is  so  unstable,  that  as  soon  as  the  saliva  is  exposed  to  the  oxygen 
of  the  atmosphere  or  to  the  acids  of  fermentation  produced  in  the  mouth, 
or  is  at  rest,  the  carbon  dioxide  escapes,  and  the  calcic  elements,  being  no 
longer  able  to  maintain  solubility,  are  precipitated  and  collect  ujion  the 
teeth,  thus  forming  what  is  known  as  salivary  calculus,  or  tartar. 

It  is  necessary,  however,  that  the  enamel  be  roughened  or  uneven,  or 
that  leptothrix  threads  have  found  attachment  to  I^asmyth's  membrane  or 
the  enamel,  in  order  that  a  nidus  be  presented  for  the  formation  of  the 
concretion. 

The  viscid  tenacious  character  of  the  saliva,  however,  is  sufficient  to 
form  a  nidus  for  the  collection  of  tartar  upon  the  teeth  when  for  any  reason 
— but  particularly  in  the  continued  fevers  and  other  wasting  diseases — the 
mucin  becomes  dried  upon  the  teeth,  forming  masses  of  sordes.  These 
masses  of  dried  mucin  contain  innumerable  epithelial  scales  and  salivary 
corpuscles.  See  Fig.  615.  It  is  possible,  also,  that  the  particles  of  the 
calcic  deposit  are  held  together  by  the  agglutinating  effect  of  the  coagulated 
mucin. 

Kirk,  however,  believes  there  is  a  more  intimate  relation  between  the 
organic  substances  and  the  calcic  elements  of  the  tartar  than  their  mere 
cementing  properties.  He  thinks  conditions  exist  which  are  somewhat 
similar  to  those  under  which  calcoglobulin  is  formed,  and  suggests  that 
salivary  calculi  bear  a  family  resemblance  to  calcoglobulin. 

Salivary  calculus  is  composed,  according  to  Berzelius,  of : 

Phosphates  of  calcium  and  magnesium 79.0 

Salivary  mucus 12.5 

Ptyalin 1.0 

Animal  matter  soluble  in  HCI 7.5 


524  OPERATIVE   DENTISTRY. 

According  to  Charles,  its  average  composition  is  as  follows  : 

Calcium  phosphate 55  to  64 

Calcium  carbonate 7  to    8 

Ferric  phosphate 1  to    3 

Kesidue  :  organic  matter,  salts  of  alkalies,  silica,  etc 24  to  28 

There  is  a  wide  difference  in  these  two  analyses,  but  this  may  possibly 
be  explained  by  the  difference  in  the  location  from  which  the  sj>ecimens 
were  probably  taken. 

It  is  but  natural  to  suppose  that,  inasmuch  as  the  parotid  secretion  con- 
tains an  abundance  of  calcium  carbonate  and  only  a  minute  amount  of 
calcium  phosphate,  the  concretions  formed  upon  the  teeth  opposite  Steno's 
duct  would  be  composed  largely  of  calcium  carbonate ;  while,  upon  the 
other  hand,  the  concretions  formed  upon  the  lower  incisors  opposite  the 
ducts  of  Wharton  would  be  composed  equally  of  calcium  carbonate  and 
calcium  phosphate,  as  the  secretions  of  the  sublingual  and  submaxillary 
glands  contain  about  equal  portions  of  these  salts. 

Magitot  claimed  that  the  salivary  calculus  formed  in  the  region  of  the 
parotid  glands  was  almost  wholly  carbonate,  while  that  formed  upon  the 
inferior  central  incisors  was  largely  phosphate. 

Alfred  Vergne  claimed  that  the  calculus  formed  upon  the  superior 
molar  teeth  had  less  phosphate  than  that  upon  the  inferior  incisors,  but 
that  the  carbonate  was  about  equally  distributed. 

Salivary  calculi,  or  the  concretions  found  in  the  ducts  of  the  salivary 
glands,  are  iisually  composed  largely  of  calcium  phosphate.  They  are 
generally  of  an  elongated  form,  dirty  yellow  to  brown  in  color,  and  are 
formed  in  concentric  layers.  They  contain  no  leptothrix,  and  vary  in 
size,  form,  appearance,  and  composition. 

The  following  table,  prepared  by  Charles,  gives  the  average  compo- 
sition : 

Calcium  phosphate 30  to  80  per  cent. 

Calcium  carbonate 11  to  15    "     " 

Organic  matter 5  to  12    "     " 

Magnesium  oxide,  iron  oxide,  sodium  chloride,  sulphates,  and  potas- 
sium sul]3hocyanide  have  all  been  found  as  components  of  salivary  calculi. 

Calculi  composed  largely  of  uric  axiid  have  been  found  in  the  salivary 
ducts  of  individuals  suffering  from  the  uric-acid  diathesis. 

Varieties. — ^It  has  been  customary  among  the  earlier  writers  to  classify 
the  varieties  of  salivary  calculus,  or  tartar,  according  to  its  color  and 
density,  as  though  the  difference  in  these  respects  was  a  sufdcieut  ground 
for  designating  it  as  a  separate  variety. 

Salivary  calculus  varies  in  color  from  light  yellow  to  black,  and  be- 
tween these  extremes  it  may  present  any  shade  of  green  or  brown.  In 
physical  characteristics  it  may  be  soft  or  hard,  brittle  or  coherent,  but 
neither  of  these  features  or  characteristics  is  of  sufficient  importance, 
either  from  a  pathologic  or  a  clinic  stand-point,  to  form  the  foundation  of 
a  classification.     All  of  the  differences  in  color  may  be  readily  accounted 


DEPOSITS   UPON   THE   TEETH.  525 

for  by  the  fact  tliat  the  micro-organisms  of  the  mouth  are  capable,  through 
their  chromogenic  function,  of  imparting  to  the  deposits  any  shade  of 
these  colors  ;  while,  upon  the  other  hand,  the  ingestion  of  certain  kinds  of 
food  and  of  medicines  and  the  use  of  tobacco,  either  chewing  or  smoking, 
will  also  produce  a  change  in  the  color  of  the  concretions.  Smoking  pro- 
duces a  black  color  of  the  tartar,  but  time  and  the  action  of  the  micro- 
organisms will,  as  in  caries,  produce  similar  dark  colors. 

The  physical  characteristics  are  likewise  governed  by  the  element  of 
time.  Tartar  that  is  freshly  deposited  is  soft  and  yellowish-white  in  color, 
and  so  chalky  in  its  nature  that  the  slightest  effort  is  sufficient  to  dislodge 
it  in  bulk  ;  while  that  which  has  been  deposited  for  a  much  longer  time 
will  be  hard  and  brown  or  black  in  color,  and  require  considerable  force 
to  dislodge  it.  The  older  the  deposit  becomes  the  darker  will  be  its  color. 
Its  density,  brittleness,  and  coherent  qualities  are  also  dependent  upon  the 
element  of  time  for  these  characteristics. 

Salivary  calculus  is  formed  most  rapidly  in  a  saliva  which  gives  an 
alkaline  reaction ;  while  if  the  secretions  are  acid,  salivary  calculus  not 
only  does  not  forjn,  but  if  the  reaction  is  decidedly  acid,  the  tartar  already 
formed  upon  the  teeth  may  be  dissolved  and  removed. 

Clinically  there  are  three  forms  of  salivary  calculus  : 

1.  That  which  is  formed  upon  the  surfaces  of  the  crowns  of  the  teeth, 
— supergingival  deposits. 

2.  That  which  is  formed  in  isolated  islands,  or  as  a  narrow  band  at  the 
cervices  of  the  teeth,  beneath  the  margin  of  the  gums, — cervical  deposits. 

3.  That  which  is  formed  in  thin  scales  uj^on  the  sides  of  the  root  in 
open  pockets  more  or  less  remote  from  the  margins  of  the  gums, — subgin- 
gival deposits. 

The  first  variety,  or  supergingival  deposits,  of  salivary  calculus  is  found 
upon  the  crowns  of  the  teeth.  It  may  be  soft  and  friable  or  hard  and 
brittle,  according  to  the  length  of  time  which  has  been  consumed  in  form- 
ing the  deposit.  Its  color  is  usually  a  dirty  white  or  yellow,  but  it  may 
be  any  shade  of  green,  brown,  or  black,  according  to  the  length  of  time  it 
has  been  forming,  the  especial  chromogenic  bacteria  present  in  the  mouth, 
and  the  habits  of  the  individual.  This  variety  of  tartar  is  clinically  the 
most  common,  as  well  as  the  least  harmful.  It  frequently  accumulates  in 
great  quantities,  particularly  upon  those  teeth  which  are  directly  opjDosite 
the  salivary  ducts.  Sometimes  the  crowns  of  these  teeth  become  com- 
pletely covered  with  the  deposits,  so  that  the  semblance  of  the  tooth  is  lost. 
Figs.  616,  617,  618,  and  619  show  examples  of  such  cases. 

Teeth  which  stand  out  of  the  normal  line,  particularly  when  located 
inside  of  the  arch  and  in  the  lower  jaw,  are  most  often  covered  with  such 
deposits  ;  such  teeth  may  become  so  encrusted  with  the  calcic  material  as 
to  give  them  the  appearance  of  necrosed  and  denuded  bone.  Such  errors 
in  diagnosis  have  been  made,  and  serious  surgical  operations  undertaken 
for  the  relief  of  a  bone  disease,  which  might  have  been  prevented  by  count- 
ing the  teeth  upon  that  side  of  the  jaw  and  searching  for  the  missing  ones 
which  could  not  be  accounted  for  by  extraction  or  otherwise. 

The  writer  well  remembers  such  a  case,  in  which  he  was  acting  as  con- 


526  OPERATIVE   DENTISTEY. 

sultant.  The  tumor  was  situated  upon  the  left  side  of  the  lower  jaw,  upon 
the  floor  of  the  mouth,  in  the  region  of  the  second  bicuspid,  which  upon 
examination  was  found  missing.  All  of  the  other  teeth  were  in  normal 
position.  The  tumor  was  about  the  size  of  a  pecan-nut  and  had  the  ap- 
pearance of  necrosed  bone,  but  the  sensation  conveyed  by  scratching  it  with  a 
steel  instrument  was  so  different  from  that  of  dead  bone  that  the  writer  was 
led  to  believe  from  this  fact,  and  also  from  its  location,  which  was  directly 
beneath  where  the  missing  bicuspid  should  be,  that  the  tumor  was  nothing 
more  than  the  missing  tooth,  the  crown  of  which  was  encased  in  salivary 
calculus.  The  diagnosis  was  proved  by  splitting  the  calculus  with  a  chisel 
and  mallet,  when  the  halves  fell  apart,  exposing  the  crown  of  the  missing 
bicuspid  tooth. 

The  rapid  formation  of  salivary  calculus  is  indicative  of  a  disturbance 
in  the  equilibrium  of  the  metabolic  process  of  tissue  waste  and  repair,  or, 
in  other  words,  constructive  or  synthetic  metabolism  is  not  keeping  pace 
with  that  of  the  destructive  process.  The  breath  and  the  saliva  under  sach 
circumstances  have  a  foul  and  disgusting  odor.  The  odor  left  upon  the 
fingers  of  the  operator  when  they  have  been  in  contact  with  such  an  offen- 
sive saliva  is  very  disagreeable,  indeed,  and  often  requires  repeated  bathing 
in  antiseptic  and  deodorant  solutions  before  it  is  entirely  removed. 

The  greatest  care  should  be  exercised  in  sterilizing  the  hands  and  the 
instruments  used  in  the  treatment  of  such  cases,  as  the  saliva  is  loaded 
with  myriads  of  micro-organisms,  often  of  the  most  virulent  varieties. 

Salivary  calculus  of  the  Jirst  variety  often  presents  a  distinct  lamina- 
tion which  conforms  to  the  outline  of  the  surface  upon  which  it  was 
deposited. 

The  pathologic  effect  of  salivary  calculus  deposited  upon  the  crowns 
of  the  teeth  will  dex3end  upon  the  amount  and  the  locality  of  the  deposit. 
When  occurring  in  small  quantity  it  seems  to  be  entirely  harmless, — in  fact, 
it  seems  sometimes,  when  deposited  upon  a  tooth  with  a  carious  defect,  that 
it  retards  or  entirely  arrests  the  progress  of  the  caries ;  many  cases  have 
been  seen  in  which  the  carious  cavity  has  been  filled  with  salivary  calcu- 
lus and  the  disease  completely  arrested.  It  must  be  remembsred,  how- 
ever, that  the  conditions  which  favor  the  formation  of  salivary  calculus  do 
not  favor  the  progress  of  dental  caries.  An  alkaline  condition  of  the 
saliva  promotes  the  deposition  of  calcic  material  and  retards  dental  caries, 
while  an  acid  condition  of  the  salivary  secretions  favors  the  progress  of 
caries  and  retards  or  altogether  prevents  the  accumulation  of  salivary 
calculus. 

When  tartar  of  the  first  variety,  or  supergingival  deposit,  accumulates  in 
large  masses  and  impinges  upon  the  gums,  it  acts  as  a  mechanic  irritant, 
and  produces  ulceration  of  this  tissue,  resorption  of  the  alveolar  plate,  and 
recession  of  the  gums.  The  accumulations  may  be  so  extensive  in  certain 
localities  as  entirely  to, cover  the  teeth  and  to  unite  them  into  a  solid  mass. 
Such  accumulations  have  been  known  to  involve  the  six  anterior  inferior 
teeth  to  such  ati  extent  as  completely  to  destroy  their  attachment  to  the 
jaw  and  cause  them  to  be  exfoliated  like  a  mass  of  necrosed  bone. 

The  second  variety,   or  cervical  deposit  of  salivary  calculus,  is  found 


Fig.  616.— Salivary  calculus. 


Fig.  617.— Salivary  calculus. 


Fig.  61«. — Salivarv  calculus. 


Fig.  619.— Salivarv  calculus. 


Fig.  C20.— Glands  of  Serres.     X  50. 


DEPOSITS    UPON    THE   TEETH.  527 

upon  tlie  cervices  of  the  teeth  in  the  form  of  isolated  islands,  usually  upon 
the  lingual  surface  or  in  the  form  of  a  narrow  band  directly  beneath  the 
free  margins  of  the  gums.  It  is  generally  dark  green  or  brown  in  color, 
very  hard,  brittle,  and  tenacious,  requiring  in  some  instances  considerable 
force  to  dislodge  it.  This  variety  of  calculus  is  most  often  found  in  the 
mouths  of  robust  individuals,  in  those  who  live  high,  and  those  with 
rheumatic  and  gouty  tendencies. 

The  pathologic  effect  of  this  variety  of  calculus  is  to  establish  a  low 
grade  of  chronic  inflammation  of  the  gums,  ulceration  of  the  gingival  mar- 
gins, resorption  or  necrosis  of  the  margins  of  the  alveoli,  and  recession  of 
the  gums.  These  conditions  are  the  result  of  the  mechanic  irritation  pro- 
duced by  the  impingement  of  the  calculus  upon  the  margins  of  the  gums 
and  the  pericementum. 

Acute  inflammatory  symptoms  are  rarely  presented  in  this  form  of 
salivary  calculus  unless  some  traumatic  injury  has  occurred  to  severely 
lacerate  the  gums,  as  by  an  unusual,'  vigorous  use  of  the  toothbrush  or 
masticating  hard  substances.  Such  an  inflammation  may  sometimes  be- 
come degenerative  and  involve  the  gums  of  both  jaws  and  extend  to  the 
hard  palate,  producing  an  obstinate  ulcerative  stomatitis. 

The  presence  of  these  concretions  rarely  produces  a  diffuse  inflamma- 
tion of  the  pericementum.  The  inflammation  is  usually  confined  to  that 
location  which  is  the  direct  seat  of  the  irritation, — viz.,  the  margins  of  the 
gum  and  the  pericementum.  These  tissues  are  gradually  destroyed  by  the 
encroachment  of  the  deposit  and  the  consequent  inflammation  and  ulcera- 
tion produced  by  their  presence. 

This  variety  of  salivary  deposit  seems  to  accumulate  most  rapidly  after 
a  chronic  inflammatory  process  has  been  established  in  the  free  margins  of 
the  gums.  This  led  Serres  and  some  other  pathologists  to  the  supposition 
that  the  glandular  structures  of  the  gums  (glands  of  Serres,  Fig.  620) 
were  instrumental  in  causing  the  formation  of  the  deposits.  This  ques- 
tion has,  however,  not  been  satisfactorily  settled.  The  general  opinion 
seems  to  be,  however,  that  the  deposits  come  directly  from  the  salivary 
secretions,  and  that  the  inflammatory  conditions  of  the  gingivae  resulting 
from  the  mechanic  irritation  present  in  some  way — perhaps  through  cer- 
tain products  of  the  decomposition  of  tissue,  NH3  and  H^S — more  favorable 
conditions  for  the  deposition  of  the  calcic  material  found  in  the  saliva  than 
would  be  the  case  under  other  circumstances,  hence  its  more  rapid  accu- 
mulation. 

The  third  variety,  or  subgingival  deposit,  is  that  which  is  found  in  thin 
scales  upon  the  sides  of  the  roots  of  the  teeth  in  open  pockets  more  or  less 
remote  from  the  free  margins  of  the  gums.  This  form  of  deposit  and  its 
effect  upon  the  pericementum  and  the  surrounding  tissues  will  be  dis- 
cussed in  the  chapter  on  pyorrhoea  alveolaris. 

Treatment.— -The  treatment  of  the  supergingival  deposits,  or  ordinary 
•  form  of  salivary  calculus,  and  of  the  cervical  variety  consists  in  removing 
the  concretions  from  the  surfaces  of  the  teeth  by  the  aid  of  various  instru- 
ments known  as  scalers.     These  instruments  are  made  with  suitable  curves 
and  angles  adapted  to  reach  every  portion  of  the  various  surfaces  of  the 


528 


OPERATIVE   DENTISTRY. 


tooth-crown,  while  the  blades  are  of  such  form  and  temper  that  the  edges 
can  be  kept  sharp.  Fig.  621  illustrates  a  few  of  the  most  useful  shapes 
employed  for  this  operation.     Some  of  these  instruments  are  intended  to 


Fig.  621. 


Small  scalers. 

be  used  as  chisels,  others  as  hoes  or  scrapers.  The  operation  consists  of 
first  scaling  or  scraping  away  the  accumulated  mass  of  tartar,  and  after- 
wards thoroughly  polishing  the  exposed  surfaces  of  the  teeth  with  pulver- 
ized pumice.     This  part  of  the  operation  may  be  done  with  any  orange- 

FiG.  622. 


wood  wedge-stick  flattened  at  one  end  or  by  variously  shaped  rubber  disks, 
wheels,  and  cups,  or  with  small  brushes,  as  shown  in  Figs.  622  and  623, 
used  in  the. dental  engine. 

Fig.  623. 


After  the  concretions  have  all  been  removed,  the  mouth  should  be 
thoroughly  irrigated  with  a  soothing  antiseptic  mouth- wash,  like  listerine, 
pasteurine,  borolyptol,    etc.,    followed  by   the  spray  from  an   atomizer 


DEPOSITS    UPON    THE    TEETH.  529 

charged  with  the  same  solution,  which  should  be  directed  into  the  inter- 
dental spaces  to  make  sure  that  all  loose  particles  of  tartar  are  removed 
from  between  the  teeth  and  from  beneath  the  margins  of  the  gums. 
Finally,  to  relieve  any  inflammation  that  may  be  present  and  to  promote 
the  healing  of  the  gums,  they  may  be  painted  with  a  combination  of  the 
tinctures  of  iodine  and  aconite  in  equal  parts. 

The  prevention  of  the  further  accumulation  of  salivary  calculus  will 
depend  largely  upon  the  time  which  the  individual  is  willing  to  give  to  the 
cleansing  of  the  teeth.  Thorough  brushing  of  the  teeth  after  each  meal 
with  a  suitable  dentifrice  and  the  judicious  use  of  floss-silk  and  tooth-picks 
will  usually  prevent  the  further  accumulation  of  deposits  upon  all  accessi- 
ble surfaces.  The  prevention,  therefore,  of  the  accumulation  of  salivary 
deposits  sums  itself  up  into  the  question  of  cleanliness.  Many  refined 
people  who  are  extremely  neat  in  every  other  respect  often  present  mouths 
which  are  positively  disgusting  to  behold,  but  whose  sense  of  refinement 
would  be  greatly  shocked  if  they  were  told  that  their  mouths  and  teeth 
were  in  a  very  filthy  condition,  and  that  they  carried  about  in  their  oral 
cavities  conditions  which  were  more  fatal  to  good  health  than  the  presence 
of  sewer  gas  in  their  dwellings. 


34 


CHAPTEE    XXXVIIL 

PYOEEHCEA   ALVEOLARTS. 

Definition. — Pj^orrhoea  (Greek  -nbov^  pus ;  poia,  a  flow).  A  purulent 
discharge.  Alveolaris  (Latin,  a  small  hollow).  Pertaining  to  the  alveoli, 
or  the  sockets  of  the  teeth.  The  term,  therefore,  means  a  flow  of  pus  from 
the  alveolus  of  a  tooth.  But  as  this  is  a  symptom  of  several  other  diseases 
which  involve  the  same  tissues, — viz.,  alveolar  abscess,  traumatic  perice- 
mentitis, scorbutic  pericementitis,  mercurial  pericementitis,  etc., — the  term 
does  not  seem  to  be  well  selected  to  express  the  characteristic  pathologic 
features  of  the  disease.  The  term  pyorrhoea  alveolaris  has,  however,  been 
quite  generally  adopted  by  the  profession,  and  for  that  reason  it  is  perhaps 
better  to  retain  it,  although  several  others  have  been  suggested  which  are 
more  appropriate,  as  they  convey  a  better  idea  of  the  true  nature  of  the 
disease. 

Synonymes. — Riggs's  disease,  suppuration  conjointe,  pyorrhoea  inter- 
alveolar- dentaire,  gingivitis  expulsiva,  osteo-periostiti-alveolo-dentaire, 
pyorrhoea  alveolo,  caries  alveolaire  specifica,  cemen to  periostitis,  infectoso- 
alveolitis,  periostitis  dentalis,  periostitis-alveolo-dentalis,  calcic  pericemen- 
titis, phagedenic  i^ericementitis,  gouty  pericementitis,  ptyalogenic  calcic 
pericementitis,  hsematogenic  calcic  pericementitis,  blennorrhoea  alveolaris, 
interstitial  gingivitis. 

The  various  terms  or  synonymes  which  have  been  applied  to  this  affec- 
tion express  in  a  certain  sense  the  views  held  by  the  writers  who  have  sug- 
gested them,  as  to  the  nature  of  the  disease. 

Pyorrhoea  alveolaris  is  a  disease  ^hioh primarily  affects  t\iQ pericertientum, 
manifesting  itself  in  a  suppurative  inflammation,  sometimes  acute  in  form, 
but  generally  of  a  chronic  type  ;  and,  secondarily,  the  inflammatory  process 
involves  the  walls  of  the  alveolus  and  the  gum.  This  process  is  accompanied 
by  loosening  and  turning  or  extrusion  of  the  teeth,  a  discharge  of  pus  from 
the  alveolus,  gradual  disintegration  of  the  alveolar  process  (caries),  reces- 
sion of  the  gums,  and  finally  the  tooth  loses  its  alveolar  and  gingival 
connection  and  falls  out. 

Upon  the  loss  of  the  tooth  the  inflammatory  symptoms  immediately 
subside,  which  proves  conclusively  that  the  local  manifestations  of  the 
disease  are  primarily  associated  with  the  dental  tissues,  and  not  with  the 
gingivae  or  the  alveolar  processes. 

Witzel  and  others  have  maintained,  however,  that  the  disease  was 
primarily  located  in  the  alveolar  border,  and  that  the  gum  and  pericemen- 
tum were  involved  as  a  secondary  feature  of  the  disease. 

Pyorrhoea  alveolaris,  next  to  the  subject  of  dental  caries,  has  attracted 

more  attention  from  dental  surgeons  than  any  other  affection  of  the  human 

mouth.     It  has  been  thought  to  be  a  disease  of  modern  origin  and  a  result 

of  the  sins  of  our  modern  civilization  ;  but  a  visit  to  the  ethnologic  depart- 

530 


,  PYOEEHCEA   ALVEOLARLS.  531 

ments  of  our  large  museums  will  convince  any  one  that  the  disease  is  not 
confined  to  modern  times  nor  to  higher  civilization,  but  that  in  all  prob- 
ability it  is  as  old  as  the  human  race.  Evidences  of  the  disease  are  to  be 
seen  alike  in  ancient  and  modern  skulls,  in  the  skulls  of  aboriginal  tribes, 
and  also  in  those  of  barbarous,  semi- civilized,  and  civilized  nations.  On 
the  other  hand,  however,  there  seems  to  be  some  reason  for  believing  the 
disease  to  be  on  the  increase  among  civilized  nations  of  the  present  day. 
Whether  this  is  a  fact  or  not  remains  yet  to  be  proven.  Statistics  are 
necessary  to  establish  such  a  fact,  and  these  have  not  been  gathered.  This 
statement,  however,  seems  quite  true, — viz.,  the  dental  surgeon  is  called 
upon  to  treat  more  and  more  of  these  cases  every  year.  Perhaps  this  is 
due  to  his  better  general  knowledge  of  the  disease,  and  to  his  ability  to 
recognize  its  clinic  aspects  and  manifestations  not  only  in  the  fully 
developed  disease  but  in  its  incipient  stages ;  or  it  may  be  possible  that 
the  disease  is  sometimes  confounded  with  other  affections  which  present 
somewhat  similar  symptoms  and  pathologic  features.  It  is  no  uncommon 
thing  for  a  chronic  alveolar  abscess  which  is  discharging  through  the 
alveolus  to  be  mistaken  in  a  hasty  examination  for  a  case  of  pyorrhoea 
alveolaris,  and  vice  versa.  It  therefore  becomes  exceedingly  important  that 
every  examination  should  be  made  with  the  utmost  care  and  precision, 
that  errors  in  diagnosis  may  be  avoided. 

Causes. — A  wide  difference  of  opinion  exists  among  pathologists  and 
dental  practitioners  in  reference  to  the  etiology  of  this  disease.  So  much 
interest  has  been  taken  in  the  study  of  this  subject  in  recent  years  that 
the  literature  upon  the  etiology  of  the  disease  has  become  quite  voluminous, 
and  nearly  -as  confusing.  The  writer  has  found,  however,  that  after  a 
careful  review  of  the  literature  these  opinions  can  all  be  grouped  under 
three  heads : 

1.  That  the  disease  originates  in  some  constitutional  state  or  dyscrasia. 

2.  That  the  disease  is  caused  entirely  by  local  irritation  and  environment. 

3.  That  the  disease  is  due  to  the  infection  of  the  tissues  with  micro-organ- 
isms. 

Constitutional  Origin  of  the  Disease. — Fanchard  (1746)*  was  the 
first  to  call  attention  to  the  disease  and  record  its  essential  clinical  features, 
but  offered  no  opinion  as  to  the  origin  of  the  disease,  neither  did  he  desig- 
nate it  by  any  specific  term. 

Jourdain  (1778)  f  published  a  communication  describing  the  disease, 
and  made  the  suggestion  that  it  was  of  scorbutic  origin,  and  termed  it  in 
its  later  stages  ^^  conjoined  suppuration,''^  because  it  is  then  complicated  with 
a  purulent  discharge  from  between  the  margins  of  the  gums  and  the 
cervices  of  the  teeth  and  a  gradual  destruction  of  the  alveolar  processes. 

Toirac  (1822),  J  in  his  communication  upon  the  disease,  termed  it 
^^pyorrhoea-inter-alveolo-dentaire,"  but  failed  to  offer  an  opinion  upon  the 
oriffin  of  the  disease. 


*  Independent  Dental  Journal,  1875. 

t  Philadelphia  Journal  of  Medical  and  Physical  Sciences,  1821. 

X  Journal  of  the  American  Medical  Association,  1879. 


532  OPEEATIVE    DENTISTRY. 

Bell  (1829)*  described  the  disease  in  all  of  its  clinical  features,  and 
divided  the  affection  into  two  distinct  forms,  one  dependent  upon  the 
formation  of  deposits  upon  the  teeth,  the  other  caused  by  a  constitutional 
condition  which  may  be  looked  upon  as  a  sort  of  premature  old  age.  He 
says,  ''In  forming  a  judgment  upon  cases  of  this  description,  however, 
and  even  upon  those  in  which  the  loss  of  substance  is  associated  with  more 
or  less  of  diseased  action,  it  is  necessary  to  recollect  that  the  teeth  are 
generally  removed  in  old  age  by  this  identical  mode, — namely,  the  de- 
struction of  their  support  by  the  absorption  of  the  gums  and  the  alveolar 
processes ;  and  as  this  step  towards  general  decay  commences  at  very 
different  periods  in  different  constitutions,  it  may  doubtless  in  many  cases, 
even  in  persons  not  past  the  middle  period  of  life,  be  considered  as  an  in- 
dication of  a  sort  of  premature  old  age,  or  an  anticipation,  at  least,  of 
senile  decay,  as  far  as  regards  these  parts  of  the  body." 

Harris  (1853)  f  termed  the  disease  a  "  chronic  inflammation  of  the  gums,^' 
dependent  upon  morbid  constitutional  conditions  as  predisposing  causes, 
such  as  ' '  bilious  and  inflammatory  fevers,  the  excessive  use  of  mercurial 
medicines,  the  venereal  virus,  intemperance,  and  debauchery ;  while  any 
deterioration  of  the  fluids  of  the  body  is  peculiarly  conducive  to  it.  Per- 
sons of  cachectic  habit  are  far  more  subject  to  it,  and  generally  in  the  worst 
forms,  than  those  individuals  in  the  enjoyment  of  good  health."  As  im- 
mediate or  exciting  causes  he  mentions  the  "local  irritation  of  salivary 
calculus,  carious,  dead,  loose,  or  aching  teeth  or  roots  of  teeth,  or  teeth 
which  occupy  a  wrong  position  or  that  are  crowded  in  their  arrangement." 

Marechal  de  Calvi  (1860)  ;|:  looked  upon  the  disease  as  an  hereditary 
constitutional  disorder,  and  termed  it  gingivitis  expulsiva. 

Magitot  (1867),  §  in  his  admirable  paper  upon  the  nature  of  the  dis- 
ease, describes  it  as  a  slow  but  progressive  inflammation  causing  the 
destruction  of  the  periosteal  membrane  and  the  cementum,  which  begins 
at  the  cervix  and  extends  to  the  apex  of  the  root,  and  involves  the  loss 
of  the  tooth.  The  term  by  which  he  designated  the  disease  was  ' '  osteo- 
periostiti-alveolo-dentaire,"  as  this  was  the  exact  seat  of  the  disease.  He 
believed  the  disease  was  primarily  located  in  the  j)ericementum,  and  that 
soon  after  the  apxjearance  of  the  inflammation  in  the  membrane  the  gums 
and  osseous  walls  of  the  alveolus  became  involved,  but  that  the  disease 
was  never  primarily  located  in  those  latter  tissues. 

He  viewed  the  causes  of  this  peculiar  inflammation  as  very  complex. 
In  his  opinion  the  origin  of  the  disease  lay  in  a  faulty  general  nutrition. 
Persons  of  a  gouty  and  rheumatic  diathesis  furnished  the  greatest  number 
of  cases,  but  it  was  also  very  common  in  individuals  suffering  from  dia- 
betes mellitus,  albuminuria,  and  ansemia. 

The  formation  of  calcic  deposits  upon  the  teeth  he  regarded  as  purely 
accidental  and  playing  no  important  part  in  the  etiology  of  the  disease.     He 


*  Anatomy,  Physiology,  and  Diseases  of  the  Teeth, 
t  Dental  Surgery. 

X  Journal  of  the  American  Medical  Association,  1897. 
?  Etudes  et  Experiences  sur  la  Salive,  Paris. 


PYORRHOEA   ALVEOLARIS.  533 

advised,  however,  as  an  indispensable  preliminary  to  any  form  of  treat- 
ment, the  thorougli  removal  of  all  concretions  upon  the  roots  of  the  teeth. 

Wedl  (1870),*  in  describing  the  disease,  says,  ''That  portion  of  the 
root-membrane  which  is  in  relation  with  the  submucous  connective  tissue 
of  the  gums  appears  to  be  attacked  secondarily  in  most  cases,  in  conse- 
quence of  the  extension  of  the  disease,  either  from  the  enclosed  extremity 
of  the  root-membrane  or  from  the  inflamed  gums.  In  these  cases  the  gum 
becomes  detached  from  the  neck  of  the  tooth,  and  pressure  upon  the 
alveolus  forces  out  a  puriform  fluid.  This  condition  results,  without 
notable  pain,  in  the  loss  of  the  affected  tooth."  In  reference  to  the 
causation  of  the  disease  he  says,  "In  these  cases,  then,  we  have  to  do, 
first  of  all,  with  a  catarrhal  inflammation  of  the  gum,  which  afterwards 
extends  to  the  root- membrane." 

Brown  (1870)  f  was  the  first  to  suggest  that  the  disorder  was  due  to  the 
formation  of  certain  deposits  upon  the  roots  of  the  teeth,  which  were 
derived  from  the  serum  of  the  blood,  and  which  he  denominated  serumal 
calculus. 

Salter  (1875)  J  denominates  the  disease  "false  scurvy,^ ^  and  believes  it  is 
more  or  less  the  manifestation  of  constitutional  vice,  being  frequently 
associated  with  chronic  dyspepsia  and  general  ill-health,  'and  as  a  result  in 
females  of  frequent  pregnancies.  Certain  drugs,  like  mercury  and  iodide 
of  potassium,  when  given  to  excess  have  the  power  of  producing  the 
disease. 

Sirlette  (1876),  §  in  discussing  the  etiology  and  pathology  of  this  dis- 
order, stated  that  he  regarded  the  disease  as  due  to  certain  constitutional 
conditions,  such  as  rheumatism,  scrofula,  syphilis,  diabetes'  mellitus,  albu- 
minuria, etc.,  but  that  certain  local  conditions  acted  as  exoitiag  factors. 
He  denominated  the  affection  ''periostitis-alveolo-dentalis." 

Taft  (1876)  1 1  regarded  pyorrhoea  alveolaris  as  arising  from  a  general 
disorder  of  health,  and  unless  the  general  state  of  the  health  was  improved, 
local  treatment  would  be  of  no  avail. 

Eehwinkle  (1877),^  in  a  paper  upon  the  "Causes  and  Treatment  of 
Pyorrhoea  Alveolaris, ' '  says  the  origin  of  the  disease  can  often  be  traced  to 
the  action  of  mercury,  and  in  other  cases  to  constitutional  and  inherited 
predisposition,  while  it  often  exists  independently  of  foreign  deposits  and 
in  the  cleanest  of  mouths. 

Davis  (1879),**  in  a  paper  on  "Gum  and  Alveolar  Diseases,"  says  he  is 
unable  to  account  for  the  phenomena  of  Eiggs's  disease,  except  upon  the 
hypothesis  of  atrophy  of  the  peridental  membrane  or  of  the  external  fibrous 
covering  of  the  alveolus,  while  the  deposits  which  are  found  upon  the 
roots  of  the  teeth  are  an  accidental  sequence,  and  not  a  cause  of  the  disease. 

*  Pathology  of  the  Teeth, 
t  American  Journal  of  Dental  Science. 
X  Dental  Pathology  and.  Surgery. 
§  Gazzetta  Medica  di  Eoma,  1876. 
II  Operative  Dentistry. 
Tf  Dental  Cosmos  vol.  xix. 
**  Ibid. 


534  OPERATIVE    DENTISTRY. 

Cowles  (1879),*  in  a  discussion  upon  the  subject  of  "Eiggs's  Disease," 
said,  "Wedging  is  a  great  producer  of  this  difaculty,  and  therefore  I  am 
opposed  to  wedging,  but  a  more  general  cause  than  all  others  is  the  lack 
of  nutrition  in  the  parts." 

Bssig  (1879)  t  expressed  the  opinion  that  the  primary  cause  was  prob- 
ably systemic  ;  that  it  usually  makes  its  appearance  in  mouths  which  were 
remarkable  for  an  almost  complete  immunity  from  dental  caries  ;  and  this 
fact  has  led  to  the  assumption  that  such  evident  power  of  resisting  the 
usual  causes  of  decay  until  middle  life  implies  extreme  density  and  low 
degree  of  vitality  in  the  structure  of  the  teeth,  resulting  in  a  final  sever- 
ance between  them  and  the  more  highly  vitalized  contiguous  parts,  thus 
constituting  a  x)redisposing  cause  of  a  disease  liable  to  be  developed  by  an 
accretion  of  calculus  or  other  excitant.  The  disorder,  he  thinks,  is  a  local 
manifestation  of  a  constitutional  cause,  and  the  calcareous  deposit  merely 
an  accident  of  opportunity. 

Serran  (1880)  J  believed  that  the  primary  manifestation  was  a  local  con- 
gestion of  the  gums,  followed  by  an  inflammatory  exudation  in  the  peri- 
dental membrane,  loss  of  vitality  in  the  structure,  the  formation  of  pus, 
and  all  of  the  other  symptoms  and  pathologic  features  which  are  charac- 
teristic of  the  disorder.  He  recognized  the  fact,  however,  that  the  disease 
was  most  common  in  the  middle  period  of  life,  and  that  individuals  suffer- 
ing from  gout,  rheumatism,  diabetes  mellitus,  and  albuminuria  furnished 
the  principal  number  of  cases.  These  statements  were  in  certain  respects 
in  opposition  to  the  views  expressed  by  Magitot  in  1867  relative  to  the 
tissues  which  were  primarily  involved  in  the  disease. 

A  commission  appointed  by  the  Societe  de  Chirurgie  to  consider  the 
statements  of  Serran  denied  the  gingival  origin  of  the  disease,  and  sub- 
stantially upheld  the  views  of  Magitot. 

Mills  (1880)  §  claimed  that  the  cause  was  systemic,  and  the  deposit  only 
a  local  manifestation.  He  believed,  also,  that  age  was  not  the  only  factor 
in  the  production  of  the  disease,  but  that  various  influences,  physical  and 
mental,  were  often  powerful  abettors  of  the  disease.  Conditions  of  ner- 
vous exhaustion  may  exist  at  certain  periods  of  life,  permitting  the  local 
expression  of  a  disease  which  altered  circumstances  in  after-life  may  radi- 
cally modify.  In  his  opinion  the  disease  not  infrequently  appeared  in  the 
mouths  of  youths,  generally  as  a  sequence  of  one  of  the  eruptive  fevers. 

Atkinson  (1881)  ||  was  of  the  oj)inion  that  the  disease  was  of  consti- 
tutional origin,  the  result  of  nervous  debility  or  original  defective  innerva- 
tion, and  the  deposit  a  sequence  of  the  disorder,  but  never  the  cause. 

Coles  (1881)  ^  was  of  the  opinion  that  certain  systemic  conditions  acted 
as  predisposing  causes,  and  micro-organisms  as  local  exciting  causes. 

Ingersoll  (1881),**  in  a  paper  upon  "Sanguinary  Calculus,"  maintained 

*  Dental  Cosmos,  vol.  xxi. 

t  Ibid.,  vols,  xxii.,  xxiii. 
'  t  Bulletins  et  Memoires  de  la  Societe  de  Chirurgie,  tome  vi.  p.  411. 

§  Dental  Cosmos,  vol.  xxiii.  •  ||  Ibid. 

If  International  Medical  Congress,  1881. 
**  Ohio  Dental  Journal,  1881. 


PYORRHCEA    ALVEOLARIS.  535 

that  certain  concretions  were  formed  upon  the  roots  of  teeth  which  could 
not  be  derived  from  the  saliva,  as  they  were  formed  near  the  apex  of  the 
root,  and  under  circumstances  which  made  it  impossible  that  they  could 
be  of  salivary  origin.  This  form  of  calculus  contained  a  dark  coloring 
matter,  and  was  always  found  in  connection  with  ulceration  and  a  discharge 
of  pus.  The  liquor  sanguinis  contained  the  lime-salts  in  solution,  and  these 
were  crystallized  and  deposited  upon  the  roots  of  the  teeth. 

As  this  form  of  concretion  could  not  have  come  from  the  saliva,  he  con- 
cluded that  it  must  have  come  from  the  blood,  and  he  therefore  termed  it 
sanguinary  calculus. 

This  opinion  is  very  similar  to  that  expressed  by  Brown  in  1870,  which 
has  already  been  quoted. 

Eawls  (1885)  *  believed  the  causes  were  primarily  of  systemic  origin, 
as  expressed  in  inherited  and  acquired  tendencies,  habits,  and  environ- 
ment. Malarial  fever,  mercurial  ptyalism,  etc. ,  and  the  excessive  use  of 
sodium  chloride  were  all  important  factors  in  the  production  of  the  disease. 

Eeese  (1886)  f  was  of  the  opinion  that  the  disease  was  due  to  the  pres- 
ence of  the  uric  acid  diathesis  resulting  from  the  abuse  of  alcoholic  stimu- 
lants. 

Patterson  (1886)  %  revived  the  theory  of  Wedl  that  the  disease  was  due 
to  a  catarrhal  condition  of  the  oral  mucous  membrane  and  the  gingivae 
(oral  catarrh).  Patterson  also  believed  that  pyorrhoea  alveolaris,  like 
catarrh,  was  contagious,  and  sometimes  even  epidemic. 

Farrar  (1886)  §  looked  upon  the  disease  as  being  the  result  of  a  combi- 
nation of  systemic  conditions  and  tendencies  and  local  irritants,  and  held 
that  there  was  a  peculiar  systemic  condition  associated  with  hypersecretion 
and  an  increased  amount  of  earthy  deposits. 

Starr  (1886)  1 1  regarded  the  disease  as  due  to  certain  systemic  conditions 
and  tendencies,  and  associated  with  some  undetermined  local  irritating 
factor.  He  was  of  the  opinion  that  this  local  factor  was  the  same  as  that 
which  caused  hypercementosis.  He  also  stated  that  in  his  experience  a 
majority  of  the  teeth  affected  with  pyorrhoea  alveolaris  were  found  in  the 
upper  jaw. 

Sudduth  (1887)^  expressed  the  opinion  that  pyorrhoea  alveolaris  was  a 
sequel,  or  rather  the  secondary  stage,  of  a  disease  which  had  its  inception 
in  a  catarrhal  stomatitis.  In  fact,  he  thinks  he  is  justified  in  classing  the 
disease  as  a  localized  catarrhal  stomatitis  which  is  dependent  upon  hered- 
itary dyscrasia  for  its  constitutional  factor.  The  disease  may  be  either 
acute  or  chronic. 

Sutton  (1887)  **  regards  the  disease  as  undoubtedly  of  constitutional 
origin,  as  expressed  in  gout,  rheumatism,  mollities  ossiura,  and  other 
wasting  diseases. 

*  Dental  Cosmos,  vol.  xxvii. 

t  Transactions  of  the  Louisiana  State  Dental  Society,  1886. 
%  Dental  Cosmos,  vol.  xxvii. 

§  Independent  Practitioner,  vol.  vii.  ||  Ibid. 

\  Sajous's  Annual,  1888,  vol.  iii. 
**  Dental  Record,  1887. 


636  OPERATIVE   DENTISTRY. 

Marshall  (1891)  *  expressed  the  opinion  that  in  many  cases  the  origin 
of  the  disease  could  be  traced  to  the  rheumatic  and  gouty  diathesis,  and 
that  the  deposition  of  the  concretions  upon  the  roots  of  the  teeth  in  those 
localities  not  easily  reached  by  the  saliva,  or  in  which  the  presence  of  the 
saliva  would  be  an  impossibility,  is  due  to  the  same  cause  which  produces 
the  chalky  formations  found  in  the  joints  and  fibrous  tissue  of  gouty  and 
rheumatic  individuals,  and  suggested  that  these  deposits  were  formed  of 
urates  of  lime  and  soda. 

Pierce  (1892,  1894,  and  1895)  f  in  a  series  of  papers  presented  a  num- 
ber of  clinic  and  pathologic  facts  which  in  their  totality  seemed  to  estab- 
lish the  kinship  between  pyorrhoea  alveolaris,  or  hematogenic  calcic  peri- 
cementitis, and  the  systemic  condition  generally  recognized  as  the  gouty  or 
uric  acid  diathesis. 

Darby  (1894)  X  strongly  upheld  the  theory  of  the  constitutional  origin 
of  the  disorder,  and  ascribed  it  to  the  uric  acid  diathesis. 

Burchard  (1895)  §  believed  the  disease  to  be  due  to  constitutional  and 
local  predisposing  causes  and  to  local  exciting  causes.  Among  the  consti- 
tutional predisposing  causes  he  mentions  hereditary  influences,  particu- 
larly arthritic  diseases  and  the  diseases  of  suboxidation  and  faulty  elimina- 
tion ;  among  the  local  predisposing  causes  are  overuse,  disuse,  and  misuse 
of  the  teeth.  These  also  often  act  as  direct  exciting  causes.  Subgingival 
deposits  also  act  as  exciting  causes. 

0.  H.  Tomes  (1897)  1 1  regards  the  causes  and  pathology  of  the  disease 
as  very  obscure.  There  is  much  to  support  the  idea  tliat  a  constitutional 
cause  is  at  the  bottom  of  it, — for  instance,  it  usually  occurs  with  some  near 
approach  to  bilateral  symmetry,  and  the  teeth  first  affected  are  often  not 
those  most  liable  to  the  deposit  of  tartar, — while  he  assigns  to  tartar  a 
merely  secondary  influence  in  the  progress  of  the  disease  which  comes  into 
ojDeration  only  after  the  mischief  has  begun. 

He  does  not,  however,  subscribe  to  the  uric  acid  theory. 

Harlan  (1898)  ^  regarded  the  disease  as  being  largely  influenced  by 
heredity  and  acquired  conditions,  deposits  acting  as  exciting  causes. 

Ehein  (1899)  **  divides  the  disease  into  pyorrhcea  simplex  and  pyorrhoea 
complex.  The  former  he  believes  is  caused  entirely  by  local  irritants,  the 
latter  by  constitutional  conditions,  such  as  malnutrition,  improper  elimi- 
nation, uric  acid  diathesis,  etc. 

Kirk  (1899),  ft  recognizing  the  constitutional  origin  of  the  disease,  says, 
^'It  is  to  the  class  of  non-bacterial  inflammatory  tissue  reactions  that 
phagedenic  pericementitis  in  its  earlier  stages  belongs,  and  that  the  toxic 
irritant  is  the  group  of  alloxuric  bodies  which,  like  their  congener  uric 

*  Transactions  of  the  American  Medical  Association,  1891. 

t  International  Dental  Journal,  vols,  xiii.,  xv.,  xvi. 

X  Ibid.,  vol.  XV. 

§  Dental  Pathology,  Therapeutics,  etc. 

II  Dental  Surgery. 

\  Dental  Cosmos,  vol.  xl. 
**  Dental  Review,  1899. 
tt  International  Dental  Journal^  vol.  xx. 


PYORRHCEA   ALVEOLARIS.  537 

acid,  are  waste  products  of  nitrogenous  metabolism,  and  as  a  result  of 
improper  elimination  find  their  way  into  the  blood-stream  and  thence  to 
the  membranous  investment  of  the  tooth,  that  are  the  active  causes  of  de- 
generation of  the  tissue  in  question,  and,  should  the  irritative  influence  be 
of  sufficient  intensity  as  related  to  the  vital  resistance  of  the  elements  of 
the  membrane,  may  and  do  cause  its  molecular  necrosis  with  attendant 
inflammatory  reaction." 

Fitzgerald  (1899)  *  claimed  that  the  production  of  pyorrhoea  alveolaris 
depended  upon  a  constitutional  predisposing  cause  and  an  exciting  cause 
in  the  form  of  a  local  irritation.  The  predisposing  cause  might  be  tuber- 
culosis, syphilis,  scurvy,  the  exhaustion  following  acute  infectious  diseases 
or  any  other  source  of  maluurition.  The  exciting  cause  is  usually  a  gin- 
givitis induced  by  several  forms  of  local  irritation.  He  also  recognized  a 
gouty  origin  of  the  disease  in  which  the  local  necrosis  of  the  pericementum 
is  caused  by  gouty  disease  of  one  of  the  blood-vessels  in  its  substance. 

Talbot  (1899)  f  terms  the  disease  interstitial  gingivitis,  and  says  the  causes 
are  divisible  into  predisposing  and  exciting,  the  predisposing  causes  being 
again  subdivided  into  local  and  constitutional.  As  predisposing  factors  of 
the  disease  he  mentions  conditions  of  jaw  evolution,  the  transitory  nature 
of  certain  structures,  degeneracy,  and  conditions  of  previous  irritation  and 
inflammation.  The  exciting  causes  are  either  constitutional  or  local,  but, 
as  a  rule,  are  local  or  have  a  local  action.  He  thinks  calcic  deposits  are  a 
result  and  not  a  cause  of  the  disease. 

Local  Origin  of  the  Disease. — Koecker  (1821)  |  regarded  the  dis- 
ease, which  he  called  inflammation  of  the  gums,  as  one  of  local  origin,  and 
caused  by  the  irritating  effects  of  tartar.  He  said,  ^'In  all  the  various 
forms  of  the  affection  which  he  had  observed  he  had  never  seen  a  case  in 
which  tartar  was  not  present.  .  .  .  Persons  of  robust  constitution  are 
much  more  liable  to  this  affection  of  the  gums  than  those  of  delicate 
habit,  and  it  shows  itself  in  its  worst  form  after  the  age  of  thirty  offcener 
than  at  any  earlier  period." 

Bromwill  (1867)  §  was  of  the  opinion  that  the  cause  of  the  disease  was 
a  local  one,  due  to  the  thinness  of  the  alveolar  process  between  the  teeth, 
which  deprived  the  peridental  membrane  and  the  gum  of  proper  support. 
Malocclusion  of  the  teeth  also  exerted  an  influence  by  establishing  inflam- 
mation. 

Eiggs  (1875)  1 1  was  very  emphatic  in  his  opinion  that  the  disorder  was 
due  entirely  to  the  local  irritation  of  salivary  calculus,  which  was  deposited 
at  the  necks  of  the  teeth  just  beneath  the  free  margin  of  the  gum,  and 
extended  from  there  towards  the  apex  of  the  root,  causing  inflammation  of 
the  gum  and  peridental  membrane,  necrosis  of  the  edge  of  the  alveolus,  a 
discharge  of  pus,  and  recession  of  the  gums. 


*  Clinical  Journal,  March,  1899. 

t  Interstitial  Gingivitis,  1899. 

X  Principles  of  Dental  Surgery. 

§  Dental  Cosmos,  vol.  xxiv. 

II  Transactions  of  the  American  Academy,  1875. 


538  OPERATIVE    DENTISTRY. 

Sliieff  (1875),*of  Vienna,  was  of  the  opinion  that  the  disease  had  its 
apparent  origin  in  local  irritants  induced  by  mechanic,  chemic,  and 
thermic  changes.  The  real  origin  of  the  disease,  however,  was  often  very 
obscure.     The  influence  of  the  rheumatic  diathesis  was  doubtful. 

Niles  (1880)  f  supported  the  theory  that  salivary  calculus  was  the  pri- 
mary cause  of  the  disease.  But  in  certain  cases  there  was  a  constitutional 
condition  or  diathesis  in  which  there  was  an  excess  of  phosphates  and 
carbonates  of  lime  in  the  circulation,  and  this  condition  exerted  an  in- 
fluence in  the  production  of  the  disease.  This  condition  or  diathesis  was 
probably  due  to  dyspepsia,  excessive  fatigue,  mental  or  physical  overwork, 
protracted  illness,  or  any  unusual  strain  on  the  system.  He  thought  it 
safe  to  say  that  ninety-five  per  cent,  of  the  cases  seen  in  private  practice 
are  ^^  due  to  the  deimsit  locally  of  lime-salts  ahout  rough  surfaces  on  the  teeth, 
the  nucleus  being  usually  at  the  point  where  the  enamel  joins  the 
cementum." 

Walker  (1881),  |  in  a  paper  upon  the  disorder,  expressed  the  opinion 
that  its  origin  was  local,  and  that  the  starting-point  of  the  disease  was  to 
be  found  in  a  subacute  inflammation  of  the  gum  which  passed  into  the 
depths  of  the  alveolar  process. 

Witzel  (1882)  §  regarded  the  disease  as  a  purely  local  affection,  having 
no  constitutional  relations  whatever.  He  asserted  that  the  primary  origin 
of  the  disease  was  an  inflammatory  condition  of  the  alveolus^  accompanied 
by  caries  of  the  border  and  followed  by  a  deposit  of  calcic  material  just 
beneath  the  free  margin  of  the  gum,  which  caused  the  gingivae  to  become 
retracted  and  reverted.  The  infection  of  the  carious  material  with  micro- 
organisms developed  pus,  which  became  infectious  to  a  greater  or  less 
extent-.  He  therefore  termed  the  disease  "infectious  alveolitis,"  and  de- 
scribed it  as  a  molecular  necrosis  of  the  alveoli,  or  caries  of  the  dental 
sockets,  produced  by  septic  irritation  of  the  medulla  of  the  bone. 

Black  (1886),  1 1  in  a  most  exhaustive  article,  gives  it  as  his  opinion  that 
pyorrhoea  alveolaris  is  a  local  disorder.  He,  however,  describes  two  forms 
of  the  disease  ;  one  he  terms  calcic  inflammation,  the  other  phagedenic  peri- 
cementitis. The  former  he  believed  to  be  due  to  calcic  material  dei30sited 
at  the  necks  of  the  teeth,  which  gradually  encroached  upon  the  peri- 
cementum, establishing  suppurative  inflammation,  while  the  latter  form 
was  characterized  by  a  phagedenic  state, — or  destructive  ulceration  of  the 
gingivae, — and  destruction  of  the  peridental  membrane  and  alveolar  walls. 
He  thinks  this  destructive  inflammation  of  the  peridental  membrane  is 
distinctive  from  other  inflammations  of  this  tissue,  and  that  a  serumal  cal- 
culus may  be  associated  with  its  origin.  He  looks  upon  the  disease  as 
having  its  primary  origin  in  the  peridental  membrane  rather  than  in  the 
alveolus,  although  the  destruction  of  these  tissues  apparently  goes  on 
together. 

*  Wiener  med.  Presse,  vol.  xvi. 

t  Dental  Cosmos,  vol.  xxiii. 

X  Transactions  of  the  International  Medical  Congress,  1881. 

§  British  Journal  of  Dental  Science,  vol.  xxv. 

II  American  System  of  Dentistry,  vol.  i. 


PYOERHOEA   ALVEOLA  RIS.  539 

Talbot  (1886)  *  stated  that  it  was  his  opinion  that  the  disease  was  a 
local  one,  witli  both  local  and  constitutional  causes.  He  believed  the  dis- 
ease began  as  a  simple  inflammation  of  the  gums  which  later  became 
chronic. 

Sudduth  (1894)  f  offered  the  suggestion  that  the  principal  exciting  cause 
of  pyorrhoea  alveolaris  was  the  lactic  acid  formed  in  the  mouth  by  fermen- 
tation. 

Arrington  (1900)  J  takes  an  extreme  view  of  the  origin  of  the  disease, 
and  maintains  that  there  is  but  one  form^  although  there  are  sundry  feat- 
ures that  present  as  the  disease  progresses.  He  believes  that  it  is  not 
dependent  upon  any  particular  state  of  the  system  for  its  origin,  for  all 
individuals  alike,  the  robust  and  the  feeble,  seem  to  be  equally  subject  to 
it ;  nor  is  it  a  consequence  of,  or  in  any  way  complicated  with,  any  other 
disease. 

Bacterial  Origin  of  the  Disease. — Archovy  and  Izklai  (1881), §  in 
discussing  Dr.  Walker's  paper,  read  at  the  International  Medical  Congress, 
London,  both  ascribed  the  disorder  to  parasites  or  minute  organisms. 

Archovy  (1884)  ||  shared  the  opinion  of  Witzel,  that  the  disease  was  a 
marginal  necrosis  of  the  alveolus,  caused  by  a  septic  irritation,  probably 
the  result  of  minute  organisms.  He  termed  the  disease  caries  alveolaris 
specijica.  '^The  nature  of  the  affection  is  that  of  a  suppurative  inflam- 
mation which  spreads  to  all  parts  lying  between  the  gum  and  the  dentin 
of  the  root." 

Malassez  and  Galippe  (1884)  considered  the  disease  as  undoubtedly  of 
parasitic  origin,  ''which  may  be  proved  by  an  examination  of  stained 
sections  ;  by  cultivation  and  isolation  of  the  parasites  contained  in  the 
dental  tubules ;  by  the  contagion  spreading  from  tooth  to  tooth,  as  well  as 
from  individual  to  individual,  as  we  observed  more  than  once  in  persons 
of  different  sex  who  stand  in  intimate  relations  to  each  other." 

Galippe  (1888)  ^  thought  he  had  found  the  specific  organism  of  the  dis- 
ease, which  was  designated  by  the  Greek  letters  rj  and  /?.  Galippe' s  claims 
have  not  been  substantiated  by  later  observation  and  research. 

Magitot,**  in  reviewing  the  labors  of  Malassez  and  Galippe,  does  not 
combat  the  theory  of  the  parasitic  nature  of  the  disease,  and  concludes 
his  remarks  with  three  propositions  : 

1.  The  affection  characterized  by  alveolar  suppuration  and  by  loosen- 
ing and  falling  out  of  the  teeth  should  be  designated  as  a  true  sympto- 
matic alveolar  arthritis,  septic  and  contagious. 

2.  It  generally  arises  under  the  influence  of  certain  unfavorable  con- 
ditions of  health  and  diathesis,  also  in  exanthematic  fevers,  etc.,  where  it 
manifests  itself  either  as  a  complication  or  as  a  consequence. 

*  Dental  Cosmos,  vol.  xxviii. 
t  Ibid.,  vol.  xxxvi. 

%  International  Dental  Journal,  July,  1900. 
§  Transactions  of  the  International  Dental  Congress,  1881. 
II  Diagnostik  der  Zahnkrankheiten,  1885,  S.  232. 
\  Die  infectiose  arthro-dentare  Gingivitis,  1888. 
*^  Miller's  Micro-Organisms  of  the  Human  Mouth,  p.  324. 


540  OPERATIVE   DENTISTRY. 

3.  The  therapeutics  should  consist  chiei3y  in  the  application  of  anti- 
septics, local  alteratives,  astringents,  or  caustics. 

Miller  (1890)  *  was  unable  to  discover  any  specific  micro-organism  in 
the  pus  discharged  from  cases  of  pyorrhoea  alveolaris.  Out  of  twenty- 
six  different  cases  examined,  twenty-two  different  kinds  of  bacteria  were 
found.  In  cases  8  and  13,  and  in  16  and  17,  the  bacteria  were  found  to  be 
identical.  He  therefore  concludes  that  there  is  no  specific  bacterium  yet 
found  for  this  disease,  as  the  four  cases  in  which  the  bacteria  were  iden- 
tical proved  nothing.  But  if  there  is  such  an  organism,  it  will  not  grow 
on  gelatin,  and  he  suggests  that  in  further  experiments  media  should  be 
selected  which  can  be  kept  at  the  temperature  of  the  mouth.  It  may  be 
possible,  however,  if  such  a  bacterium  exists,  that,  like  many  other  mouth 
bacteria,  it  is  not  cultivable  on  any  of  the  artificial  nutrient  media. 

Whittles  (1898)  f  says  that  in  all  genuine  cases  of  pyorrhoea  alveolaris 
which  he  has  examined  he  has  found  in  the  pus  a  ' '  particular  bacterium 
which  is  probably  of  the  anaerobic  variety."  The  discovery  of  this 
organism,  which,  by  the  way,  is  not  described,  led  him  to  search  for  an 
efiicient  antidote,  which  he  found  in  the  "green  iodide  of  mercury," 
triturated  in  a  mortar  with  a  little  glycerol  to  allow  of  greater  readiness 
of  application  to  the  sulci  or  pus  pockets  of  the  affected  teeth. 

He  looks  upon  the  disease  as  another  example  of  those  affections  which 
accompany  a  general  lowered  condition  of  the  mesoblastic  element  as  a 
predisposing  cause,  the  real  excitant  being  a  bacterium. 

Younger  (1900)  J  thinks  that  Cook  has  discovered  a  specific  organism 
for  the  disease,  as  a  certain  form  was  constant  in  his  cultivations.  No 
definite  description  is  given  of  the  organism,  as  it  was  still  under  culti- 
vation and  observation. 

From  the  foregoing  resumS  of  the  theories  which  have  been  advanced 
to  account  for  the  origin  of  pyorrhoea  alveolaris,  and  the  facts  which  have 
been  deduced  by  observation  and  experiment,  it  is  evident,  that  such 
diverse  etiologic  factors  cannot  all  of  them  be  the  real  cause  of  a  single 
form  of  the  disease. 

There  is  no  doubt  that  a  considerable  number  of  cases  of  the  affection 
are  due  primarily  to  certain  acquired  systemic  conditions,  like  syphilis, 
mercurialism,  iodism,  anaemia,  dyspepsia,  scurvy,  malaria,  typhoid  fever, 
diabetes  mellitus,  albuminuria,  etc.,  or  to  inherited  disease,  like  congenital 
syphilis,  or  to  inherited  tendencies  to  diseases  like  tuberculosis,  gout,  and 
rheumatism,  which  induce  trophic  changes  in  the  tissues  and  establish  a 
predisposition  to  early  senile  degenerations  ;  while,  upon  the  other  hand, 
a  considerable  number  of  cases  are  due  entirely  to  certain  local  irritative 
conditions  induced  hy  the  formation  of  salivary  concretions  deposited  at  the 
cervices  of  the  teeth  and  upon  the  sides  of  the  roots,  which  by  their  en- 
croachment upon  the  pericementum  induce  inflammation  of  a  suppurative 
character,  accompanied  in  its  later  stages  by  ulceration  of  this  membrane, 
disintegration  of  the  alveolar  border,  and  recession  of  the  gum. 

*  Micro-Organisms  of  the  Human  Mouth. 

t  Dental  Cosmos,  vol.  xl.  %  Ibid.,  1900. 


PYOREHCEA    ALVEOLARIS.  541 

It  is  a  very  doubtful  supposition,  however,  tliat  the  disease  is  ever 
caused  primarily  by  infection  of  the  tissues  with  the  pyogenic  cocci,  or  by 
any  specific  bacterium.  It  would  seem  more  probable  that  the  infection 
was  a  secondary  factor  or  exciting  cause,  while  the  primary  cause  was 
a  lowered  vitality  of  the  tissues,  due  to  some  previous  or  exciting  systemic 
condition,  or  to  injury  by  local  irritants,  which  had  placed  the  parts  in 
such  a  condition  that  they  were  unable  to  resist  the  action  of  the  pyogenic 
micro-organisms  which  are  always  present  in  the  mouth. 

The  disease  may  therefore  be  divided  into  three  general  forms, — one 
arising  from  purely  local  causes,  the  others  from  constitutional  or  systemic 
conditions,  the  first  of  which  may  be  termed,  as  suggested  by  Peirce,  ^^ptya- 
logenic  calcic  pericementitis  ;"  the  second,  ^ '  hcematogenic  calcic  per  Icementitis  f^ 
and  the  third,  '■^ phagedenic  pericementitis,^^  as  suggested  by  Black. 

PTYALOGENIC   CALCIC   PERICEMENTITIS. 

Causes. — This  form  of  the  disease  has  its  origin  in  those  systemic  and 
local  conditions  which  are  thought  to  produce  inflammation  of  the  gums. 
These  causes  are  predisposing  and  exciting,  general  and  local.  Dental 
pathologists  are  inclined  to  divide  inflammation  of  the  gums  into  two  dis- 
tinct forms,  one  which  is  general  in  its  character  and  termed  gingivitis  or 
ulitis,  and  another  which  is  confined  to  the  borders  or  margins  of  the  gums 
and  termed  marginal  gingivitis. 

Marginal  gingivitis  is  often  catarrhal  in  character,  and  may  be  asso- 
ciated with  catarrhal  stomatitis,  and  not  infrequently  precedes  ulcerative 
stomatitis. 

In  this  form  of  gingivitis  ptyalogenic  calcic  pericementitis  is  thought 
to  have  its  origin. 

The  predisposing  causes  of  marginal  gingivitis  are  general  and  local. 
The  general  predisposing  causes  are  those  conditions  which  are  associated 
with  a  faulty  metabolism, — conditions  which  lower  the  vital  resistance  of 
the  tissues  and  predispose  them  to  inflammation,  suppuration,  and  various 
degenerative  changes.  The  local  predisposing  causes  are  lack  of  exercise 
and  the  impaction  and  decomposition  of  food  debris.  The  local  exciting 
causes  are  various  irritants  of  a  mechanic,  chemic,  and  septic  nature,  like 
harsh  brushing,  salivary  calculus,  irritating  drugs,  and  micro-organisms. 

The  presence  of  a  marginal  gingivitis,  either  local  or  general  in  char- 
acter, presents  the  most  favorable  conditions  for  the  establishment  of 
ptyalogenic  calcic  j)ericementitis  that  could  possibly  be  arranged,  for  by 
the  swelling  and  loosening  of  the  gums  at  the  cervices  of  the  teeth  pockets 
or  sulci  are  formed  for  the  lodgement  of  debris,  while  the  tenacious  pro- 
duct of  the  mucous  glands— mucin — acts  as  a  nidus  for  the  formation  of 
subgingival  deposits,  which  "are  produced  by  precipitation  of  the  calcic 
material  held  in  solution  in  the  secretions  through  the  action  of  the 
products  of  fermentation  upon  these  fluids ;"  *  and  thus  the  calcic  mate- 
rial is  deposited  in  the  pockets,  and  by  reason  of  the  fact  that  it  remains 
undisturbed  in  these  locations  it  accumulates  more  or  less  rapidly  and 

*  Dental  Cosmos,  vol.  xxxvi. 


642  OPERATIVE    DENTISTRY. 

becomes  very  dense.  Its  peculiar  density  is  due  to  the  fact  tliat  it  con- 
tains less  food  debris  and  leptothrix  than  the  common  form  of  salivary 
calculus. 

Pathology  and  Morbid  Anatomy. — Ptyalogenic  calcic  pericementitis 
is  characterized  by  the  presence  of  subgingival  calcic  concretions,  dark 
green  in  color,  very  hard,  and  deposited  in  the  form  of  thin  scales  u^Don 
the  sides  of  the  roots  in  open  pockets,  beginning  at  the  cervix  and  extend- 
ing in  a  direction  towards  the  apex. 

The  formation  of  this  deposit  is  doubtless  due  to  a  catarrhal  condition 
of  the  mucous  membrane  of  the  mouth,  resulting  in  a  marginal  gingivitis. 
The  calcic  material  is  derived  partly  from  the  salivary  secretions  and  partly 
from  the  exudations  and  abnormal  secretions  of  the  mucous  membrane  and 
the  gums. 

The  effect  of  this  deposit  when  once  formed  is  to  establish  a  continuous 
irritation  of  the  margins  of  the  gums,  thus  keeping  up  the  inflammation 
and  exciting  degenerative  changes  not  only  in  this  tissue  but  also  in  the 
pericementum  and  alveolar  border. 

The  existence  of  a  persistent  mechanic  irritation  causes  in  this  case  a 
chronic  hypersemia  of  the  gum  and  pericementum,  which  lowers  the  vital 
resistance  of  these  tissues  and  places  them  in  a  condition  to  be  readily 
acted  upon  by  the  pyogenic  micro-organisms  which  are  always  present  in 
the  food  debris  and  mixed  secretions  of  the  mouth. 

As  a  result  of  the  inflamed  condition  of  the  margins  of  the  gums  they 
become  swollen  and  everted,  forming  a  space,  sulcus,  or  pocket  between 
the  tooth  and  the  gum,  to  which  the  altered  secretions,  food  debris,  and 
the  saliva  have  free  access.  Precipitation  of  calcic  material  takes  place, 
probably  as  a  result  of  the  products  of  fermentation  coming  in  contact 
with  the  fluids  of  the  mouth  which  hold  the  calcium  salts  in  solution,  and 
thus  little  by  little  the  concretions  are  built  up.  " 

Burchard*  says,  ''It  is  probable  that  these  deposits  have  their  origin 
in  a  reaction  between  the  altered  mucous  secretion  of  the  gingival  glands 
and  the  products  of  lactic  fermentation,  their  calcic  salts  being  derived 
from  the  saliva." 

The  calcic  deposits  which  are  found  upon  the  sides  of  the  roots  of  the 
teeth  at  remote  points  from  the  margin  of  the  gums,  but  which  are  in 
communication  with  the  secretions  of  the  mouth  through  open  pockets, 
are  productive  of  great  damage  to  the  integrity  of  the  peridental  tissues, 
sometimes  causing  acute  diffuse  suppurative  inflammation  and  destruc- 
tion of  the  pericementum,  or  of  chronic  inflammation  and  ulceration  of  the 
gum  and  pericementum,  with  a  discharge  of  fetid  pus,  necrosis  of  the 
alveolar  border  (caries),  and  resorption  of  the  gum. 

In  the  first  or  acute  form  of  this  inflammation  the  process  of  destruc- 
tion in  the  tissues  is  often  very  rapid,  a  few  weeks  or  months  only  being 
required  to  cause  complete  exfoliation  of  the  tooth,  unless  the  concretions 
are  removed  ;  and  even  then  the  inflammatory  symptoms  do  not  always 
subside  nor  the  pockets  close,  but  resist  all  treatment  and  remain  in  a 

*  Pathology,  Therapeutics,  and  Pharmacology. 


PYOERHCEA    ALVEOLARIS.  543 

state  of  subacute  inflammation,  tlie  pericementum  thickened,  tlie  tooth 
loosened  in  its  alveolus,  and  gradually  extruding  or  turning  upon  its  axis, 
while  it  becomes  more  and  more  a  source  of  irritation  and  annoyance  to  the 
patient  until  it  is  extracted  or  exfoliated. 

In  such  cases,  however,  there  is  always  associated  with  it  some  peculiar 
systemic  condition  or  dyscrasia,  like  tuberculosis,  syphilis,  diabetes,  albu- 
minuria, or  anaemia,  which  aggravates  the  local  conditions  and  retards  or 
prevents  the  healing  process. 

In  the  second  or  chronic  form  of  the  inflammation  the  process  of  de- 
struction in  the  pericementum  and  the  surrounding  structures  is  much  less 
rai^id  and  the  symptoms  are  all  less  aggravated,  and  whereas  in  the  acute 
form  of  the  inflammatory  process  the  tooth  may  be  exfoliated  in  a  few 
weeks  or  months,  in  the  chronic  form  of  the  disease  this  process  may  be 
extended  over  as  many  years.  A  large  per  cent,  of  the  latter  cases  are 
amenable  to  surgical  treatment,  and  these  are  the  cases  of  pyorrhoea  alveo- 
laris  which  are  so  often  advertised  as  cured.  The  cause  of  irritation  is  a 
purely  local  one, — a  mechanic  irritant ;  therefore  when  the  cause  is  removed 
and  the  parts  are  assisted  in  the  healing  process  a  cure  takes  i^lace. 

In  many  of  the  remaining  smaller  per  cent,  of  cases,  which  do  not 
readily  respond  to  treatment,  there  is  often  a  history  either  of  gout,  rheu- 
matism, malaria,  anaemia,  leukaemia,  nephritic  diseases,  physical,  nervous, 
or  mental  debility,  reflex  neurosis,  or  in  married  females  of  frequent  preg- 
nancies or  prolonged  lactations.  Sometimes  local  conditions  are  present 
which  produce  over-stimulation  or  under-stimulation  of  the  circulation 
of  the  pericementum,  like  malocclusions  of  the  teeth,  or  loss  of  occlusion, 
which  would  in  the  one  case  predispose  them  to  hypersemia  and  inflamma- 
tion of  the  pericementum,  and  in  the  other  to  atroi^hy,  thus  lowering  the 
vital  resistance  of  the  tissues  and  preparing  the  way  for  the  destructive 
action  of  the  pyogenic  micro-organisms. 

The  individuals  who  are  the  most  liable  to  suffer  from  this  form  of 
pyorrhoea  alveolaris  usually  possess  teeth  of  finely  organized  structure, 
which  are  very  resistant  to  cutting  instruments  and  singularly  free  from 
dental  caries.  These  facts  were  noticed  by  the  earliest  writers  upon  the 
disease,  and  were  classed  by  them  as  predisposing  etiologic  factors,  as  it  was 
thought  that  their  density  and  consequent  low  vitality  predisposed  them  to 
exfoliation  when  attacked  by  inflammatory  disease  of  the  root. 

Harris*  says,  "It  may  also  be  produced  by  very  hard  teeth  which,  in 
consequence  of  their  density,  possess  only  a  very  low  degree  of  vitality ; 
for  cases  of  recession  of  the  gums,  in  which  a  very  slight  inflammatory 
action  exists,  are  frequently  met  with  in  individuals  having  teeth  of  this 
description.  This  can  only  be  explained  by  supposing  a  want  of  congeni- 
ality between  these  organs  and  the  more  sensitive  and  highly  vitalized 
parts  with  which  they  are  in  immediate  contact." 

On  making  sections  of  these  teeth,  the  enamel  and  dentin  are  found  to 
be  exceedingly  hard  and  much  more  translucent  than  the  average  tooth. 
The  pulp-chamber  is  usually  considerably  contracted,  the  pulp  often  show- 

*  Harris's  Dental  Surgery. 


544  OPERATIVE    DENTISTEY. 

ing  evidences  of  calcification,  atrophy,  and  other  senile  changes.  In  the 
later  stages  of  the  disease  the  vitality  of  the  pulp  is  often  destroyed  by  the 
intense  inflammation  of  the  tissues  of  the  apical  space,  the  swelling  pro- 
ducing pressure  ujjon  the  pulp-vessels. 

An  examination  of  the  root  reveals  the  fact  that  the  pericementum  is 
greatly  inflamed  or  undergoing  degenerative  changes  (Fig,  624),  or  has 
been  destroyed  to  a  greater  or  less  extent  according  to  the  character  and 
stage  of  the  disease  when  the  tooth  was  removed.  Wherever  tophi  (con- 
cretions) have  formed  upon  the  root  the  j)ericementum  will  be  missing, 
not  only  upon  that  portion  of  the  root  covered  by  the  deposit  but  for 
a  considerable  area  beyond ;  this  is  a  constant  condition.  It  not  infre- 
quently happens  that  the  pericementum  will  be  destroyed  upon  one  side 
of  the  root  from  the  cervix  to  the  ajDex  while  it  will  be  intact  over  the 
remaining  surfaces ;  or  it  may  be  destroyed  upon  all  sides  but  one  ; 
and,  again,  the  process  of  destruction  may  encircle  the  tooth  for  an  equal 
distance  upon  all  sides.  The  latter  condition  is  most  often  associated 
with  the  anterior  teeth,  and  especially  when  the  tooth  has  no  immediate 
neighbors. 

As  the  disease  progresses  the  teeth  become  more  and  more  loosened  in 
their  alveoli,  until  finally  they  drop  out  or  have  to  be  extracted  to  relieve 
the  intense  soreness  which  is  developed  as  a  result  of  their  mobility  and 
frequent  injuries  due  to  their  elongation  and  malocclusion. 

In  cases  of  long  standing  a  secondary  form  of  deposit  is  often  observed 
upon  the  roots  of  these  teeth.  The  primary  deposit  is  formed  in  thin 
scales  just  beneath  the  gum  margin  ;  the  secondary  is  formed  beyond  the 
primary  deposit,  upon  the  denuded  cementum,  in  those  locations  which 
are  constantly  bathed  in  pus.  The  secondary  deposits  are  so  different  in 
appearance  that  they  cannot  be  mistaken  for  the  primary  deposit ;  for,  in- 
stead of  being  formed  in  thin  scales  with  an  even  surface,  they  are  formed 
either  in  tiny  bead-like  islands  or  in  larger  masses  with  bead-like  projec- 
tions upon  the  surface,  and  very  similar  in  appearance  to  the  concretions 
formed  upon  bodies,  either  animal  or  mineral,  that  have  been  lodged  in 
the  tissues  and  bathed  in  pus  for  a  considerable  period  of  time.  Such 
deposits  are  frequently  seen  upon  the  ajpical  portion  of  the  roots  of  teeth 
which  have  been  the  subject  of  long- continued  chronic  alveolar  abscess. 
They  are,  therefore,  not  the  primary  cause  of  the  disease,  but  the  result 
of  chronic  inflammation  and  deposition  of  calcareous  material  from  the 
inflammatory  products. 

Symptoms  and  Diagnosis. — The  first  symptom  of  the  disease  in  its 
early  stages  is  usually  inflammation  of  the  margins  of  the  gum, — marginal 
gingivitis,— which  are  turgid  and  reddened,  the  tips  of  the  festoons  often 
being  of  a  purplish  color. 

The  extent  of  the  swelling  and  discoloration  will  depend  upon  the 
severity  of  the  inflammation  and  the  diathesis  of  the  individual.  The 
gums  bleed  readily  upon  the  least  friction  or  rough  usage.  The  margins 
of  the  gums  are  slightly  everted,  and  the  sulci  or  pockets  formed  between 
the  margins  of  the  gums  and  the  cervices  of  the  teeth  are  filled  with  food 
debris  and  thickened  mucous  secretions,  or  a  thick,  cheesy  mass  of  material 


Fig.  624. — Inflamed  peridental  membrane  from  a  case  of  pyorrhcea  alveolaris.     >'  50. 


PYOERHCEA    ALVEOLARIS.  545 

made  up  of  these  substances  and  epithelial  scales,  numerous  forms  of  bac- 
teria, and  calcic  material. 

Later  in  the  history  of  the  case,  if  an  instrument  is  passed  beneath  the 
margins  of  the  gum,  a  scaly  deposit  of  dark-green  calculus  will  be  found 
adherent  to  the  cervix  of  the  tooth.  This  may  be  upon  one  surface  only, 
or  it  may  encircle  a  larger  portion  or  the  whole  of  the  cervix. 

Occasionally,  however,  cases  will  present  in  which  the  deposit  seems 
to  have  occurred  before  the  marginal  gingivitis  was  developed,  and  that 
the  deposit  was  the  cause  of  the  gingivitis.  These  cases  may  have  their 
origin  in  cervical  dejiosits,  which  later  develop  a  chronic  marginal  gingivitis, 
as  already  described  in  the  i^receding  chapter,  or  it  may  be  that  the  inflam- 
matory condition  of  the  gum  has  subsided  after  the  formation  of  a  com- 
paratively smooth  calculus. 

As  the  formation  of  the  calculus  progresses  it  encroaches  upon  the 
periosteum,  causing  inflammation  and  ulceration  of  this  membrane.  The 
constant  presence  of  the  i3yogenic  bacteria  in  the  mouth  affords  the  means 
of  septic  infection,  which  attacks  the  tissues  as  soon  as  they  can  gain  an 
entrance  to  them  through  an  abraded  surface  or  other  break  in  their  con- 
tinuity. As  a  result  pus  is  formed,  which  may  be  pressed  from  beneath 
the  margins  of  the  gums.  An  examination  of  the  margins  of  the  alveolus 
with  a  fine  probe  will  sometimes  discover  these  edges  eroded  by  caries,  but 
more  often  they  will  not  be  found  uncovered,  the  process  of  destruction 
seeming  to  be  one  of  resorption  rather  than  molecular  disintegration  by 
caries.  In  the  former  cases  the  odor  of  the  pus  is  very  ofl'ensive  and  dis- 
agreeably taints  the  breath. 

As  the  disease  advances  the  pericementum  and  the  alveolar  process  are 
progressively  destroyed,  and  the  gum  gradually  recedes  as  this  process 
continues,  until  the  tooth  becomes  very  loose  in  its  alveolus.  The  increased 
mobility,  elongation,  and  the  malocclusion  incident  to  these  conditions 
excite  inflammatory  action  in  the  tissues  beyond  the  field  of  the  original 
disease,  thus  increasing  the  soreness  and  discomfort  of  the  tooth. 

In  some  cases,  at  this  stage  of  the  disease,  hy]3ersemia  of  the  pulp  may 
be  developed,  followed  by  embolism  and  death,  or  the  inflammation  and 
<]edema  of  the  apical  tissues  may  be  so  great  as  to  cause  strangulation  of 
the  vessels  of  the  pulji  at  the  apical  foramen.  As  a  result  of  the  devitali- 
zation of  the  pulp  and  septic  infection,  the  case  may  now  be  complicated 
with  a  septic  apical  pericementitis. 

The  termination  of  the  disease  is  in  the  exfoliation  of  the  tooth.  All 
inflammatory  symptoms  immediately  subside  upon  the  loss  of  the  tooth, 
and  the  gums  and  alveolar  border  assume  in  a  very  short  time  a  healthy 
appearance. 

Prognosis. — The  prognosis  is  favorable,  even  in  the  later  stage  of  the 
disease,  provided  the  exciting  causes  can  be  removed  and  the  constitutional 
predisposing  causes,  when  they  exist,  corrected. 

Treatment. — In  the  treatment  of  ptyalogenic  calcic  pericementitis 
there  are  two  main  objects  to  be  considered.  The  first  is  the  removal  of 
all  sources  of  irritation,  and  the  second  is  supporting  the  diseased  teeth  so 
as  to  secure  surgical  rest  during  the  healing  process. 

35 


546 


OPERATIVE    DENTISTRY. 


The  removal  of  the  sources  of  irritation  comprehends  all  forms  of  local 
and  constitutional  irritants.  The  principal  local  irritants  are  the  calcic 
deposits,  food  debris^  and  septic  bacteria.  The  removal  of  the  deposits  is 
a  surgical  procedure,  and  requires  special  instruments  for  its  success. 

Instruments  of  an  entirely  different  form  are  required  in  the  removal  of 
the  subgingival  salivary  deposits  from  those  employed  in  removing  the  ordi- 
nary forms  of  salivary  calculus. 

The  most  important  desiderata  in  the  instruments  used  for  the  purpose 
of  removing  the  deposits  from  the  sides  of  the  roots  beneath  the  gums  are, 
first,  that  they  shall  be  so  thin  that  they  will  pass  readily  into  the  pockets 
formed  in  the  alveolar  wall  between  the  root  of  the  tooth  and  the  gum  ; 

Fig.  625. 


After  Burchard. 


second,  so  flexible  or  springy  that  when  the  flat  side  of  the  instrument  is 
laid  against  the  side  of  the  root  a  lateral  and  downward  pressure  will  cause 
the  instrument  to  glide  over  its  surface,  removing  any  concretions  that 
may  be  thereon,  but  not  cutting  into  the  cementum. 

These  hard  salivary  concretions  are  most  readily  removed  or  scaled  from 
the  surface  of  the  root  by  driving  or  pushing  the  instrument  from  the 
margin  of  the  gum  towards  the  apex  of  the  tooth,  keeping  the  flat  side  of 
the  instrument  always  in  contact  with  its  surface.  For  this  purpose  chisel- 
shaped  instruments  only  should  be  used.     Fig.  625  shows  the  manner  of 


PYOREHCEA    ALVEOLARIS. 


547 


holding  tlie  iustrument,  and  Fig.  626  tlie  application  of  the  instrument  ta 
the  root  of  the  tooth. 

Some  operators,  however,  prefer  instruments  which  can  be  used  with  a 
drawing  motion,  the  cutting  end  of  which  is  made  like  the  hoe  excavator, 
but  with  the  blade  much  shorter.     This  of  course  makes 
the  instrument  bulky  at  its  cutting  end,  and   prevents  Fig.  626. 

it  from  being  carried  as  near  to  the  apex  of  the  root  as 
is  possible  with  the  thin  chisel-shaped  instrument ;  hence 
there  is  not  the  same  certainty  that  the  concretions  are 
all  removed  in  the  farthest  limits  of  the  pockets  as  would 
be  the  case  if  the  chisel-shaped  instruments  were  em- 
ployed. The  instruments  best  suited  to  this  purpose  are 
the  Allport  and  the  Gushing  scalers  (Figs.  627  and  628). 

The  importance  of  the  thorough  removal  of  every 
particle  of  the  deposit  from  beneath  the  gums  cannot  be 
over-estimated.  Many  failures  to  arrest  the  inflamma- 
tory symptoms  in  these  cases  can  be  traced  to  the  fact 
that  some  small  particle  of  adherent  deposit  has  not  been  After  Burchard. 
reached. 

The  operation  even  under  the  most  favorable  circumstances  presents 
many  obstacles  and  difficulties,  which  can  only  be  overcome  by  those  opera- 
tors whose  sense  of  touch  has  become  so  acute  as  to  be  almost  the  equal  of 
vision.  The  six  anterior  teeth  of  both  jaws  present  the  most  favorable 
conditions  for  the  successful  removal  of  such  concretions.  These  difficul- 
ties, however,  are  greatly  increased  in  the  bicuspids  and  the  molars  by  their 

Fig.  627. 


Allport's  pyorrliiX'a  alveolaris  instruments. 

more  inaccessible  location,  by  their  shape,  and  the  number  of  their  roots. 
The  most  difficult  problem  is  the  removal  of  the  deposits  fi'om  the  bifur- 
cations of  the  roots  and  from  the  surfaces  of  the  roots  which  look  towards 
each  other. 

After  the  concretions  have  all  been  dislodged  from  their  attachment  to 
the  root,  the  pockets  should  be  injected  with  a  drop  or  two  of  hydrogen 
dioxide  (H^OJ  by  the  use  of  the  Dunn  medicinal  drop  syringe  (Fig.  629),  in 


548 


OPERATIVE   DENTISTRY. 


order  to  free  the  pockets  from  all  calcareous  debris  ;  after  which  they  may- 
be treated  by  the  application  of  aromatic  sulphuric  acid,  lactic  acid, 
trichloracetic  acid,  or  a  saturated  solution  of  iodine  crystals  in  beech- 
wood  creosote.  Various  other  remedies  are  employed  for  the  treatment 
of  the  pockets,  but  the  mention  of  these  is  sufficient  to  indicate  their 
character. 

The  after-treatment  consists  in  the  free  use  of  antiseptic  mouth-washes 

Fig.  628. 


Cushing's  pyorrhoea  alveolaris  instruments. 

and  painting  the  gums  with  equal  parts  of  tincture  of  iodine  and  tincture 
of  aconite  every  other  day  for  a  week  or  ten  days. 

The  writer  has  for  many  years  been  in  the  habit  of  employing  an 
atomizer  for  applying  the  antiseptic  lotions  or  mouth-washes  in  the  treat- 
ment of  these  oral  conditions.  The  patient  is  instructed  to  thoroughly 
brush  the  teeth  after  each  meal,  then  to  i)ass  floss-silk  between  all  of  the 
teeth,  and  follow  this  cleansing  process  with  the  atomizer,  using  sufficient 
force  to  drive  the  antiseptic  fluid  through  the  interdental  spaces.  If  by 
the  end  of  a  week  the  gums  have  not  assumed  their  normal  color,  or  there 
is  still  a  discharge  of  pus  from  any  pocket,  the  chances  are  that  a  small 
adherent  scale  of  calculus  still  remains.  This  should  be  searched  for  and 
removed  and  the  case  treated  as  before.     In  all  of  those  cases  that  are 


Fig.  629. 


Dunn  medicinal  drop  syringe. 

complicated  with  systemic  disorders  which  predispose  to  pericemental 
degenerative  changes,  attemj)ts  should  be  made  through  the  family  medi- 
cal adviser  to  correct  these  conditions. 

Local  treatment  under  such  circumstances,  although  it  may  prove  help- 
ful in  relieving  immediate  suffering  and  placing  the  mouth  and  teeth  in 
a  more  hygienic  condition,  will  not  prove  curative  until  the  constitutional 
dyscrasia  is  improved. 


PYORRHCEA    ALVEOLA  RIS. 


549 


Surgical  Rest. — Teeth  which  have  become  much  loosened  by  reason 
of  the  resorption  of  the  alveoli  must  be  given  surgical  rest  if  the  healing 
process  is  to  be  successfully  completed.  This  rest  may  be  secured  by  sup- 
porting the  teeth,  either  by  ligatures  of  silk  or  linen  attached  to  contiguous 
teeth,  or  by  wire,  either  of  gold  or  silver,  or  by  splints  made  of  gold  or 
platinum  and  cemented  to  the  teeth. 

These  splints  (Fig.  630)  are  most  readily  made  by  fitting  thirty-four 
to  thirty-six  gauge  bands  to  the  individual  teeth,  taking  an  impression  of 
them  in  situ,  investing,  and  soldering  the  whole  together. 


Fig.  631. 


Fig.  630. 


Splint  prepared.    (After 
Burchard.) 


Labial  view  of  splint  in  po- 
sition.   (After  Burchard.) 


Fig.  632. 


Lingual  view  of  swaged 
splint  in  position.  (After 
Burchard. ) 


Fig.  631  shows  this  splint  after  it  has  been  cemented  in  position.  Or  an 
impression  may  be  taken  of  the  teeth  after  they  are  supported  with  silk 
ligatures,  and  a  splint  swaged  from  gold  or  platinum  and  cemented  in 
place,  as  shown  in  Fig.  632. 


OHAPTEE    XXXIX. 

HiEMATOGENIC   CALCIC   PERICEMENTITIS. 

This  form  of  pyorrhoea  alveolaris  is  found  most  frequently  in  persons 
suffering  from  certain  peculiar  inherited  or  acquired  constitutional  condi- 
tions,— viz.,  rheumatic  and  gouty  affections,  or,  in  other  words,  the  ar- 
thritic diathesis,  and  for  this  reason  it  has  been  termed  by  some  writers 
gouty  pericementitis. 

Magitot  (1867),  as  stated  in  the  preceding  chapter,  called  attention  to 
the  fact  that  in  his  opinion  persons  of  the  gouty  and  rheumatic  diathesis 
furnished  the  greatest  number  of  cases  of  pyorrhoea  alveolaris.  Eeese 
(1886)  i)ointed  out  most  clearly  the  association  of  this  disease  with  the 
gouty  diathesis.  The  writer  (1891)  demonstrated  the  analogy  between  the 
gouty  deposits  and  the  degenerations  of  the  fibrous  tissues  of  the  joints 
and  certain  pericemental  degenerations,  and  suggested  that  certain  deposits 
were  found  upon  the  roots  of  the  teeth  in  locations  which  had  no  com- 
munication with  the  salivary  secretions,  and  that  these  concretions  were 
deposited  from  the  elements  of  the  blood,  and  were  composed  of  the  urates 
of  lime  and  soda.  Peirce  (1892-94-95)  has  proved  by  careful  experiments 
the  truth  of  the  above  suggestions  of  the  writer  in  relation  to  the  location 
of  these  deposits  and  their  composition. 

The  demonstration  of  the  fact  by  Dr.  Peirce  that  the  deposits  found 
upon  the  roots  of  the  teeth  in  these  locations  gave  the  murexid  reaction 
proved  conclusively  that  they  contained  biurates,  the  same  as  found  in 
the  gouty  concretions  in  other  j)ortions  of  the  body.  The  establishment 
of  this  fact  gave  a  great  impetus  to  the  study  of  the  association  of  this 
disease  with  the  gouty  diathesis.  The  result  of  this  study,  however,  in 
certain  directions,  through  a  misunderstanding  of  the  premises  laid  down 
by  the  advocates  of  the  theory,  has  been  to  throw  doubt  upon  the  correct- 
ness of  their  conclusions.  The  teeth  that  have  been  used  in  these  studies 
by  the  opponents  of  this  theory  have  admittedly  been  taken  in  great 
quantity,  hap-hazard,  from  the  scrap-box  of  the  professional  extractors, 
which  made  it  impossible  to  obtain  the  history  of  a  single  case ;  neither 
could  there  be  any  means  of  knowing  whether  the  concretions  used  for  the 
chemical  analyses  were  deposited  from  the  saliva  in  open  pockets  or  from 
the  elements  of  the  blood  in  locations  where  the  secretions  of  the  mouth 
could  not  have  come  in  contact  with  them. 

These  are  important  distinctions,  and  if  they  are  observed  in  future 
researches  upon  this  subject  they  will  give  the  same  results  as  those 
obtained  by  Peirce  and  the  other  advocates  of  this  theory. 

Predisposing   Causes.— The  predisposing  causes  of  this   form  of 
pyorrhoea  alveolaris  (gouty  pericementitis)  are  those  conditions  of  the  sys- 
tem which  are  designated  as  the  gouty  and  rheumatic  affections.     Gouty 
pericementitis,  however,  is  only  a  local  manifestation  of  this  general  mor- 
550 


HEMATOGENIC    CALCIC    PEEICEMENTITIS.  551 

bid  state  of  the  system,  wliich  is  due  either  to  imperfect  metabolism  (sub- 
oxidation  and  faulty  elimination)  or  to  an  excessive  formation  of  uric  acid, 
resulting  in  the  accumulation  within  the  system  of  an  abnormal  amount  of 
certain  waste  products  termed  the  urates.  Individuals  who  are  thus  affected 
are  said  to  jDOSsess  the  uric  acid  or  gouty  diathesis.  It  must  be  remembered, 
however,  that  lead-poisoning  resembles  gout  in  giving  rise  to  an  excess  of 
uric  acid  in  the  blood. 

Urates  are  always  found  in  excess  in  the  serum  in  instances  of  deficient 
oxidation,  arthritis,  and  valvular  diseases  of  the  heart.  They  are  also 
found  in  the  urine,  as,  for  instance,  in  a  case  of  phthisis  where  an  insuffi- 
cient amount  of  oxygen  is  absorbed,  oxyhsemoglobin  is  deficient,  and  conse- 
quently many  of  the  normal  transformations  of  the  body  are  completely  or 
partially  arrested.  In  such  oases  quantities  of  oxalate  of  lime  will  be 
found  in  the  urine,  the  carbon  of  the  food  and  of  the  waste  material  from 
the  tissues  is  only  j^artially  oxidized,  and  that  which  should  have  been 
exhaled  from  the  lungs  as  carbonic  acid  is  excreted  by  the  kidneys  as 
oxalic  acid.  Again,  in  the  condition  of  venous  stasis  arising  from  feeble 
action  of  the  heart  the  blood  stagnates  in  the  veins,  becomes  loaded  with 
poisons,  is  not  carried  to  the  lungs  with  due  rapidity,  and  those  nitrogenous 
parts  of  food  and  tissue  which  normally  are  converted  into,  and  excreted 
as,  urea  appear  in  the  urine  as  uric  acid,  free  or  combined.     (Vaughn.) 

A  persistent  excess  of  uric  acid  in  the  urine  is,  therefore,  always  con- 
sidered as  a  significant  symptom  of  an  important  systemic  condition,  due 
to  an  increase  in  tissue  metabolism  in  some  particular  organ  or  group  of 
organs. 

Heredity. — The  gouty  diathesis  is  usually  inherited,  and  the  active 
manifestations  may  be  induced  in  such  individuals  by  high  living  or  by  the 
deprivations  of  extreme  poverty. 

Gairdner  and  Garrod  state  that  in  about  ninety  per  cent,  of  all  persons 
suffering  from  gout,  the  disease  also  existed  in  their  forefathers.  Peirce  is 
of  the  opinion  that  in  gouty  pericementitis  fully  ninety  per  cent,  manifest 
an  hereditary  tendency  to  the  disorder. 

Gout  diminishes  the  powers  of  resistance  against  disease  and  injuries, 
especially  when  the  kidneys  and  the  liver  are  affected.  Many  gouty  indi- 
viduals, however,  live  to  an  advanced  age. 

Diet. — The  excessive  use  of  foods  containing  large  quantities  of  nuclein 
or  saccharine  substances,  and  the  use  of  alcoholic  beverages,  particularly 
fermented  liquors,  are  predisposing  causes  of  gout,  and  also  of  this  form 
of  pyorrhoea  alveolaris. 

Sex. — Sex  does  not  seem  to  play  a  very  im]3ortant  part  in  the  predis- 
position to  pyorrhoea  alveolaris  in  general.  Men,  however,  are  much  more 
subject  to  gout  than  women,  and  as  a  natural  consequence  to  gouty  perice- 
mentitis. 

Age. — Gouty  manifestations  may  appear  at  any  period  of  life  from 
infancy  to  old  age.  It  is  most  common,  however,  after  middle  life.  This 
is  true  also  of  gouty  pericementitis,  although  cases  have  been  recorded  as 
occurring  before  the  age  of  puberty, 

Magitot  and  Peirce  both  agree  that  this  form  of   pyorrhoea  is  most 


552  OPERATIVE    DENTISTRY. 

frequent  between  the  ages  of  thirty  and  fifty  years,   and  that  it  rarely 
appears  after  the  age  of  sixty. 

Occupation . — Sedentary  occupations  are  important  predisposing  causes 
of  gouty  pericementitis,  as  they  favor  imperfect  oxidation  of  the  food, 
faulty  metabolism,  and  retard  the  elimination  of  the  waste  products.  Sys- 
tematic exercise  in  the  open  air  tends  largely  to  counteract  these  faults  in 
the  functions  of  the  body. 

This  morbid  state  of  the  system,  known  also  as  uricacidcemia  or  uricsemia, 
finds  expression  in  a  multitude  of  ailments  and  abnormal  conditions  of 
various  tissues  and  organs,  some  of  which  are  acute,  others  chronic,  in 
their  manifestations. 

Blood-Vessels. — Yarious  functional  and  organic  changes  are  found  in 
the  blood-vessels  of  gouty  subjects,  such  as  dilatation  of  the  aorta,  thick- 
ening of  the  walls  of  the  arteries,  loss  of  elasticity,  atheroma,  and  even 
calcification.  Phlebitis  is  a  well-recognized  gouty  ailment,  which  may 
produce  thrombosis,  and  by  dislodgement  of  the  clot  cause  sudden  death 
by  impaction  in  the  heart,  pulmonary  artery,  or  lungs. 

Circulation. — The  efi'ects  of  uricacidsemia  upon  the  circulation,  as 
pointed  out  by  Haig,  are  to  produce  "contraction  of  the  arterioles,  and  thus 
increase  arterial  tension."  When  these  conditions  affect  the  cerebral 
circulation  they  result  in  headaches,  mental  depression,  fatigue,  irrita- 
bility of  temper,  hysteria,  vertigo,  epilepsy,  and  convulsions. 

Asthma  and  chronic  bronchitis  are  often  the  result  of  the  effect  of  uric 
acid  upon  the  pulmonary  and  bronchial  circulation,  and  seem  to  explain 
the  association  so  often  noticed  between  these  affections  on  the  one  hand, 
and  gout  and  chronic  Bright' s  disease  upon  the  other. 

Dyspepsia  may  undoubtedly  be  produced  by  the  contraction  of  the 
arterioles  of  the  stomach  and  intestines,  thus  inhibiting  gastro-intestinal 
digestion  and  permitting  putrefactive  processes  to  take  their  jDlace,  which 
would  explain  the  association  between  dyspepsia  and  such  affections  as 
sick -headache,  mental  depression,  fatigue,  epilepsy,  etc.,  or  the  relation- 
ship between  dyspepsia  and  Eaynaud's  disease  or  paroxysmal  hsemo- 
globinuria. 

The  liver  is  subject,  also,  to  more  or  less  congestion  as  a  direct  or  in- 
direct result  of  circulatory  changes  produced  by  uric  acid. 

Blood. — The  blood  itself  is  changed  in  a  greater  or  less  degree  by  the 
action  of  uric  acid,  both  in  its  structure  and  its  nutritive  power.  The 
presence  of  uric  acid  in  the  blood  reduces  the  percentage  of  haemoglobin 
and  the  number  of  red  corpuscles,  thus  iDroducing  antemia.  Haig  was 
able  to  increase  or  diminish  the  amount  of  haemoglobin  and  the  number 
of  red  corpuscles  in  his  own  blood  from  day  to  day  by  the  administration 
of  iron  and  uric  acid  respectively.  The  amount  of  uric  acid  in  healthy 
blood  is  so  small  that  it  is  with  extreme  difficulty  that  it  can  be  detected. 
Garrod  has  demonstrated  the  fact,  however,  that  in  gout  the  blood  is  espe- 
cially rich  in  uric  acid,  and  has  found  as  high  as  0.175  parts  in  10,000,  and 
that  the  blood  is  especially  charged  with  it  just  prior  to  and  during  acute 
attacks,  but  that  it  is  always  present  in  chronic  gout. 

Eoberts  claims,  however,  that  uric  acid  as  such  is  never  found  in  the 


HEMATOGENIC    CALCIC    PERICEMENTITIS.  553 

blood  or  deposited  in  the  tissues,  but  that  as  normally  found  in  the  blood 
it  is  in  the  form  of  a  cxuadrurate,  a  compound  of  four  equivalents  of  uric 
acid  with  one  of  soda  or  potash.  This  quadrurate  is  an  exceedingly  un- 
stable compound,  and  under  especial  conditions  is  liable  to  be  decomposed 
into  biurate  and  uric  acid.  The  tophi  of  gout  consist  of  the  biurate,  but 
this  salt  is  almost  insoluble  in  serum ;  even  at  body  temperature  it  is 
dissolved  only  in  the  proportion  of  1  in  10,000.     (Levison.) 

The  tophi  are  formed  by  the  transformation  of  the  quadrurates  found 
in  the  blood  into  biurate  and  uric  acid,  which  gives  rise  to  the  deposition 
of  the  former  compound  in  various  tissues  of  the  body,  while  the  uric  acid 
is  eliminated  by  the  kidneys.  The  tophus  formed  from  this  crystalline 
deposit  of  sodium  biurate  "acts  passively  and  physically  as  a  foreign 
body  in  the  affected  tissue  or  organ."     (Luff.) 

Tunneclifife  and  Eosenheim*  combat  the  claim  of  Eoberts  of  the  ex- 
istence in  the  blood  of  uric  acid  in  the  form  of  quadrurates.  They  con- 
cede, however,  the  existence  of  two  classes  of  uric  acid  salts,  the  neutral 
(CsH^NA)^  and  the  acid  or  biurate  (C5H,N,03)HM.  They  conclude 
that  there  is  no  evidence  of  the  existence  of  quadrurates,  that  the  term 
should  be  abandoned,  and  that  any  theory  concerning  the  pathology  or 
treatment  of  gout  built  upon  this  assumption  requires  revision.  They 
think  the  existence  of  two  forms  of  uric  acid  (the  tautomeric  lactam  and 
lactim  forms)  may  explain  the  variation  in  the  physic  and  physiologic  be- 
havior of  this  acid  and  its  salts. 

Molliere  has  demonstrated  the  fact  that  uric  acid  and  the  urates  are 
antagonistic  to  the  development  of  the  i)yogenic  micro-organisms.  This 
exjjlains  the  reason  why  suppuration  so  seldom  occurs  about  tophi,  other  than 
those  located  upon  the  roots  of  teeth. 

Duckworth  found  the  red  corpuscles  diminished  and  the  leucocytes 
somewhat  increased  in  those  cases  already  affected  with  chronic  ne- 
phritis. 

The  amount  of  urea  found  in  the  blood  in  all  cases  associated  with 
granular  kidney  disease  doubtless  depends  upon  the  degree  of  renal  in- 
adequacy. 

Garrod  frequently  found  oxalic  acid  in  the  blood  of  gouty  subjects  ;  he 
believed  its  formation  occurred  principally  in  the  paroxysmal  stages,  and 
that  it  was  derived  by  oxidation  from  the  uric  acid. 

Ebstein  discovered  that  xanthin  and  hypoxanthin  were  formed  in  the 
blood  drawn  from  gouty  subjects  upon  exposing  it  in  a  warm  chamber, 
while  minute  quantities  of  uric  acid  disappeared. 

Secretions. — During  attacks  of  uric  acid  headaches  the  urine  and  the 
salivary  secretions  are  diminished,  the  mouth  and  tongue  often  being  dry 
and  parched  ;  in  chronic  gout  this  dry  parched  condition  may  last  for 
months,  but  in  acute  gout,  as  soon  as  the  excess  of  uric  acid  has  been 
eliminated  from  the  blood  by  the  administration  of  appropriate  remedies 
and  the  blood  has  assumed  a  normal  alkalinity,  the  secretion  of  ui-ine  and 
of  the  oral  fluids  becomes  for  a  time  relatively  excessive.     The  saliva  often 

*  London  Lancet,  June  16,  1900. 


554  OPERATIVE    DE^•TISTRY. 

shows  a  decided  acid  reaction  during  attacks  of  acute  gout,  and  usually 
gives  a  slight  acid  reaction  in  chronic  gout. 

The  amount  of  urea  excreted  in  the  urine,  according  to  Garrod,  is  about 
three  hundred  and  twenty  grains  per  diem.  Few  analyses  have  been  made 
of  the  excretion  of  urea  in  acute  gout,  but  such  as  have  been  recorded 
show  no  material  variation  from  the  normal  amount.  The  variation,  how- 
ever, such  as  exists,  bears  no  relation  to  the  amount  of  uric  acid  excreted 
at  the  same  time.  (Garrod.)  The  excretion  of  urea  is  diminished  just 
before  an  acute  attack  of  gout. 

Haig  gives  the  relation  of  urea  to  uric  acid  in  the  healthy  adult  as  one 
to  thirty-three,  and  says  that  in  uric  acid  headache  the  excretion  of  urea  was 
practically  unchanged,  while  that  of  uric  acid  fluctuated  greatly,  particu- 
larly in  relation  to  the  headaches.  Granville' s  examinations  of  the  urine 
of  gouty  subjects  corroborate  the  records  of  Haig. 

The  non-elimination  of  uric  acid  has  been  demonstrated  by  Garrod  to 
be  a  constant  and  marked  feature  of  paroxysmal  gout.  He  found  in  several 
cases  examined  in  reference  to  this  point  that  the  average  amount  was 
about  five  grains  less  than  the  normal,— 3.62  grains  as  against  8.569  grains. 
As  a  consequence  of  its  non-elimination  by  the  kidneys  there  is  an  in- 
creasing amount  stored  up  in  the  blood  or  the  tissues  of  the  body.  Haig 
is  of  the  opinion  that  much  of  this  may  be  stored  in  the  liver  and  the 
spleen. 

The  greatest  amount  of  excretion  in  health  occurs  during  the  alkaline 
tide  of  digestion.  (Eoberts. )  It  is  probable  that  the  excretion  of  uric  acid 
in  gout,  could  it  be  watched  from  hour  to  hour,  would  be  found  to  vary 
considerably.     (Duckworth.) 

Sansone,*  in  analyzing  one  thousand  grains  of  morning  urine  in  a  case 
of  acute  gout,  found  0.830  grain  of  uric  acid  5  in  one  of  chronic  gout,  0.120 
grain  ;  and  in  a  healthy  person,  0.250  grain. 

Gouty  individuals  often  suffer  from  gravel  and  calculosis  ;  oxaluria  is 
not  uncommon,  while  chronic  cystitis  and  urethritis  are  occasionally  ob- 
served in  elderly  persons  suffering  from  gout. 

Kidneys. — The  morbid  changes  which  are  found  in  the  kidneys  of 
gouty  subjects  present  the  ordinary  signs  of  granular  atrophy,  and  cannot 
be  distinguished  from  it  either  by  the  symptoms  or  by  an  examination  of 
its  anatomical  structure.  The  relationship  between  chronic  Bright' s  dis- 
ease and  certain  features  of  uricacidsemia  is  so  constant  that  many  observers 
have  been  led  to  believe  that  the  disease  was  caused  by  imperfect  meta- 
bolism of  the  albumins,  and  possibly  as  the  result  of  the  presence  of  an 
excess  of  uric  acid  in  the  system. 

Duckworth  t  is  of  the  opinion  that  the  gouty  habit  is  alone  the  potent 
factor  in  a  considerable  proportion  of  all  cases  of  interstitial  nephritis. 

Ord  and  Greenfield,!  in  a  large  series  of  cases  examined  with  the  object 
of  determining  the  i)resence  or  absence  of  renal  disease  in  gouty  subjects 


*  Beale,  Urine  and  Urinary  Deposits,  2d  edition,  p.  162. 

t  Treatise  on  Gout,  p.  101. 

X  Transactions  of  the  International  Medical  Congress,  1881. 


HEMATOGENIC   CALCIC   PEEICEMENTITIS.  555 

witli  uratic  deposits,  found  that  in  66^66  -per  cent,  of  the  hospital  cases  of 
gouty  affection  of  the  metatarso- phalangeal  articulation  of  the  great  toe 
there  was  a  definite  coexistence  of  contracted  granular  kidney,  and  that  in 
the  remaining  33.33  per  cent,  there  were  affections  of  the  kidneys  closely 
allied  thereto.  Out  of  ninety-six  cases  of  renal  disease,  there  were  eight 
and  possibly  nine  in  which  no  uratic  deposits  were  found  in  the  joints. 
Of  these,  two  were  examples  of  extreme  granular  contraction,  two  of 
marked  contracted  granular,  two  of  slightly  granular,  and  one  of  mixed 
granular  and  tubular  nephritis. 

Moore*  examined  forty-nine  cases  of  chronic  interstitial  nephritis  in 
males,  and  found  uratic  deposits  in  twenty-two.  In  another  series  of  six- 
teen females,  uratic  deposits  were  i^resent  in  five  cases. 

Continental  European  physicians  generally  hold  the  opinion  that  uratic 
deposits  are  constantly  found  in  the  contracted  kidneys  of  gouty  subjects, 
and  that  this  condition  is  somewhat  dependent  upon  the  presence  of  such 
deposits.  Duckworth's  studies  do  not  corroborate  this  opinion,  as  he  rarely 
found  such  deposits  in  the  kidneys  of  the  gouty. 

Liver. — -Haig  f  is  of  the  opinion  that  the  hypereemia  or  congestion  of 
the  liver  always  present  in  diabetes  is  due  to  the  same  cause  that  produces 
this  condition  of  the  liver  in  gouty  dyspepsia, — viz.,  the  presence  of  an 
excess  of  uric  acid  in  the  blood. 

Ord  X  has  pointed  out  the  fact  that  general  high  arterial  tension  may 
cause  an  excess  of  blood  in  the  liver,  and  thus  produce  diabetes ;  while 
Haig  §  has  shown  that  the  contracted  arterioles  and  arterial  tension  are  in 
a  direct  ratio  to  the  amount  of  uric  acid  circulating  in  the  blood,  and  the 
so-called  ' '  liver  attacks' '  he  looks  upon  as  uric  acid  storms,  almost  if  not 
quite  identical  with  attacks  of  uric  acid  headaches. 

Diabetes  seemingly  holds  a  close  relationship  to  gouty  conditions,  and 
must  be  dependent  upon  some  error  of  metabolism  for  its  existence.  Both 
of  these  conditions  present  many  similar  symptoms.  Latham  ||  observed 
"  that  diabetic  individuals  often  have  an  excess  of  uric  acid  in  their  urine 
and  suffer  from  neuralgic  pains  in  the  joints  and  limbs." 

Anderson^  observed  '^many  clinical  facts  which  seem  to  prove  that 
gouty  arthritis  and  diabetes  mellitus  are  in  certain  cases  merely  trans- 
formed symptoms  of  the  same  diathesis  ;  not  present  at  the  same  time,  but 
one  taking  the  place  of  the  other. ' ' 

Garrod  **  noticed  this  relationship,  and  says,  ' '  In  the  course  of  practice 
I  have  seen  several  cases  in ,  which  gouty  patients  have  become  affected 
with  saccharine  diabetes  or  glycosuria.  In  one  case  of  gout  of  twelve 
years'  standing,  in  a  gentleman  sixty  years  of  age,  diabetes  suddenly  de- 
veloped, and  for  a  period  of  over  four  years  there  were  no  more  attacks 

*  Loc.  cit. 

t  Uric  Acid  the  Causation  of  Disease,  p.  287. 
t  British  Medical  Journal,  1889. 
§  Uric  Acid  the  Causation  of  Disease,  p.  272. 
II  Ibid. 

t  British  Medical  Journal,  1886. 
**  Ophthalmic  Eeview,  1889. 


556  OPERATIVE    DENTISTRY. 

of  the  gout.  But  when  the  diabetes  was  checked  the  gout  very  soon  re- 
turned. ' ' 

Muscles. — Although  no  morbid  changes  have  been  observed  in  the 
muscular  system  in  uricacidsemia,  uric  acid  has  often  been  found  in  these 
structures. 

Uricacidsemia  produces,  probably  through  depression  of  the  nerve-cen- 
tres, a  disinclination  to  muscular  exercise  during  gouty  attacks  ;  this  re- 
sults in  a  deficient  circulation  in  the  muscles,  and  consequently  in  imper- 
fect elimination  of  the  waste  products.  The  tendons  become  involved  in 
association  with  the  joints  and  uratic  deposits  are  formed  in  them.  The 
muscles  often  become  the  seat  of  neuralgic  pains,  which  come  and  go  with 
other  gouty  symptoms. 

Nervous  System. — So  far  no  morbid  changes  have  been  discovered  in 
the  anatomical  structure  of  the  nerves  of  gouty  subjects  except  those  due 
to  cachexia  in  cases  of  long  standing.  Uratic  deposits  are  rarely  found  in 
the  nerve-tissues  or  their  investments.  Cornil  discovered  sodium  urate  in 
cerebro-spinal  fluid,  and  uratic  deposits  have  been  detected  in  a  few  in- 
stances in  the  cerebral  meninges. 

Albert  and  Ollivier  also  found  such  deposits  on  the  spinal  meninges. 
There  are  strong  clinical  reasons  for  believing  that  uricacidsemia  may  in- 
duce neuritis  in  almost  any  nerve-trunk,  with  motor,  sensory,  and  vaso- 
motor symptoms.  (Duckworth.)  Neuralgia  is  a  common  affection  in 
gouty  individuals.  Sciatica  and  general  myalgia  are  not  infrequently 
associated  with  other  gouty  symptoms,  and  the  writer  has  seen  several 
cases  of  trifacial  neuralgia  which  were  undoubtedly  due  to  gout. 

Skin. — The  circulation  and  the  nutrition  of  the  skin  are  often  markedly 
affected  by  the  i)i"esence  of  an  excess  of  uric  acid  in  the  system,  which  are 
manifested  during  uric  acid  headaches  in  a  pale,  cold  condition  of  the  sur- 
face of  the  skin,  and  in  certain  eruptive  diseases,  particularly  those  of  an 
ulcerative  character.  Among  the  diseases  allied  to  gout  may  be  mentioned 
erythema,  eczema,  urticaria,  psoriasis,  prurigo,  and  acne.  (Sarjou.)  Gold- 
ing-Bird  discovered  uric  acid  in  the  contents  of  the  vesicles  of  gouty 
eczema,  and  Begbie  found  it  in  the  bullse  of  pemphigus. 

Ulceration  of  the  skin  and  suppuration  often  accompany  the  exfolia- 
tion of  the  tophi  located  about  the  joints. 

Periosteum  and  Bone. — Uratic  deposits  frequently  occur  in  the  peri- 
osteum, resulting  in  inflammation  and  sometimes  in  exfoliation  or  extru- 
sion of  the  deposit.  On  the  other  hand,  inflammatory  symptoms  are  often 
present  in  and  about  the  epiphyses  of  the  long  bones,  particularly  of  the 
legs,  feet,  and  hands,  which  result  in  the  formation  of  nodes  or  of  a  true 
exostosis.  The  thickening  of  the  edges  of  the  alveolar  processes  so  often 
seen  associated  with  gingivitis  is  usually  the  result  of  chronic  irritation 
or  inflammation  of  the  periosteum  of  these  parts  due  to  the  gouty  diathesis. 

Nails. — These  tissues  are  dermal  appendages,  and  are  therefore  more 
or  less  profoundly  affected  by  all  diseases  which  have  a  predilection  for 
dermal  structures.  In  gouty  individuals  the  nails  are  observed  to  be  coarse, 
fibrous,  and  brittle,  striated,  fluted,  and  lined  vertically. 

After  an  acute  attack  of  gout  depressions  or  white  spots  or  lines  are 


H./EMATOGENIC    CALCIC    PERICEMENTITIS.  557 

observed,  forming  crescent-like  curves,  which  points  to  faulty  nutrition, 
and,  inasmuch  as  the  nail  requires  six  months  in  which  to  complete  its  de- 
velopment, these  defects,  by  their  position,  would  indicate  the  date  at 
which  the  illness  occurred,  just  as  faults  of  nutrition  are  recorded  upon 
the  enamel  of  the  permanent  teeth,  and  indicate  by  their  location  the  age 
of  the  individual  when  the  illness  occurred. 

Hair. — Senile  changes  occur  earlier  in  certain  tissues  than  in  others. 
These  tendencies  may  be  acquired  as  the  result  of  disease  or  of  debauchery, 
or  they  may  be  inherited  as  a  family  peculiarity,  or  an  evidence  of  de- 
generacy. 

This  tendency  to  early  senile  change  is  particularly  noticed  in  refer- 
ence to  the  hair.  In  some  individuals  the  hair  turns  gray  at  or  before  the 
thirtieth  year,  while  in  others  distinct  baldness  may  occur  at  an  equally 
early  age.  These  conditions  are  often  noticed  to  be  associated  with  the 
gouty  diathesis,  and  in  some  instances  are  no  doubt  dependent  upon 
uricacidsemia  as  a  primary  factor  in  its  causation.  "  The  hardened  tophace- 
ous matter  sometimes  found  in  the  sebaceous  glands  of  gouty  subjects  is 
composed  largely  of  urates.  About  fifty  per  cent,  of  it  is  sodium  and  cal- 
cium salts  of  uric  acid,  about  ten  per  cent,  sodium  chloride,  and  the  re- 
mainder calcium  phosphate  and  animal  matter."     (Duckworth.) 

Teeth. — The  character  of  the  teeth  in  gouty  subjects  is  remarkable  in 
that,  as  a  rule,  they  are  well  formed,  finely  developed,  having  strong,  hard 
enamel,  which  is  inclined  to  a  yellowish  color ;  they  have  strong  roots 
which  are  firmly  set  in  their  alveoli,  and  are  comparatively  immune  to 
caries.  After  middle  life  they  are  inclined  to  show  considerable  wear 
upon  the  morsal  surfaces.  This  has  been  thought  to  be  due  to  the  habit 
of  grinding  the  teeth  which  is  so  common  with  rheumatic  and  gouty  indi- 
viduals. This  habit  is  doubtless  formed  as  a  result  of  irritation  and  hyper- 
semia  of  the  pericementum  so  constantly  present  in  chronic  gout.  Neu- 
ralgic pains  are  also  frequently  present,  and  come  and  go  with  other  gouty 
symptoms.  The  teeth,  like  the  hair,  often  show  evidences  of  early  senile 
changes.  The  pericementum  and  the  alveolar  processes  atrophy  and  are 
resorbed,  while  the  gums  gradually  recede  as  the  former  conditions  pro- 
gress until  the  teeth  become  loose  and  fall  out.  These  changes  often  begin 
before  middle  life  is  reached,  and  when  these  tendencies  are  associated 
with  a  gouty  diathesis  the  destructive  process  becomes  most  marked  and 
rapid  in  its  progress. 

Exciting  Causes. — The  immediate  exciting  cause  of  gouty  pericemen- 
titis is  undoubtedly  the  presence  of  uratic  deposits  in  the  pericemental 
membrane.  This  morbific  material  plays  the  part  of  a  foreign  body,  and 
causes  mechanical  irritation  and  death  of  the  surrounding  cellular  ele- 
ments,— necrobiosis, — which  favors  the  further  deposition  of  the  urates. 
The  inflammatory  process  does  not  always  progress  to  the  suppurative 
stage,  as  infection  with  the  pyogenic  cocci  is  necessary  for  the  establish- 
ment of  a  septic  inflammation. 

Impaired  nutrition  of  the  pericementum  with  its  consequent  lowered 
vitality  is  also  an  important  factor  in  the  establishment  of  the  disease. 
These  conditions  are  to  be  found  as  a  result  of  severe  mechanical  strain 


558  OPERATIVE    DENTISTRY. 

from  over-exercise  of  the  teeth, — misuse^ — as  in  malocclusion  and  the  loss 
of  the  teeth,  which  places  the  strain  of  mastication  upon  a  few  remaining 
teeth  ;  in  insufficient  exercise  of  the  teeth — disuse — from  various  causes, 
as,  for  instance,  loss  of  occlusion,  the  constant  use  of  soft,  pulpy  foods 
which  require  little  mastication  to  comminute  their  substance  ;  overcrowd- 
ing of  the  dental  arch ;  traumatic  injuries  consequent  upon  wedging,  mal- 
leting,  changing  the  position  of  certain  teeth  in  the  process  of  regulating, 
and  other  similar  procedures.  The  unskilful  or  immoderate  use  of  the 
tooth-pick,  fioss-silk,  and  the  toothbrusli  may  occasionally  induce  con- 
ditions of  irritation  which  impair  the  nutrition  of  the  pericemental 
membrane. 

Varieties. — ^In  gouty  pericementitis  two  forms  of  inflammation  may 
be  observed, — one  which  produces  a  new  growth  of  cementum,  or  hyper- 
cementosis,  and  another  which  results  in  a  deposition  of  calcic  material 
combined  with  sodium  biurates  from  the  elements  of  the  blood.  The 
former  variety  has  already  been  described  in  the  preceding  chapter  on 
^'Pericementitis."  The  latter  variety  is  that  condition  which  has  been 
classed  by  Peirce,  Darby,  Burchard,  Jack,  and  others  as  gouty  pericemen- 
titis, and  which  the  writer  has  described  as  a  local  manifestation  of  the 
gouty  diathesis,  in  which  tophi  are  formed  within  the  pericementum,  and 
upon  the  surface  of  the  cementum  in  closed  pockets,  and  in  various  loca- 
tions more  or  less  remote  from  the  cervix  and  at  the  apex.  '■ '  These  tophi 
are  composed  of  sodium  and  calcium  biurates,  free  uric  acid^  and  calcium 
phosphate,  as  has  been  demonstrated  by  careful  analysis."     (Peirce.) 

The  manner  in  which  these  tophi  are  formed  within  the  pericementum 
is  as  yet  an  unsolved  proposition,  although  various  theories  have  been 
advanced  in  explanation  of  the  process. 

Pathology  and  Morbid  Anatomy. — Gouty  deposits  are  met  with  only 
in  tissues  which  have  a  scanty  vascular  supply,  or  in  which  the  circulation 
is  more  or  less  sluggish.  Tophi  are  most  frequently  found  in  the  tissues 
which  surround  the  joints,  like  the  cartilages,  aponeuroses,  and  perios- 
teum. The  small  joints  are  most  often  affected.  The  relation  of  the  teeth 
with  the  alveolar  process  is  that  of  gomphosis,  a  species  of  joint  termed 
the  dento-alveolar  articulation,  and  the  tissue  which  intervenes  between 
the  cementum  and  the  bone  is  the  pericementum,  a  dense  fibrous  structure 
having  a  scanty  vascidar  supply  as  compared  with  the  somewhat  analogous 
structure,  the  periosteum.  Under  certain  conditions  exostosis  and  nodular 
formations  occur  upon  the  surfaces  of  the  bones  as  a  result  of  the  irritation 
of  the  periosteum  from  the  presence  of  the  gouty  poison  in  the  blood  and 
its  deposition  within  the  tissues.  The  same  condition  has  already  been  re- 
ferred to  as  occurring  uj)on  the  roots  of  the  teeth  from  the  same  cause. 
There  would  seem  to  be,  therefore,  no  good  reason  for  objecting  to  the  con- 
clusion which  has  been  reached  by  so  many  able  observers, — viz.,  that  the 
deposits  formed  upon  the  roots  of  the  teeth  primarily  in  the  pericementum 
and  in  closed  pockets  which  could  not  have  been  at  any  time  in  commu- 
nication with  the  oral  cavity,  must  have  been  deposited  from  the  blood ; 
and,  inasmuch  as  tophi  are  also  found  in  the  jjeriosteum  surrounding  a 
joint,  the  inference  is  fair  that  similar  tophi  may  be  formed  in  the  peri- 


HEMATOGENIC    CALCIC    PERICEMENTITIS.  559 

cementum  surrouiiding  the  root  of  the  tooth  and  forming  the  "joint"  with 
the  alveolar  process. 

Formation  of  Deposits. — In  relation  to  the  manner  or  modus  operandi 
of  the  formation  of  these  tophi,  Mordhorst  *  says,  '  '■  The  granular  urate  is 
always  the  precursor  of  the  crystalline  form,  and  in  the  bodyflnids  the 
uric  acid  circulates  in  the  form  of  invisible  granules  of  sodium  urate. 
Gouty  deposits  are  only  met  with  in  non- vascular  tissues,  and  as  acids 
and  acid  salts  diffuse  more  rapidly  and  readily  than  alkalies  and  alkaline 
salts,  we  must  suppose  that  the  alkalinity  of  the  non-vascular  tissues  is 
less  than  that  of  ,the  blood.  Hence  if  a  transudate  almost  saturated  with 
urate  enters  such  a  less  alkaline  tissue  the  solution  becomes  supersaturated 
and  granular  urate  is  precipitated  in  the  tissue,  the  precipitation  being 
favored  by  such  additional  factors  as  lowered  temperature  or  increased 
concentration  of  the  fluids  of  the  tissue.  The  precipitation  of  the  granular 
urate  in  the  spaces  of  the  interstitial  tissue  and  in  the  lymph-channels  is 
the  cause  of  the  various  phenomena  of  gout.  In  the  course  of  time  the 
urate  deposited  becomes  converted  into  acicular  crystals  of  sodium  biurate, 
or  under  favorable  conditions  may  be  redissolved  and  disappear,  and  with 
them  disappear  the  lesions  to  which  they  gave  rise."  If  this  theory  is 
correct  it  explains  why  constitutional  treatment,  which  aims  to  redissolve 
and  eliminate  the  biurates,  often  mitigates  the  severity  and  sometimes 
cures  certain  cases  of  gouty  pericementitis. 

Ebstein  t  believed  that  in  gout  uric  acid  is  formed  in  excess  in  the  body, 
and  that  hyper- j)roduction  also  takes  place  in  regions  which  ordinarily 
do  not  produce  uric  acid,  as,  for  example,  the  bone-marrow,  the  carti- 
lages, etc. 

When  the  blood  and  the  lymph  are  overcharged  with  uric  acid  it  may 
act  as  a  chemic  poison,  causing  morbid  processes  in  the  tissues  and 
giving  rise  even  to  necrobiotic  changes ;  when  these  have  reached  a  cer- 
tain degree  the  biurate  is  deposited  in  the  necrotic  parts  of  the  structures, 
whereas  such  deposition  is  never  found  elsewhere. 

Klemperer]:  is  of  the  opinion  that  "the  phenomena  of  gout  cannot  be 
explained  by  a  mere  crystallization  of  urates  from  the  blood,  or  by  the 
production  of  necrotic  changes  due  to  its  ]3resence  in  the  circulation, 
seeing  that  in  other  conditions  in  which  uric  acid  is  present  in  excess  in 
the  blood,  such  as  leucocythsemia  and  chronic  nephritis,  neither  uratic 
deposits  nor  necrosis  of  cartilage  are  met  with.  Some  unknown  sub- 
stances produce  in  gouty  persons  inflammation  and  necrotic  changes  in 
various  tissues,  and  the  necrosed  tissues  possess  the  power  of  attracting 
to  themselves  the  excess  of  uric  acid  in  the  blood,  while  the  chemic 
affinity  of  the  necrosed  parts  for  uric  acid  prevents  the  deposits  from  being 
redissolved  by  the  blood. 

The  writer  has  called  attention  to  the  fact  §  that  rheumatic  and  gouty 

*  Zeits.  f.  klin.  Med.,  p.  65,  1897,  from  Sarjou. 
t  Nature  u.  Behandlung  d.  Greht.,  from  Sarjou. 
X  Deutsche  med.  Woch.,  xxi.  p.  655,  1895,  from  Sarjou. 

§  The  Eheumatic  and  Gouty  Diathesis,  as  manifested  in  the  Peridental  Membrane^ 
Journal  of  the  American  Medical  Association,  1891. 


560  OPEEATIVE    DENTISTRY. 

conditions  are  often  observed  in  the  form  of  inflammation  of  the  peridental 
membrane  as  a  primary  symptom  of  an  approaching  acute  attack  of 
articular  rheumatism  or  of  gout,  and  that  many  times  this  condition  is 
the  only  local  expression  of  the  diathesis.  Tliis  fact  has  been  overlooked 
by  the  general  practitionei",  and  consequently  no  mention  is  made  of  this 
symptom  of  gout  and  rheumatism  in  works  upon  these  diseases. 

The  fact  of  the  acute  susceptibility  of  the  peridental  membrane  to  the 
presence  of  the  materies  morM  of  these  diseases  is  a  clinical  fact  which  has 
only  been  recognized  by  dental  specialists  during  the  last  few  years.  In- 
flammation of  tBe  pericementum  as  a  manifestation  of  the  gouty  diathesis 
is  proved  by  the  relief  obtained  from  the  exhibition  of  therapeutic  reme- 
dies which  eliminate  the  uric  acid  from  the  system. 

In  the  preceding  x^ages  it  has  been  shown  upon  the  best  authority  that 
gout,  which  is  primarily  a  joint  affection,  may  also  exist  in  certain  dis- 
orders of  the  blood-vessels,  the  circulation,  the  blood,  tlie  secretions,  the 
muscles,  the  kidneys,  the  liver,  the  stomach,  the  nervous  system,  the  skin, 
the  periosteum,  the  bones,  the  hair,  the  nails,  etc.  The  effects  upon  these 
tissues  and  organs  of  the  presence  in  the  system  of  an  excess  of  uric  acid 
are  peculiar  to  each  particular  kind  of  tissue  and  to  the  function  of  the 
organ,  the  variety  of  the  manifestations  being  as  numerous  as  the  tissues  and 
organs  affected. 

In  the  periosteum,  the  character  of  whose  tissue  most  nearly  approaches 
that  of  the  j)ericementum,  these  manifestations  are,  as  already  noticed,  of 
two  forms,  one  chronic  in  character,  which  results  in  the  formation  of  nodes 
and  exostoses,  and  the  other  acute,  in  which  uratic  deposits  are  present. 

These  deposits  may  be  in  the  form  of  defined  concretions,  when  they  are 
readily  detected  ;  but,  as  pointed  out  by  Mordhorst,  they  may  be  deposited 
in  the  form  of  invisible  granules  and  later  converted  into  acicular  crystals 
of  sodium  urate,  which  still  might  be  so  small  as  to  escape  detection. 

The  deposits  which  are  formed  uj)on  the  roots  of  the  teeth  in  gouty 
pericementitis  are  thin,  greenish-colored,  hard  scales  composed  of  urates 
of  sodium,  calcium,  etc.,  which  are  very  adherent  and  often  require  con- 
siderable force  to  dislodge  them.  These  concretions  may  be  located  upon 
any  aspect  of  the  root,  but  most  frequently  upon  the  lingual  and  approxi- 
mal  surfaces  towards  the  apex. 

Uratic  deposits  upon  the  roots  of  the  teeth  are,  however,  not  so  common 
as  might  be  supposed  from  the  literature  upon  the  subject.  All  calcic  de- 
posits of  dark  color  found  upon  the  roots  of  the  teeth  are  by  no  means  evi- 
dence of  a  gouty  condition  of  the  system.  Such  deposits  which  have  been 
exposed  to  the  fluids  of  the  mouth  and  constantly  bathed  with  pus  will 
always  be  dark  colored  and  have  the  appearance  of  being  formed  from 
tiny  globular  masses,  a  condition  usually  observed  in  the  concretions 
which  have  accumulated  upon  the  surfaces  of  foreign  bodies,  bullets,  frag- 
ments of  metal,  etc.,  which  have  been  buried  in  the  tissues  and  bathed  in 
pus  for  a  considerable  period.  This  same  form  of  deposit  is  found  upon 
the  roots  of  devitalized  teeth  which  penetrate  the  floor  of  the  antrum  of 
Highmore,  and  which,  by  inducing  septic  infection  of  this  sinus  through 
the  agency  of  a  putrefying  pulp,  has  caused  empyema. 


H:^MATOGENIC    CALCIC    PERICEMENTITIS.  561 

Eoots  of  teeth,  wliicli  have  been  forced  into  the  antrum  in  an  effort  to 
extract  them,  teeth  which  have  erupted  into  this  sinus,  and  foreign  bodies 
which  have  been  introduced  by  traumatism  invariably  induce  suppuration. 
These  bodies  after  a  time  become  covered  with  concretions  which  have  a 
dark-green  color  and  a  roughened  surface  like  that  just  described. 

The  variety  of  deposit  found  upon  foreign  bodies  and  the  roots  of  teeth 
seems  to  be  peculiarly  and  almost  invariably  the  result  of  the  supiDurative 
process,  the  concretion  being  calcic  material,  and  rarely  responding  to  the 
murexide  test  for  uric  acid. 

Concretions  which  are  identically  the  same  are  frequently  found  upon 
the  "roots  of  the  teeth  in  pyorrhoea  alveolaris  in  its  later  stages,  when  the 
roots  of  the  teeth  have  been  bathed  in  pus  and  the  oral  secretions  for 
months,  and  the  deposit  constantly  accumulating  until  the  tooth  is  ex- 
foliated. Cases  of  this  character  when  tested  for  uric  acid  usually  give 
negative  results,  and  yet  it  is  largely  this  class  of  cases  which  have  been 
selected  for  chemical  analysis  with  the  view  of  discrediting  the  theory 
that  uric  acid  plays  an  important  part  in  producing  that  peculiar  form  of 
pericementitis  accompanied  with  suppuration  which  has  been  designated 
"gouty  pericementitis." 

The  deposits  in  true  gouty  pericementitis  are  formed  in  tiny  islands  of 
irregular  outline,  and  in  the  form  of  thin  scales  with  smooth  surface,  dark- 
green  in  color,  and  very  firmly  adherent  to  the  surface  of  the  cementum. 
These  deposits  are  doubtless  formed  in  the  pericementum  through  the 
agency  of  some  unknown  substances,  as  suggested  by  Klemperer,  which  in 
gouty  persons  produce  inflammation  and  necrobiotic  changes,  while  the 
necrosed  tissues  possess  the  power  of  attracting  to  themselves  the  excess 
of  uric  acid  in  the  blood.  The  chemic  affinity  of  the  necrosed  tissues  for 
uric  acid  also  prevents  them  from  being  redissolved  by  the  blood  when  it 
has  assumed  its  normal  alkalinity. 

The  i^resence  of  these  deposits  uJDon  the  root  of  the  tooth  produces 
symptoms  of  irritation  of  the  pericemental  membrane.  Sooner  or  later 
this  develops  inflammation  and  the  formation  of  an  abscess  at  the  location 
occupied  by  the  deposit,  which  may  point  directly  through  the  gum  or 
burrow  along  the  side  of  the  root  and  discharge  at  the  cervix.  These 
abscess  pockets,  as  the  writer  pointed  out  some  years  ago,  have  no  com- 
munication with  the  oral  secretions  until  pointing  takes  place,  and  this 
fact  has  been  demonstrated  over  and  over  again  by  the  most  thorough  and 
painstaking  examinations.  The  infection,  therefore,  which  induced  the 
suppurative  process  could  not  have  occurred  from  the  mouth, — unless  the 
suggestion  of  Black  *  is  correct,  that  ' '  infection  may  possibly  take  place 
through  the  glandular  structures  which  he  has  discovered  in  the  pericemen- 
tum,"— but  most  likely  it  has  come  through  the  avenue  of  the  circulation. 
For  this  reason  the  writer  is  of  the  opinion  that  the  gouty  deposits  in  the 
pericemental  membrane  do  not  immediately  cause  suppuration,  and  that 
the  presence  of  the  pyogenic  cocci  in  the  blood-current  are  necessary  to 
establish  this  process. 

*  Dental  Review,  vol.  xi.  p.  258. 
36 


562  OPEEATILE    DENTISTRY. 

The  character  of  the  inflammation  which  is  primarily  established  in 
these  cases  is  always  acute,  the  abscess  usually  pointing  in  from  twenty- 
four  to  forty-eight  hours.  The  presence  of  the  concretion  is  readily  demon- 
strated by  laying  the  abscess  open,  excavating  the  pus,  and  packing  the 
cavity  with  a  tiny  strip  of  gauze  or  a  pledget  of  cotton  for  a  few  hours  or 
overnight.  On  removing  the  dressing  and  irrigating  the  cavity  the  deposit 
is  brought  to  view.  This  would  seem  to  settle  the  question  of  the  deposit 
being  the  cause  of  the  irritation^  and  that  it  was  not  formed  as  a  result  of  the 
suppurative  process,  as  this  is  acute  and  of  such  brief  duration  that  a  con- 
cretion of  this  character  could  not  be  formed  in  so  short  a  time.  Neither 
is  it  possible  for  the  concretion  to  have  been  deposited  from  the  oral  secre- 
tions, for  no  communication  existed  between  them  until  the  abscess  pointed. 

Symptoms  and  Diagnosis. — The  first  symptom  of  gouty  perice- 
mentitis is  soreness  and  elongation  of  the  tooth,  followed  in  a  few  hours  in 
the  suppurative  variety  by  swelling  of  the  gum  either  upon  the  buccal  or 
lingual  aspect  at  locations  varying  from  midway  of  the  length  of  the  root 
to  the  apical  region.  The  swelling  is  accompanied  by  considerable  pain 
of  a  throbbing  character.  At  the  end  of  twenty-four  to  forty-eight  hours 
fluctuation  may  be  felt,  and  upon  opening  the  swelling  pus  escapes.  The 
early  stages  of  the  disease  so  closely  simulate  septic  apical  pericementitis 
and  dento-alveolar  abscess  that  it  may  readily  be  mistaken  for  these  affec- 
tions. It  may,  however,  be  differentiated  from  them  (1)  by  the  fact  that 
the  teeth  affected  are  usually  vital ;  (2)  that  the  swelling  is  generally  con- 
fined to  the  gum  over  the  affected  tooth,  and  rarely  extends  to  the  overlying 
soft  tissues  ;  (3)  the  character  of  the  pain  is  not  so  severe  nor  the  duration 
of  the  attack  so  prolonged  ;  (4)  the  abscess  is  limited  to  a  comparatively 
small  area,  and  there  is  usually  no  communication  between  the  abscess- 
cavity  and  the  apical  space.  The  peculiarity  of  this  variety  of  abscess  is 
that  it  is  formed  about  a  tophus  located  upon  the  surface  of  the  cementum, 
and  that  until  the  abscess  ruptures  there  is  no  communication  between  it 
and  the  cavity  of  the  mouth. 

Prognosis. — The  i^rognosis  will  depend  largely  upon  the  success  of  the 
constitutional  treatment  in  eliminating  the  uric  acid  from  the  system  and 
preventing  its  excessive  formation  afterwards,  and  also  in  the  thorough- 
ness with  which  the  irritating  concretions  are  removed  from  the  roots  of 
the  teeth.  Marked  and  almost  immediate  relief  is  frequently  obtained  by 
vigorous  general  therapeutic  measures  addressed  to  the  elimination  of  the 
quadrurates.  A  favorable  prognosis  cannot  be  hoped  for,  however,  by 
constitutional  treatment  alone.  Local  treatment  must  be  instituted  for  the 
removal  of  the  concretions,  and  this  must  be  etfectually  done  if  the  sup 
purative  process  is  to  be  controlled. 

Because  one  or  more  teeth  have  been  attacked  by  this  disease  it  does 
not  follow  that  all  of  the  teeth,  or  even  any  others,  will  be  so  affected. 
The  disease  usually  manifests  itself  in  those  teeth  which  have  suffered  in- 
jury of  some  form  to  the  i)ericementum  whereby  its  resistive  power  has 
been  weakened.  Constitutional  measures  which  have  for  their  object  the 
control  of  the  disease  by  restricted  diet  and  j)roper  exercise  must  be 
rigidly  carried  out  if  the  desired  object  is  to  be  gained.     Half-way  meas- 


HEMATOGENIC    CALCIC    PERICEMENTITIS.  563 

ures  are  worse  tlian  useless.     The  prognosis  will  be  unfavorable  if  the  irri- 

htlT  ""tT"^'"'  ""''  "'*  '"^^^"^  ^"  ^^"  constitutional  dyscrasia  com- 
bated.    Such  cases  are  marked  by  chronic  inflammation  and  suppuration 
loosening  and  extrusion  of  the  tooth,  which  may  also  turn  upon  its  aS 


Fig.  633. 


Fig.  634. 


After  Dr.  George  S.  Allan. 


After  Dr.  George  S.  Allan. 


and  form  a  wide  separation  from  its  neighbor  on  one  side      Dr  Georo-e  S 
Allan  presented  to  the   ^w  Jersey   State  Dental   Society  casts  taken 
from  the  mouth  of  a  gentlemen  which  represent  these  features  of  the 
disease.      Fig.   633  represents  the  denture  before  the  disease  appeared  j 

Fig.  635. 


After  Dr.  George  S.  Allan. 

Fig  634  Shows  the  condition  one  year  later;  Fig.  635  exhibits  the  case 
with  the  tooth  permanently  elongated  after  treatment,  while  Fig.  636  shows 
the  appearance  of  the  denture  after  the  tooth  had  been  shortened  by  grind- 
ing to  match  its  fellow.  .y  s    "^ 

Fig.  636. 


After  Dr.  George  S.  Allan. 

Treatment— The  treatment  of  gouty  pericementitis  to  be  effective 
must  be  applied  to  both  the  local  and  the  constitutional  conditions 

Local  Treatment.— The  treatment  of  the  local  conditions  compre- 
hends the  removal  of  the  deposits,  the  control  and  suppression  of  the  in- 
flammatory symptoms,  the  stimulation  of  the  healing  process,  the  institu- 
tion of  thorough  and  vigilant  oral  hygienic  measures,  and  the  support  of 


564  OPEEATIVE    DENTISTRY. 

the  teeth  to  obtain  surgical  rest,  as  already  described  under  the  head  of 
ptyalogenic  calcic  pericementitis. 

The  tophus  may  be  readily  discovered  by  opening  the  abscess  by  means 
of  a  curved  incision,  lifting  the  flap,  and  packing  the  cavity  for  a  few  hours 
with  gauze  or  cotton. 

After  removing  the  concretion  the  cavity  should  be  irrigated  with  an 
antiseptic  solution,  the  flap  brought  into  apposition  and  retained  until 

healed  by  a  couple  of  sterilized   horse-hair  sutures. 

Fig.  637.  ^-pj^^  ^3^^^ 

/\i_ Constitutional  Treatment. — The   constitutional 

iilllllr  iy        ^  treatment  of  gouty  pericementitis  is  that  which  should 

I  IF  jp\!4  jiliiiliii _B  be  prescribed  for  gout  in  general.    Any  regime  which 

(^^mi " "^^ J!l \\l T ^  ^"^^  prevent  the  accumulation  of  an  excess  of  uric 

/     IP^  ^  ^^^^  ^^  ^^  blood  or  effect  its  elimination  when  formed 

I      lili|-      S    II  ^^  produce  beneficial  results  in  gouty  pericementitis. 

^~n        r— ""^^  Preventive  Treatment. — Prophylactic  treatment 

Gum  turned  aside,  show-  iu  gouty  Conditions  of  the  system  should  be  instituted 

ing  underlying  condition  in  ^^.    euough  iu  thosc  individuals  who  have  inherited 

a  ease  of  pyorrlioea  alveo-  ''  ^ 

laris.  A,  cervix  of  tooth ;  the  prcdisposition  to  Ward  off  a  first  attack  ;  or  after 
B,  thickened  and  degener-  ^j^^  development  of  the  discasc  to  prevent  or,  at  least, 

ated  pericementum ;  C,  al-  ' 

veoiar  process  thinned  and  to  retard  the  recurrence  of  any  future  attack.  This 
irregularly  absorbed ;  D,  j^ay  be  accomplished  by  a  restricted  diet  and  hy  proper 
amount  of  out-door  exercise. 

Gouty  individuals  and  those  with  the  inherited  tendency  to  the  affec- 
tion should  eschew  all  food  which  contains  much  nuclein,  as  this  substance 
tends  to  increase  the  percentage  of  uric  acid  in  the  blood.  Sweetbreads, 
liver,  brains,  kidneys,  and  meat  extracts  all  contain  large  quantities  of 
nuclein,  hence  are  contraindicated  in  gouty  subjects.  Eggs  are  admissi- 
ble, as  they  contain  no  nuclein,  but  instead  paranuclein,  which  during  the 
metabolism  of  digestion  and  assimilation  is  not  converted  into  uric  acid. 
Meat  and  fish  contain  proteids,  but  as  this  substance  is  not  decomposed  to 
form  uric  acid,  a  moderate  amount  of  these  foods  may  be  taken.  Sarjou 
places  the  daily  allowance  at  two  hundred  grammes,  a  trifle  over  seven 
ounces.  A  larger  quantity  he  thinks  would  overtax  digestion  and  the 
eliminative  powers  of  the  kidneys. 

Haig*  says,  "The  uric  acid  taken  in  the  food  constitutes  the  bulk  of 
the  uric  acid  eliminated.  The  avoidance  of  animal  food  containing  xan- 
thin  compounds  or  uric  acid,  and  also  tea,  coffee,  and  cocoa,  whose  alka- 
loids are  similar  xanthin  compounds,  will  gradually  eliminate  any  excess 
of  uric  acid  in  the  system." 

Kolisch  t  would  eliminate  every  influence  which  might  tend  to  irritate 
or  injure  the  kidneys,  and  he  regards  alcohol  and  foods  which  might  in- 
crease the  amount  of  the  irritating  alloxins  as  especially  harmful  in  this 
direction.  Among  the  latter  he  classes  flesh  rich  in  cellular  elements, 
while  muscle,  particularly  if  it  has  been  boiled,  he  regards  as  permissible. 

*  British  Medical  Journal,  March,  1897. 
t  Wiener  klin.  Woch.,  No.  45,  1895. 


H-^MATOGENIC   CALCIC    PERICEMENTITIS.  565 

Milk  and  eggs  he  thinks  are  free  from  objection,  as  the  nucleins  (para- 
nuclein)  which  they  contain  do  not  form  alloxins.  The  carbohydrates  and 
fats  he  thinks  are  allowable,  and  vegetables, — salads  and  greens, — except- 
ing asparagus,  are  useful. 

]!«3"othnagel  *  recommends  as  a  diet  for  gouty  patients  plenty  of  fresh 
vegetables,  fruits,  and  starchy  food,  small  quantities  of  meat,  and  the 
exclusion  of  sugars. 

Laquerf  recommends  fatty  milk,  according  to  Gartner's  formula,  as  a 
suitable  diet  for  all  cases  of  gout.  He  thinks  the  administration  of  milk 
increases  the  excretion  of  xanthin  bases  and  reduces  that  of  uric  acid.  An 
increased  quantity  of  water  in  the  diet  increases  the  alloxin  bodies  (uric 
acid  and  xanthin  bases)  in  healthy  persons. 

Wood  X  thinks  that  milk  probably  suits  the  largest  number  of  gouty 
patients,  but  believes  there  is  no  diet  for  gout.  The  diet  must  be  adapted 
to  the  individual  case,  l^evertheless,  in  a  large  majority  of  cases,  sugar 
and  starches  must  be  cut  off.  But  in  spare  gouty  subjects  a  farninaceous 
diet  may  be  essential. 

The  ingestion  of  large  quantities,  three  to  four  pints  or  more,  of  fluids, 
such  as  milk  and  pure  water,  especially  skim-milk  and  buttermilk,  and  dis- 
tilled water  or  lithia  water,  is  to  be  recommended,  to  favor  the  free  action 
of  the  kidneys  and  to  stimulate  the  elimination  of  the  waste  products. 

Alkaline  waters  were  at  one  time  very  widely  recommended  in  gout 
and  rheumatism,  but  experience  has  shown  that  when  the  waters  contain 
soda  in  any  appreciable  amount  their  ingestion  is  liable  to  accelerate  the 
deposition  of  the  biurate  and  thus  provoke  an  attack  of  gout.     (Sarjou.) 

Alcohol  as  a  beverage  in  whatever  form  should  be  eschewed  by  gouty 
subjects,  as  numerous  observations  have  proved  its  pernicious  effects. 
Alcohol  increases  the  formation  of  uric  acid  and  favors  the  deposition  of 
the  urates.  The  pernicious  effect  of  alcoholic  beverages  in  these  cases  is 
thought  to  be  due  to  the  incomplete  process  of  fermentation  by  which  they 
are  produced. 

The  light  wines  are  the  least  injurious,  and  Bordeaux,  Mosel,  and  Rhein 
wines  may  be  taken  in  small  quantities ;  but  the  stronger  wines,  like 
sherry,  port,  and  champagne,  and  ale,  porter,  and  stout,  should  never  form 
a  part  of  the  diet  of  a  gouty  individual.  In  certain  persons  a  glass  of  any 
of  these  beverages  would  be  sufficient  to  provoke  an  attack  of  acute  gout 
of  the  great  toe,  a  gouty  sick  headache,  or  an  attack  of  iDyorrhcea  alveolaris. 

Exercise. — Exercise  to  be  beneficial  as  a  prophylactic  measure  in 
gouty  conditions  should  be  regular,  and  of  such  a  vigorous  nature  as  to 
.  bring  a  healthy  glow  to  the  surface  of  the  body  and  stimulate  the  emunc- 
tory  organs.  Such  exercise  should  be  taken  out  of  doors,  and  may  consist 
of  walking,  riding,  cycling,  or  playing  tennis,  golf,  cricket,  base-ball,  etc. 
"Over-exercise  is  harmful  on  account  of  the  tendency  to  increase  the 
alloxin  productions. ' '     (Kloisch. ) 


*  Internat.  klin.  Rundschau,  February  14,  1892. 
t  Berliner  klin.  Woch. ,  September  7,  1896. 
I  New  York  Medical  Eecord,  July  10,  1897. 


566  OPERATIVE   DENTISTEY. 

Treatment  of  Acute  Attacks. — In  the  systemic  treatment  of  acute 
attacks  of  gout,  it  is  obvious  that  the  treatment  should  be  directed  towards 
the  elimination  of  the  excess  of  uric  acid  and  its  compounds  which  are 
present  in  the  blood  and  tissues  of  the  body. 

Until  quite  recently  alkalies  and  alkaline  combinations  have  been  the 
most  generally  favored  remedies  in  the  treatment  of  gouty  conditions.  Of 
these  combinations  the  most  generally  employed  were  the  carbonates  and 
phosphates  of  sodium  and  potassium  and  the  carbonate  of  lithium.  The 
use  of  these  remedies  was  based  upon  the  supposition  of  an  acid  condition, 
or  rather  a  lessened  alkalinity  of  the  blood,  and  that  by  the  ingestion  of 
alkaline  remedies  the  alkalinity  of  the  blood  would  be  increased  and  its 
power  to  dissolve  uric  acid  and  prevent  the  deposition  of  the  biurate 
greatly  augmented.  The  experiments  of  Roberts  have  proved  these  sup- 
positions to  have  been  based  upon  false  premises.  In  the  first  place,  there 
is  no  such  thing  as  an  abnormal  acidity  of  the  blood  in  gout,  and,  second, 
"the  addition  of  the  carbonates  and  phosphates  of  alkalines  to  blood-serum 
impregnated  with  uric  acid  did  not  retard  the  precipitation  of  biurate ; 
the  alkalines  are  consequently  without  power  to  prevent  the  formation  of 
uratic  deposits,  and  the  salts  of  soda  may  even  prove  directly  pernicious 
when  taken  in  large  doses."     (Levison.) 

The  alkaline  lithiu  mcompounds — the  citrate  and  carbonate — have  been 
quite  extensively  employed  in  the  milder  cases  of  gout,  the  subacute  and 
chronic  forms,  and  with  seeming  good  results.  Tartarlithine,  lithium 
bitartrate,  and  alkalithia,  prepared  in  five-grain  tablets,  are  very  conve- 
nient for  use.  They  may  be  prescribed,  one  tablet  dissolved  in  a  glass  of 
hot  water  three  or  four  times  per  diem. 

Of  the  mineral  springs  the  Saratoga,  Vichy,  Buffalo  lithia,  Carlsbad, 
and  Apollinaris  are  probably  the  best.  Among  the  prepared  waters  the 
ozonated  lithia  is  the  best.  Waters  of  this  character  to  be  of  real  benefit 
should  be  drunk  in  large  quantities,  so  as  to  increase  the  excretion  of  urine 
to  from  three  to  five  pints  daily. 

Among  the  other  remedies  which  are  employed  to  eliminate  the  waste 
products  and  check  the  excessive  formation  of  uric  acid  are  colchicum, 
guaiacum,  calomel,  and  the  salicylate  of  sodium. 

In  order  to  check  the  excessive  production  of  uric  acid  it  is  necessary 
to  promote  liver-metabolism  and  relieve  the  congested  state  of  the  portal 
system.  These  results  may  be  secured  by  regulating  the  diet  and  daily 
regimen  and  the  administration  of  colchicum.  This  drug  is  usually  ad- 
ministered as  wine  of  colchicum,  in  doses  of  twenty-five  minims  three 
times  per  diem.  Or  it  may  be  combined  with  three  to  five  minims  of  the 
tincture  of  aconite.  Colchicum  must  be  used  with  circumspection,  as  it  is 
liable,  if  administered  in  large  doses,  or  its  use  long  continued,  to  produce 
nausea  and  diarrhoea.  For  these  reasons  the  use  of  the  drug  should  not  be 
continued  in  any  case  for  more  than  four  to  six  days.  Colchicum  not  only 
relieves  the  torpid  condition  of  the  liver  and  the  portal  system,  but  it 
relieves  the  severe  pain  of  gout  better  than  any  other  drug.  Its  mode  of 
action,  however,  is  obscure. 

Guaiacum  also  stimulates  hepatic  metabolism  and  checks  excessi^•e  uric 


H-^MATOGENIC   CALCIC   PERICEMENTITIS.  567 

acid  formation.  It  also  stimulates  the  kidneys,  and  assists  them  to  elimi- 
nate the  uric  acid  formed  in  them,  and  prevents  its  absorption  by  the  blood. 
This  drug-  is  usually  prescribed  in  the  form  of  the  tincture  gaaiaci ;  dose, 
one  to  two  fluidrachms  three  times  per  diem,  administered  preferably  in 
milk. 

Calomel  is  administered  for  the  same  purpose,  but  the  best  results  are 
obtained  by  giving  it  in  divided  doses  until  it  freely  moves  the  bowels. 

' '  To  promote  the  elimination  of  the  quadrurates  formed  in  the  kidneys 
and  so  to  prevent  their  absorption  into  the  blood  is  to  strike  at  the  primary 
evil  in  the  causation  of  gout.  To  promote  this,  diuresis  should  be  increased 
and  the  acidity  of  the  urine  diminished.  Citrate  of  potassium  is  a  good 
diuretic,  which  not  only  increases  the  solubility  of  the  quadrurates,  but 
also  diminishes  the  acidity  of  the  urine,  and  should  be  continued  until 
moderate  alkalinity  of  the  urine  is  produced."     (Luff.) 

Salicylate  of  sodium  and  the  salicylate  of  lithium  have  been  more  or 
less  extensively  employed  in  the  treatment  of  acute  gout,  but  they  are 
greatly  inferior  to  colchicum. 

These  remedies  find  their  most  useful  field  in  those  cases  in  which 
colchicum  is  not  well  borne  by  the  stomach.  They  have  the  power  of 
clearing  the  system  of  uric  acid,  but  they  do  not  reach  the  primary  cause 
of  the  disease,  which  lies  in  a  faulty  metabolism. 

Various  basic  organic  compounds,  such  as  piperazin,  lycetol,  and 
lysidin,  have  been  recently  introduced  as  specifics  for  gout  and  uric  acid 
gravel.  But  the  opinions  as  to  their  value  are  so  conflicting  that  they  can- 
not at  present  be  recommended. 

In  this  study  of  gouty  pericementitis  the  writer  has  endeavored  to 
present  the  subject  in  such  a  manner  that  the  student  may  get  a  somewhat 
broad  view  of  that  condition  of  the  general  system  known  as  ' '  uricaci- 
dsemia,"  and  its  manifestations  in  the  various  tissues  of  the  body  other 
than  those  which  surround  the  root  of  the  tooth,  with  the  hope  that  the 
presentation  will  assist  in  clearing  up  some  of  the  misconceptions  of  those 
who  oppose  the  theory  and  of  some  of  its  over-zealous  advocates  who 
have  claimed  too  much  for  it. 


CHAPTEE    XL. 

PHAGEDENIC   PERICEMENTITIS. 

Definition. — Phagedena  (from  the  Greek  (payeZv^  to  eat)  is  a  spreading 
and  destructive  ulceration,  often  of  an  obstinate  character,  which  rapidly 
destroys  or  disintegrates  the  soft  parts. 

Dr.  Black  first  introduced  the  use  of  the  term  '  ^  phagedenic  pericemen- 
titis" to  describe  a  peculiar  form  of  pyorrhoea  alveolaris  whose  most  char- 
acteristic symptom  was  a  progressive  ulceration  and  destruction  of  the 
pericementum  and  alveolar  process. 

Phagedenic  pericementitis  may  be  described  as  an  inflammation  of  the 
peridental  membrane  accompanied  with  a  progressive  ulceration  of  a 
phagedenic  or  spreading  ty^De,  showing  a  marked  inclination  to  extend  or 
progress  most  rapidly  in  a  direction  corresponding  to  the  long  axis  of  the 
tooth,  and  beginning  apparently  at  the  gingival  border  of  the  gum  in  a 
slight  gingivitis,  but  really  in  the  marginal  attachment  of  the  membrane. 
The  disease  causes  destruction  of  the  pericemental  membrane  and  of  the 
alveolar  process  immediately  overlying  the  inflamed  area,  but  in  the  early 
stages  leaves  the  gum  intact.  This  process  of  disintegration  is  accom- 
panied with  a  slight  reddening  and  congestion  of  the  overlying  gum,  the 
formation  of  deep  narrow  pockets,  the  deposition  in  some  cases  of  calcic 
material,  and  the  discharge  of  a  variable  quantity  of  pus  which  makes 
Its  appearance  on  pressure  being  applied  over  the  inflamed  area. 

The  disease  may  be  either  acute  or  chronic  in  its  manifestations. 

Phagedenic  pericementitis  is  entirely  distinct  from  hsematogenic  calcic 
pericementitis,  in  that  the  inflammation  is  not  dependent  upon  the  forma- 
tion of  uratic  deposits,  and  that  the  destructive  process  always  begins  at 
the  marginal  attachment  of  the  membrane  and  progresses  towards  the 
apex  of  the  root,  spreading  less  rapidly  in  lateral  directions,  and  destroy- 
ing the  xDcricementum  and  alveolar  tissue  simultaneously  by  a  process  of 
molecular  necrosis,  while  it  presents  clinic  features  which  indicate  it  to  be 
an  infectious  disease.  In  hsematogenic  calcic  pericementitis  the  inflamma- 
tory process  is  dependent  upon  the  formation  of  uratic  deposits  within  the 
peridental  membrane  ;  these  concretions  are  deposited  in  locations  remote 
from  the  marginal  border  of  the  membrane  ;  they  form  distinct  abscesses, 
which -are  confined  at  first  to  these  locations,  and  have  no  connection  with 
the  oral  cavity  until  the  abscess  ruptures  ;  neither  does  the  affection  show 
any  characteristics  of  an  infectious  disease.  In  other  respects  they  have 
many  features  in  common. 

Causes. — In  regard  to  the  nature  and  etiology  of  phagedenic  perice- 
mentitis very  little  is  positively  known.  Certain  general  and  local  con- 
ditions seem,  however,  to  have  a  bearing  upon  the  disease,  either  as  causa- 
tive or  resultant  factors.  It  is  true  that  some  of  these  conditions  seem  to 
act  as  predisposing  and  others  as  exciting  causes  of  the  affection.  They 
568 


PHAGEDENIC    PERICEMENTITIS.  569 

may  therefore  be  divided  into  predisposing  and  exciting  causes,  the  former 
being  largely  of  constitutional  origin,  the  latter  principally  local. 

Predisposing  Causes. — Certain  systemic  conditions,  by  a  seeming 
predilection,  find  expression  in  various  inflammatory  manifestations  in  the 
peridental  membrane,  some  of  which  are  constructive  in  their  character, 
others  destructive  ;  as,  for  instance,  certain  gouty  conditions  cause  through 
irritation  of  the  pericementum  and  stimulation  of  the  cementoblasts  the 
formation  of  new  cement-tissue  (hypercementosis),  or  in  scurvy,  which 
causes  through  intense  inflammation  of  the  pericementum  destruction  of 
this  membrane  and  exfoliation  of  the  teeth. 

Phagedenic  pericementitis  generally  arises  under  the  influence  of  cer- 
tain diseases  or  unfavorable  conditions  of  health, — conditions  which  are 
productive  of  general  debility  and  degenerations  of  special  tissues  like  the 
pericementum, — and  it  is  manifested  either  as  a  complication  or  as  a 
sequel  of  these  conditions  and  diseases.  Among  the  more  common  general 
conditions  and  diseases  which  are  sometimes  complicated  with  phagedenic 
pericementitis  or  are  followed  by  it  are  hereditary  tendencies,  anaemia, 
locomotor  ataxia,  diabetes  mellitus,  albuminuria,  osteitis  deformans,  scurvy, 
certain  nervous  diseases,  typhoid  fever,  tropical  fever,  certain  infectious 
diseases,  particularly  the  exanthematic  fevers,  influenza.,  smallpox,  syph- 
ilis, gonorrhoea,  and  tuberculosis,  pyaemia,  nephritis,  pregnancy,  sterility, 
and  the  selective  action  of  those  drugs  which  produce  mercurialism,  plum- 
bism,  iodism,  and  alcoholism. 

The  pericementitis  of  scurvy,  mercurialism,  plumbism,  and  iodism  in 
their  aggravated  forms  are  always  of  the  phagedenic  type. 

It  should  be  remembered,  however,  that  the  teeth  are  dermal  append- 
ages, and  are  therefore  more  liable  on  this  account  to  be  affected  by  such 
diseases  and  drug  impressions  as  are  peculiarly  manifested  in  or  have  a 
predilection  for  epiblastic  and  hypoblastic  tissues.  The  teeth  are  also  in 
a  certain  sense  transitory  organs,  and  are  therefore  prone  to  take  on  senile 
and  other  degenerative  changes,  resulting  in  atrophy  of  the  pericementum 
and  alveolar  structures  and  loss  of  the  teeth.  For  this  reason  some 
authorities  have  looked  upon  phagedenic  pericementitis  as  a  ^'premature 
senile  degeneration"  or  alveolar  atrophy.  The  disease  is  most  common 
between  thirty  and  fifty  years  of  age. 

It  is  interesting  to  notice  the  great  similarity  in  the  clinic  features  of 
phagedenic  pericementitis  and  of  the  oral  manifestations  of  osteitis  de- 
formans as  described  by  Sir  James  Paget.  He  says,  '^The  surrounding 
gum  becomes  spongy,  deep  red,  and  sometimes  tender ;  it  separates  from 
the  neck  of  the  tooth,  while  at  the  same  time  the  periosteum  (perice- 
mentum) suppurates  and  discharges  pus,  which  is  continually  oozing  out 
around  the  necks  of  the  teeth,  and  can  be  generally  pressed  out  in  great 
quantity.  It  is  extremely  chronic,  beginning  generally  in  early  middle 
age  and  may  continue  for  an  indefinite  time  without  influencing  the  gen- 
eral health.  The  early  stages  of  the  disease  are  sometimes  attended  with 
pain  varying  widely  in  severity.  The  breath  is  usually  foul,  the  roots  of 
the  teeth  covered  with  irregular  masses  of  greenish  or  blackish  tartar,  the 
discharges  offensive,  and  the  whole  mouth  tender." 


570  OPERATIVE    DENTISTRY. 

Certain  local  conditions;  like  traumatisms,  malocclusions,  loss  of  antag- 
onizing teetli,  unhygienic  conditions  of  the  mouth,  disease  of  the  teeth, 
marginal  gingivitis,  etc.,  act  as  local  predisposing  causes  of  the  disease. 

Exciting  Causes. — According  to  Black,  the  disease  may  have  ''its 
beginning  in  a  gingivitis  that  in  its  inception  cannot  be  distinguished  from 
the  simple  form,  or  its  character  may  be  marked  by  deposits  of  either 
salivary  or  seruraal  calculus." 

The  active  or  exciting  causes  of  the  disease,  in  the  opinion  of  the  writer, 
are  local  traumatisms  and  pyogenic  infections  which  induce  a  marginal 
gingivitis  5  this,  through,  the  continuity  of  structure,  is  transmitted  to  the 
already  debilitated  pericementum,  when  the  conditions  are  favorable, 
through  a  lowered  vital  resistance,  for  the  development  of  the  pus-pro- 
ducing micro-organisms. 

Traumatic  injuries  of  the  margins  of  the  gums,  caused  by  the  sharp  par- 
ticles of  very  hard  foods  or  the  lodgement  of  such  particles  beneath  the  free 
mai-gins  of  the  gums,  the  too  vigorous  use  of  the  toothbrush,  toothpicks,  and 
floss-silk,  or  the  accumulation  of  cervical  deposits,  are  frequent ;  such  wounds 
and  abrasions,  though  slight,  may  nevertheless  readily  establish,  infection 
by  giving  entrance  to  the  tissues  of  the  pyogenic  organisms  of  the  mouth. 
And  as  debilitated  tissues  are  prone  to  degenerative  changes,  inflammation 
and  ulceration  are  readily  produced.  Or  a  marginal  gingivitis  may  be 
established  through  a  catarrhal  condition  of  the  oral  mucous  membrane 
following  a  general  catarrhal  state  of  the  upper  air-passages,  induced  by 
coryza  or  influenza,  or  it  may  be  produced  by  unhygienic  conditions  of 
the  mouth,  the  result  of  improper  care,  or  by  thermic  irritation  of  the 
mucous  membrane,  induced  by  the  ingestion  of  excessively  hot  liquids 
and  foods. 

Pathology. — -An  examination  of  the  teeth  which  have  been  lost  by 
phagedenic  pericementitis  may  not  discover  any  abnormal  appearances, 
except  that  the  roots  are  denuded  of  every  vestige  of  the  XDcridental  mem- 
brane. They  may  have  deposits  upon  their  roots  or  they  may  be  entirely 
free  from  them.  The  teeth  are  usually  of  fine  organization  and  dense 
structure,  and  singularly  free  from  caries.  The  pulp-chamber  is  usually 
small,  and  the  pulp  shows  evidences  of  atrophy. 

An  examination  of  the  teeth  in  situ  reveals  the  fact  that  upon  one  side 
the  root  is  denuded  of  its  pericementum  to  a  considerable  depth,  while 
perhaps  upon  all  other  sides  it  is  intact.  This  denudation  of  the  peri- 
cementum is  most  often  upon  the  lingual  or  buccal  aspects  of  the  root  in 
the  order  named,  while  it  is  less  rarely  found  upon  the  mesial  and  distal 
surfaces.  The  alveolar  process  is  usually  destroyed  to  nearly  the  same 
depth  as  the  pericementum,  while  the  edge  is  denuded  and  rough  and 
apparently  the  seat  "of  caries,  if  one  may  judge  from  the  peculiar  odor  of 
the  pus  (characteristic  of  bone  caries)  which  exudes  from  about  the  mar- 
gins of  the  gums.  This  degenerative  process  sometimes  destroys  the 
pericementum  and  the  alveolar  septum  between  two  approximating  teeth, 
while  the  remaining  parts  are  unharmed  for  a  considerable  period  there- 
after. The  pockets  not  infrequently  extend  to  the  apex  and  involve  the 
apical  space,  even  permitting  an  instrument  to  pass  over  the  apex,  while 


PHAGEDENIC    PERICEMENTITIS,  571 

the  attacliment  of  the  membrane  to  the  balance  of  the  alveolus  will  remain 
in  a  comparatively  normal  condition  for  an  indefinite  period.  The  formation 
of  a  pocket  upon  one  side  of  the  root  usually  causes  the  tooth  to  move 
out  of  position,  the  displacement  occurring  in  a  direction  from  the  dis- 
eased surface.  (Black.)  Occasionally  the  entire  gingival  margin  of  the 
pericementum  is  attacked  and  the  whole  membrane  rapidly  destroyed, 
causing  extrusion  of  the  tooth  and  finally  exfoliation. 

The  examination  develops  the  further  fact  that  some  of  these  cases  have 
subgingival  deposits  upon  their  roots,  while  others  do  not.  The  formation 
of  the  deposits  in  these  cases  is  evidently  the  result  of  the  disease,  and 
the  calcic  material  is  in  all  probability  derived  from  the  salivary  secre- 
tions and  the  pus.  Gingivitis  is  the  rule  wherever  calcic  deposits  are 
found  upon  the  roots  of  the  teeth.  Black  thinks  in  these  cases  the  phage- 
denic pericementitis  is  complicated  with  ''calcic  inflammation,"  and  that 
''this  dual  condition  has  long  delayed  the  recognition  of  phagedenic  peri- 
cementitis as  an  independent  disease." 

In  those  cases  which  do  not  present  calcic  deposits  there  is  often  an 
absence  of  gingival  inflammation,  and  instead  there  is  an  atrophic  con- 
dition of  that  portion  of  the  gum-tissue  which  has  lost  the  support  of  the 
alveolar  process,  which  often  exposes  the  root  to  the  extent  of  the  lost 
alveolar  plate. 

The  gums,  as  a  rule,  give  little  or  no  evidence  by  their  appearance  of 
the  condition  of  the  pericementum  and  alveolar  plate  lying  beneath.  Oc- 
casionally, however,  the  ulcerative  process  which  has  attacked  the  peri- 
cementum will  be  communicated  to  the  gum  and  the  tissue  overlying  the 
pocket  rapidly  destroyed.  The  edges  of  the  notch  thus  formed  in  the 
gum-tissue  will  be  covered  with  very  red,  coarse  granulations,  which  bleed 
upon  the  least  provocation,  and  are  covered  in  the  morning  with  an  ichorous 
discharge.  After  the  ulcerative  process  reaches  the  limit  of  the  destroyed 
alveolar  plate  the  edges  of  the  gum  heal  and  form  a  close  union  with  the 
exposed  surface  of  the  root,  thus  obliterating  the  pocket,  and  in  many 
instances  controlling,  and  in  a  few  others  completely  arresting,  the  further 
progress  of  the  affection.  This,  the  writer  believes,  is  nature's  method 
of  curing  the  disease. 

Another  peculiar  feature  of  this  disease,  which  was  first  pointed  out  by 
Black,  is  a  thickening  and  eversion  of  the  alveolar  margins.  The  phe- 
nomenon is  peculiar  in  that  as  the  alveolar  plate  is  thinned  upon  the  sur- 
face lying  next  to  the  root  of  the  tooth  new  bony  material  is  laid  down 
upon  its  gingival  surface,  so  that  upon  examination  the  alveolar  edge  is 
found  to  be  not  only  thickened  but  has  the  appearance  of  being  everted. 

The  disease  is  irregular  in  its  attacks  ;  sometimes  it  will  be  confined  for 
a  considerable  period  to  the  side  of  the  root  of  a  single  tooth,  or  of  two  or 
more  teeth  upon  the  same  side  of  the  mouth  ;  at  others  it  may  attack  one 
or  more  teeth  upon  opposite  sides  of  the  mouth, — and  this  is  the  more  com- 
mon condition, — and  then  spread  to  adjoining  teeth  until  one  by  one  the 
entire  denture  may  be  lost.  This  latter  peculiarity  of  the  disease  has 
given  rise  to  the  oj)inion  among  some  authorities  that  it  was  infectious  in 
its  nature.     Neither  individual  teeth  nor  groups  of  teeth  seem  to  possess 


572  OPERATIVE    DENTISTRY. 

any  especial  liability  to  be  attacked  by  the  disease,  but  all  are  equally 
susceptible. 

Witze],  Black,  Arkovy,  Izlai,  Miller,  and  others  are  of  tbe  opinion 
that  the  disease  is  essentially  infectious,  and  that  it  has  its  origin  in  some 
specific  micro-organism  ;  but  none  of  these  investigators  has  as  yet  been 
able  to  isolate  the  specific  germ.  On  the  other  hand,  the  fact  that  the  dis- 
ease shows  a  marked  tendency  to  bilateral  symmetry,  and  the  teeth  fii-st 
attacked  are  often  not  those  which  are  most  liable  to  ptyalogenic  dei)osits, 
strengthens  the  theory  of  its  constitutional  origin. 

Symptoms  and  Diagnosis. — The  most  marked  and  characteristic 
symptoms  of  phagedenic  pericementitis  are  a  thickened  and  turgid  condi- 
tion of  the  margins  of  the  gums,  the  ulceration  and  destruction  of  the 
peridental  membrane  upon  one  or  more  sides  of  the  root,  forming  deep 
pockets,  which  may  reach  to  the  apex,  or  the  destruction  of  the  perice- 
mentum may  i)rogress  until  it  encircles  the  entire  root.  The  process  of 
ulceration  always  begins  at  the  cervical  margin,  and  progresses  most  rapidly 
in  a  direction  towards  the  apex.  Accomi^anying  the  ulcerative  process 
there  is  a  discharge  of  pus  and  a  molecular  disintegration  (caries)  of  the 
alveolar  process.  The  odor  of  the  pus  is  characteristic  of  caries  of  bone. 
The  edges  of  the  alveolar  process  are  denuded  and  rough,  and  the  disinte- 
gration of  this  tissue  keeps  pace  with  the  destruction  of  the  j)ericementum. 

Loosening  of  the  teeth  is  an  early  symptom,  the  degree  depending  upon 
the  character  of  the  inflammation  and  the  extent  of  pericemental  and 
alveolar  destruction. 

The  gum  in  the  early  stages  of  the  disease,  as  a  rule,  maintains  its  in- 
tegrity over  those  portions  of  the  root  which  have  lost  the  pericementum 
and  alveolar  plate,  but  in  the  more  advanced  stages  recession  takes  place, 
sometimes  by  atrophy,  at  others  by  ulceration. 

When  the  gum  is  being  destroyed  by  ulceration  the  margins  are  cov- 
ered with  coarse  granulations  of  an  indolent  character,  and  are  covered 
during  the  intervals  between  meals,  and  in  the  morning,  with  an  ichorous 
discharge.  The  discharge  of  pus  is  most  abundant  in  those  cases  in  which 
the  pockets  are  deep  and  the  gum  intact. 

An  atrophy  or  ulceration  of  the  gum  which  progresses  to  the  limit  of 
the  loss  of  the  pericementum  and  alveolar  plate  obliterates  the  pocket  and 
tends  to  an  abatement  of  the  symptoms  of  the  disease. 

As  a  rule,  little  or  no  pain  attends  the  progress  of  this  form  of  pyor- 
rhoea alveolaris. 

A  marked  symptom  of  the  disease  is  the  movement  or  displacement  of 
the  teeth,  which  begins  as  soon  as  a  pocket  is  formed  at  the  side  of  the 
root.  This  movement  takes  place  in  a  direction  oj)posite  to  the  surface 
upon  which  the  pocket  is  formed,  as,  for  instance,  in  a  superior  central 
incisor,  if  the  pocket  is  uj)on  the  lingual  surface,  the  tooth  moves  out- 
ward, if  upon  the  mesial  surface,  it  moves  distally,  etc.  In  other  cases 
the  tooth  will  turn  u^^on  its  axis,  usually  in  an  outward  direction,  causing 
the  mesio-labial  angle  to  become  most  prominent  when  the  pocket  is  upon 
the  mesial  surface,  etc. 

Deposits  are  rarely  found  upon  the  roots  of  the  teeth  in  the  early  stages 


Fig.  638. — Fibroid  degeneration  of  the  pulp  from  a  case  of  pyorrhoea  alveolaris.    (V.  A.  Latham.)    X  110. 


Fig.  639.— Human  pulp  m  si<M  showing  calcic  degeneration.     (V.A.Latham.)     >C  65.    Thrombus  in 
vessels  at  A  and  calciflc  areas  at  B. 


Blood-vessel 


Blood-vessel 


Fig.  640. — Hyaline  degeneration  of  the  pulp.     (V.  A.  Latham.)     X  100. 


^Pt^;*?^ 

M 

^    i 

/^ 

f        • 

^    .^ 

''  ^1 

'f        i 

Wtw^^ 

^'"fyif 

j^l 

Pi 

^ 

M 

^L  .    I 

^' 

V?  jt>  J^^l 

Fig.  641. — Ctolloid  degeneration  of  the  pulp.     (V.  A.  Latham.)     X  21.2.5. 


PHAGEDENIC    PERICEMENTITIS.  573 

of  the  disease,  except  at  the  cervices,  but  in  the  later  stages  of  the  chronic 
form  the  presence  of  dark-green  deposits  is  the  rule.  In  fact,  the  presence 
of  deposits  marks  the  chronic  form  of  the  disease.  In  the  acute  form  de- 
posits are  rarely  or  never  formed  upon  the  roots. 

These  facts  seem  to  prove  very  conclusively  that  calcic  deposits  are  not 
the  cause  of  this  form  of  the  disease,  but  are  rather  a  consequence  of  it, 
being  formed  from  the  salivary  secretions  and  the  pus. 

Death  of  the  pulj)  sometimes  occurs  as  a  result  of  the  involvement  of 
the  apical  tissues  in  the  process  of  pericemental  ulceration,  or  it  may 
occur  as  a  result  of  degenerative  changes.  These  degenerations  may  be 
fibroid  in  character,  as  shown  in  Fig.  638,  or  calcic,  as  seen  in  Fig.  639,  or 
hyaline,  as  represented  in  Fig.  640,  or  colloid,  as  shown  in  Fig.  641.  Under 
such  circumstances  the  disease  may  be  complicated  with  an  alveolar  ab- 
scess. In  multiple-rooted  teeth  one  root  may  be  so  affected  while  the  pulp 
in  the  others  may  still  be  vital. 

As  the  disease  progresses  the  teeth  become  more  and  more  loose,  until 
finally  they  are  picked  out  with  the  fingers  or  they  drop  out. 

Differential  Diagnosis. — There  are  two  disorders  affecting  the  peri- 
cementum and  the  alveolus  which  under  certain  circumstances  might  be 
mistaken  for  this  disease, — viz.,  gouty  pericementitis  and  alveolar  abscess 
discharging  at  the  cervical  margin  of  the  gum.  The  former  may  be  differ- 
entiated by  the  absence  usually  of  cervical  deposits  except  in  the  later 
stages  of  the  disease,  nearly  normal  attachment  of  the  gingival  margins, 
hsematogenic  deposits  found  high  up  in  the  pockets  towards  the  apex 
of  the  root,  the  history  of  a  painful  swelling  (abscess)  upon  the  gum,  and 
periodic  soreness  of  the  tooth.  This  may  be  supplemented  by  the  family 
and  personal  history  which  give  evidences  of  other  gouty  conditions. 

The  latter  may  be  differentiated  by  applying  those  tests  to  determine 
the  vitality  of  the  teeth  which  have  been  mentioned  in  the  chapter  on 
^'Pulpless  Teeth." 

Prognosis. — Very  little  encouragement  can  be  given  as  to  the  perma- 
nent conservation  of  those  teeth  which  have  been  once  attacked  by  this  dis- 
ease ;  and  yet  by  a  judicious  system  of  general  and  local  treatment,  which 
shall  build  up  the  debilitated  condition  of  the  body,  and  if  possible  re- 
establish normal  function  in  the  various  excretory  organs  and  place  the 
teeth  and  the  mouth  in  the  best  possible  hygienic  condition,  much  may  be 
hoped  for  in  the  way  of  controlling  the  progress  of  the  disease. 

But  the  common  history  of  such  cases  reveals  the  fact  that  sooner  or 
later  the  teeth  are  lost.  When  the  disease  assumes  an  acute  type  the 
affected  teeth  may  be  lost  in  a  few  months  ;  when  the  chronic  form  prevails 
the  ultimate  loss  of  the  teeth  may  compass  many  years. 

Treatment. — Treatment  will  prove  of  little  benefit  if  it  is  applied  to 
the  correction  of  the  local  symptoms  only  ;  for  inasmuch  as  the  disease  is 
influenced  by  or  is  largely  due  to  certain  abnormal  states  of  the  general 
sj^stem,  it  stands  to  reason  that  these  abnormal  conditions  must  be  cor- 
rected if  local  treatment  is  to  be  of  any  real  value. 

It  is  best,  therefore,  at  the  beginning  to  call  for  a  consultation  with  the 
family  medical  adviser  and  go  over  the  case  together,  and  then  decide* 


574  OPERATIVE    DENTISTRY. 

upon  the  line  of  general  treatment  which  the  particular  case  requires, 
leaving  the  conduct  of  this  part  of  the  case  in  the  hands  of  the  physician, 
while  the  dentist  addresses  himself  to  the  local  treatment  of  the  oral  mani- 
festations. By  such  co-operation  between  the  general  practitioner  and  the 
oral  specialist  a  much  better  service  can  be  rendered  the  patient  than  if 
each  wrought  upon  the  case  independently  and  with  no  harmony  of  action. 

The  local  conditions  which  demand  correction  are  malocclusion,  extru- 
sion or  rotation  of  the  tooth,  loss  of  antagonizing  teeth,  undue  mobility, 
the  presence  of  suppurative  discharges  and  carious  alveolar  structure, 
foreign  deposits,  inflammation  of  the  gums,  and  general  unhygienic  con- 
ditions of  the  mouth. 

Malocclusions  are,  without  doubt,  responsible  for  the  establishment  of 
the  disease  in  many  instances  by  exciting  congestion  and  other  inflamma- 
tory symptoms  in  the  peridental  membrane.  The  correction  of  the  mal- 
occlusion by  simply  grinding  off  the  opposing  tooth  or  dressing  down  a 
filling  will  often  give  immediate  relief  and  arrest  the  further  progress  of 
the  disease  for  a  considerable  period. 

Extrusion  and  rotation  of  the  teeth  upon  their  axes  is  often  arrested  in 
the  same  manner,  for  many  such  cases  have  their  origin  in  a  malocclusion. 
Certain  cases,  however,  seem  to  be  dependent  upon  the  inflammatory  dis- 
turbances of  the  peridental  membrane,  the  malposition  increasing  with 
the  increasing  destruction  of  the  pericementum. 

Drs.  M.  L.  Ehein  and  D.  D.  Smith  have  both  recommended  as  a  remedy 
for  the  correction  of  the  abnormal  conditions  which  iiroduce  this  shifting  of 
the  teeth  the  devitalization  of  the  pulp.  It  is  argued  that  by  devitalizing 
the  pulp  the  supply  of  blood  which  was  originally  intended  for  the  pulp  is 
directed  to  the  peridental  membrane,  and  the  threatened  degeneration  of 
this  structure  thereby  averted.  The  argument  seems  good,  and  clinic  ex- 
perience tends  to  substantiate  the  argument,  although  there  have  not  been, 
to  the  knowledge  of  the  writer,  any  corroborated  histologic  data  presented 
in  proof. 

Loss  of  antagonizing  teeth  is  a  most  prolific  source  of  extrusion  of  the 
bicuspids  and  molars.  The  loss  of  a  tooth  from  any  cause  throws  its 
opposing  fellow  into  disuse,  and  thereby  predisposes  it  to  certain  diseases 
of  the  pericementum  like  atrophy  and  degeneration.  The  substitution  of 
the  lost  teeth  by  a  bridge  or  a  plate  often  corrects  these  tendencies  if  taken 
in  time. 

Undue  mobility  should  be  corrected  by  ligaturing,  wiring,  or  splinting, 
after  the  manner  already  described.  Excessive  mobility  of  the  tooth  in- 
creases the  irritation  of  the  peridental  membrane,  and  by  that  much  aggra- 
vates the  already  existing  morbid  condition. 

Local  treatment  directed  to  the  removal  of  deposits  and  necrotic  tissue, 
and  the  sterilization  of  the  pockets,  will  be  of  greater  benefit  if  the  teeth 
can  be  held  firmly  in  place — put  at  rest— during  the  healing  process. 

The  treatment  of  the  pockets  is  an  important  feature  in  these  cases. 
Various  opinions  are  held  upon  this  part  of  the  subject.    Black  *  is  cautious 

*  American  System  of  Dentistry,  vol.  i.  p.  981. 


PHAGEDENIC    PERICEMENTITIS.  575 

not  to  injure  the  gnui  margin  in  the  removal  of  the  deposits,  but  when 
once  beyond  the  gum  margin  to  use  vigorous  means  to  remove  the  concre- 
tions, not  fearing  to  injure  the  tissues  which  line  the  pocket.  Burchard* 
also  offers  the  same  suggestion.  The  writer  has  found  an  opposite  course 
of  treatment  in  reference  to  the  gum  margins  to  give  the  best  results.  This 
plan  of  treatment  was  suggested  more  than  twenty  years  ago  by  studying 
certain  cases  in  which,  by  atrophy  or  ulceration  of  the  gum  overlying  the 
root  of  a  tooth,  the  pocket  had  been  obliterated  and  a  spontaneous  cure 
established.  This  evidently  was  nature's  method  of  arresting  the  progress 
of  the  disease,  and  therefore  it  seemed  safe  to  follow  her  leadings.  From 
that  time  to  this  the  writer  has  employed  it  many  times,  often  with 
the  very  best  results,  and  has  to-day  cases  under  observation  which  were 
treated  by  this  method  fifteen  to  eighteen  years  ago,  and  are  still  doing 
good  service.  Not  all  cases,  not  even  a  majority  so  treated,  however, 
prove  successful ;  but  where  the  general  condition  of  the  system  can  be 
built  up  to  normal  tone,  and  the  patient  will  keep  the  mouth  in  a  hygienic 
condition,  the  best  results  follow. 

The  method  is  to  excise  the  gum  down  to  the  bottom  of  the  pocket 
by  removing  a  V-shaped  flap,  the  apex  of  the  flap  pointing  towards  the 
apex  of  the  root.  This  exposes  the  denuded  surface  of  the  root  and  the 
carious  edge  of  the  alveolus,  and  makes  it  possible  after  the  hemorrhage 
has  ceased  to  find  all  of  the  concretions,  remove  the  ulcerating  pericemen- 
tum, and  curette  the  carious  alveolar  margins.  It  also  secures  perfect 
drainage  and  makes  sterilization  easy. 

Objection  has  been  raised  to  its  employment  upon  the  labial  aspect  of 
the  anterior  teeth,  and  for  cosmetic  reasons  the  objection  is  valid.  An 
exposed  root,  with  a  healthy  pericementum,  alveolus,  and  gum  surrounding 
it,  is,  however,  a  thousand  times  better  than  leaving  the  gum  intact  and 
with  it  all  the  disgusting  features  of  the  disease. 

The  first  cases  treated  by  this  method  were  superior  incisors  having 
pockets  upon  the  lingual  aspect  of  the  root.  Some  of  these  did  so  well 
that  it  was  tried  upon  the  palatal  roots  of  molars,  and,  as  courage  was 
gained,  to  all  of  the  teeth  in  any  location  of  the  mouth.  The  method  suc- 
ceeds best  if  done  in  the  early  stage  of  the  disease,  but  it  proves  beneficial 
in  all  stages.  The  only  serious  objection  to  the  operation  being  performed 
upon  the  labial  surfaces  of  the  roots  of  the  anterior  teeth  is  the  one  already 
mentioned,  and  for  that  reason,  if  the  patient  has  a  short  lip  and  shows  the 
gums  in  talking  and  laughing,  it  would  prove  an  ugly  disfigurement ;  aside 
from  this  the  operation  may  be  commended.  In  such  cases  as  last  described 
the  gum  may  be  slit  open  from  the  margin  towards  the  apex,  the  flaps  laid 
back  to  expose  the  carious  margin  of  the  alveolus,  as  suggested  by  Garret- 
son,  and  the  gum  afterwards  brought  together  and  closed  by  sutures. 

The  instruments  which  aie  best  adapted  for  curetting  the  alveolar 
border  in  this  operation  are  hoe  or  spoon- bladed  excavators  with  an  angle 
of  about  forty-five  degrees,  or  sharp  chisels.  During  the  operation  the 
side  of  the  blade  should  be  kej^t  close  to  the  root  in  order  that  the  gum- 

*  Dental  Pathology,  Therapeutics,  and  Pharmacology,  p.  475. 


576  OPERATIVE    DENTISTRY. 

tissue  may  not  be  unnecessarily  injured.  The  same  instruments  are  valu- 
able for  curetting  the  alveolus  in  any  form  of  operation  that  may  be 
adopted. 

The  late  Dr.  Allport  designed  a  bur  (Fig.  642)  for  the  especial  purpose 
of  curetting  the  alveolar  border  by  passing  the  instrument  into  the  pocket 
from  the  margin  of  the  gum.     This  instrument  permits  the 
'*^"  '  "■       removal  of  the  diseased  border  without  unnecessarily  injuring 
*      either  the  cementum  or  the  overlying  gum.     The  tapering  en- 
largement of  the  instrument  between  the  bur  and  the  shank 
allows  the  head  of  the  instrument  to  be  kept  close  to  the  ce- 
mentum without  cutting  its  surface,  and  insures  the  certainty 
of  a  complete  removal  of  all  the  carious  portions  of  the  alveolus. 
Effort  should  be  made  also  to  freshen  the  margin  of  the 
pericementum  by  passing  a  delicate  hoe-shaped  instrument  of 
the  pattern  just  described  to  the  bottom  of  the  pocket  and 
sweeping  around  the  denuded  edge  of  the  alveolar  plate.     The 
Dr.  Aiiport's     p^g^  blood,  and  the  debris  of  the  operation  can  be  cleared  out 
of  the  pocket  by  irrigating  it  with  hydrogen  dioxide,  and  then 
sterilizing  with  a  1  to  500  solution  of  mercuric  chloride  in  water,  or  the 
same  strength  solution  may  be  made  in  hydrogen  dioxide.     The  Dunn 
medicinal  syringe  is  a  most  convenient  instrument  for  the  purpose  of  irri- 
gating such  pockets  and  of  applying  other  liquid  remedies. 

Caustic  and  escharotic  i-emedies  should  be  avoided  after  such  an  opera- 
tion, as  in  a  majority  of  cases  the  application  of  such  powerful  agents 
would  prevent  the  process  of  granulation  by  paving  the  way  for  the  pro- 
duction of  more  necrotic  tissue  in  the  very  location  in  which  a  moment 
before  so  much  pains  had  been  taken  to  remove  it.  Such  kind  of  treat- 
ment in  general  surgery  would  only  be  considered  permissible  in  cases  of 
malignant  disease  where  the  surgeon  felt  that  there  was  quite  strong  pre- 
sumptive evidence  that  all  of  the  malignant  tissue  had  not  been  removed. 
But  if  applied  under  any  other  circumstances  he  would  expect  to  find  his 
efforts  to  produce  healing  of  the  wound  defeated  by  the  presence  of  necrotic 
tissue,  which  must  be  again  removed  before  regeneration  could  take  place. 
Black  recommended  making  a  semicircular  incision  in  the  gum  over 
the  carious  alveolar  border,  raising  the  flap  and  operating  through  this 
opening  with  sharj)  chisels,  and,  after  irrigation  with  hydrogen  dioxide, 
stitching  the  flap  in  position.  The  main  object  of  this  operation  is  to 
remove  the  carious  material  without  injuring  the  gum  margin. 

The  after-treatment  should  consist  of  thorough  hygienic  care  of  the 
mouth  and  the  use  of  antiseptic  stimulating  and  astringent  mouth  lotions. 
Tincture  of  capsicum  and  myrrh,  one  part  capsicum  to  four  parts  of 
myrrh  (one  teaspoonful  to  a  goblet  of  water),  is  one  of  the  best  stimu- 
lating and  astringent  lotions  for  this  purpose. 

Replanting. — Treatment  of  this  disease  by  extraction  and  replanting 
has  been  recommended  from  time  to  time,  but  the  operation  has  met  with 
such  indifferent  success  that  it  has  never  become  a  popular  method  of 
treatment.  The  writer  some  ten  years  ago  made  several  of  these  opera- 
tions in  dispensary  and  private  practice,  and  although  at  first  they  gave 


PHAGEDENIC   PERICEMENTITIS.  577 

great  promise  of  a  successful  issue,  all  of  them  wei-e  lost  inside  of  two 
years  as  the  result  of  the  recurrence  of  the  disease  in  an  acute  form  follow- 
ing slight  injuries.  The  methods  adopted  were  the  same  as  those  described 
in  the  chapter  on  dento-alveolar  abscess. 

Sponge-Grafting.— Dr.  E.  C.  Briggs  *  and  the  late  Dr.  W.  H.  Atkin- 
son t  first  called  attention  to  the  use  of  sponge-grafts  to  reproduce  tissue 
lost  by  this  disease,  and  while  successes  were  undoubtedly  obtained  under 
favorable  conditions  of  oral  hygiene,  the  great  majority  of  such  operations 
in  the  mouth  were  failures,  because  of  the  difficulty  in  obtaining  and 
maintaining  aseptic  conditions. 

Electricity. — The  employment  of  electricity  in  its  various  forms  is 
sometimes  beneficial  in  the  treatment  of  those  cases  of  the  disease  which 

Fig.  643. 


Improved  dento-electric  cautery. 

are  free  from  deposits.  The  writer  has  found  the  best  results  to  follow  the 
application  of  the  galvanic  cautery  to  the  diseased  tissues  of  the  pockets, 
and  afterwards  applying  a  mild  faradic  current  to  stimulate  the  circu- 
lation of  the  pericemental  membrane. 

Before  applying  the  cautery  a  ten  per  cent,  solution  of  cocaine  should 
be  ajjplied  to  the  pocket.  Eucaine  or  chloretone  in  proper  strength  will 
answer  an  equally  useful  purpose,  and  be  less  liable  to  produce  unfavorable 
constitutional  impressions.  After  the  gum  has  become  anaesthetized  the 
cautery-point  (Fig.  643)  may  be  applied  and  the  current  turned  on  for  a 
sufficient  space  of  time  to  permit  the  cauterizing  of  the  margin  of  the  peri- 
cementum, the  whole  surface  of  the  pocket,  and  the  carious  border  of  the 
alveolus.  The  parts  should  next  be  irrigated,  and  instruction  given  to 
the  patient  to  keep  the  mouth  thoroughly  clean  by  the  use  of  antiseptic 
lotions,  etc.  The  cauterized  tissue  sloughs  away  in  a  day  or  two  and 
healthy  granulations  appear  upon  its  surface.  The  faradic  current  may 
now  be  employed  to  stimulate  the  sluggish  circulation  of  the  j)ericemental 
membrane  by  applying  the  anode  to  the  gum  over  the  affected  root  and 
the  cathode  to  the  external  surface  beneath  the  jaw. 

The  current  employed  should  never  be  strong  enough  to  be  unpleasant. 
The  duration  of  the  treatment  may  be  from  ten  to  twenty  minutes.  Catapho- 
resis  may  also  be  employed  with  cocaine  to  produce  local  anaesthesia,  and 
also  to  obtain  diffusion  of  such  drugs  as  are  employed  to  stimulate  the  dis- 
eased tissues  to  a  more  healthy  functional  activity. 

*  Transactions  American  Medical  Association,  1884. 

t  Transactions  American  Dental  Association,  1885,  pp.  152-154. 

37 


CHAPTER    XLI. 

ANESTHETICS,    LOCAL   AND   GENERAL. 

Definition. — Anaesthetic  (Greek,  av,  priv.,  and  ai(Tdavtaeat^  to  feel),  a 
substance  that  produces  insensibility  to  feeling  or  to  acute  pain,  diminished 
muscular  action,  and  other  phenomena. 

Ancesthesia  is  a  state  or  condition  of  insensibility  or  loss  of  feeling  due 
to  pathologic  conditions  of  the  nerve-centres,  of  the  nerve-trunks,  or  of 
their  peripheral  terminations,  or  to  the  artificial  production  of  insensi- 
bility by  means  of  the  toxic  effect  of  certain  substances  which  temporarily 
inhibit  the  sensory  functions  of  the  nerve-centres,  of  the  conducting  paths 

Fig.  644. 


Spray  apparatus — hand-instrument. 


of  the  nerves,  or  of  their  peripheral  terminations.  The  former  is  termed 
pathologic  ancesthesia,  the  latter  surgical  ancesthesia.  Surgical  ansesthetics 
are  of  two  general  classes, — viz.,  those  which  act  locally  at  the  point  of 
application  and  are  termed  local  ancesthetics,  and  those  which  act  through 
the  general  system,  termed  general  anoisthetics. 

Local  Ansesthetics. — Various  remedies  have  been  introduced  from 

time  to  time  for  the  purpose  of  producing  local  insensibility  to  pain, 

especially  for  the  extraction  of  teeth  and  other  minor  surgical  operations. 

Most  of  these,  however,  have  been  discarded  for  various  reasons,  such  as 

578 


ANESTHETICS,  LOCAL    AND    GENERAL. 


579 


the  unreliability  of  their  anaesthetic  power,  their  danger  of  producing 
general  toxic  effects  upon  the  central  nervous  system,  or  their  tendency  to 
cause  local  gangrene  and  sloughing  of  the  soft  tissues. 

These  remedies  may  be  divided  into  two  groups,— first,  those  which 
produce  ancesthesia  by  the  local  abstraction  of  heat;  and  second,  those  tvhich 
prodiice  ancesthesia  through  their  local  narcotic  effect  upon  the  tissues  to  which 
they  are  applied. 

ANESTHESIA   BY   THE   LOCAL   ABSTRACTION   OF   HEAT. 

Richardson  Method.— Dr.  B.  W.  Eichardson  (1866)  suggested  the 
use  of  ether  in  a  finely  divided  spray  thrown  upon  the  parts  to  be  oper- 

FiG.  (545.. 


Spray  apparatus — foot-instrument. 

ated  upon.     This  was  accomplished  by  means  of  a  hand  or  foot  bellows- 
atomizer.     Fig.  644  shows  the  hand- instrument :  Fig.  645  shows  the  foot- 


580  OPERATIVE    DENTISTRY. 

instrument.  The  strongest  ether  is  used,  freed  from  alcohol  and  water, 
and  mixed  more  or  less  with  atmospheric  air.  The  apparatus  consists  of 
a  bottle  to  contain  the  ether,  in  the  mouth  of  which  a  cork  is  fitted  and 
perforated  with  two  holes,  through  which  a  double  glass  tube  is  passed, 
one  extremity  of  the  inner  part  going  to  the  bottom  of  the  bottle  ;  above 
the  cork  a  tube  connected  with  the  bellows  pierces  the  outer  part  of  the 
double  tube  and  communicates  by  a  small  opening  with  the  interior  of  the 
bottle  at  the  inner  side  of  the  cork.  The  inner  tube,  reaching  to  the  bottom 
of  the  bottle,  delivers  the  ether  at  the  extremity  of  the  outer  tube. 
Compression  of  the  bellows  produces  two  currents  of  air,  one  of  which 
descends  and  presses  upon  the  surface  of  the  ether  contained  in  the  bottle, 
causing  it  to  rise  in  the  inner  tube  ;  the  other  ascends  through  the  outer 
tube  and  jjlays  upon  the  column  of  ether  as  it  ascends  through  the  inner 
tube,  converting  the  ether  into  a  finely  divided  spray. 

The  effect  of  the  spray  is  to  increase  the  rapidity  of  the  evaporation, 
which  j)roduces  intense  cold,  abstracting  the  heat  of  the  tissues  to  such  an 
extent  as  nearly  to  freeze  them,  and  thus  rendering  them,  for  the  time 
being,  insensible  to  pain. 

Ehiffolene,  which  is  a  distillation  product  of  petroleum,  is  used  for  the 
same  purpose  and  by  the  same  means.  This  substance  is  the  lightest  of 
all  known  liquids ;  its  specific  gravity  is  0. 625,  and  it  boils  at  70°  F.  It 
volatilizes  more  rapidly  than  ether,  and  consequently  reduces  the  tempera- 
ture of  the  tissues  much  more  rapidly  than  does  the  ether. 

Special  points  for  the  atomizer  have  been  devised  for  the  use  of  the 
dentist,  as  shown  in  Fig.  645,  which  permit  a  spray  to  be  thrown  upon 
each  side  of  the  gum. 

Letamendi's  Method. — Dr.  Letamendi  (1875)  suggested  an  improve- 
ment upon  Eichardson's  method  as  follows :  After  applying  a  perfectly 
neutral  sulphuric  ether  spray  for  about  two  minutes,  he  found  the  surface 
of  the  skin  becomes  red  or  hypersemic  and  is  the  seat  of  a  disagreeable 
sensation  of  cold,  but  no  sensation  of  burning  in  the  part.  At  this  stage 
of  the  process  he  made  a  slight  incision  in  the  centre  of  the  hypersemic 
area  with  a  convex-edged  bistoury,  eight  to  ten  millimetres  in  length,  but 
not  going  deeper  than  the  capillary  layer  of  the  cutis.  Almost  immedi- 
ately there  is  produced  an  anaemic  zone  around  the  incision  which  enlarges 
outwardly.  If  the  spray  is  again  made  to  play  for  a  few  seconds  over  the 
surface  which  has  become  anaemic,  the  region  becomes  perfectly  bloodless 
and  completely  anaesthetic.  The  advantage  of  this  method  is  that  the 
tissues  become  anEESthetic  much  sooner  than  by  the  Richardson  method, 
and  there  is  not  the  danger  of  so  reducing  the  temperature  as  to  freeze  the 
part  and  thus  cause  death  of  the  tissue  and  sloughing. 

Dr.  Letamendi  offers  the  following  theory  to  account  for  the  effect  of 
the  slight  incision  made  in  the  superficial  structures  of  the  skin.*  ''The 
abstraction  of  heat  caused  by  the  application  of  the  ether  spray  causes 
relaxation  and  consequently  dilatation  of  the  vessels.  The  incision  pro- 
duces a  sudden  reaction,  or  stimulus,  which  converts  the  extreme  dilatation 

*  Archives  de  Physiologie,  1875. 


ANESTHETICS,  LOCAL,    AND   GENERAL.  581 

into  an  extreme  contraction,  which  makes  the  anaemia  and  consequently 
the  anaesthesia  complete." 

Arnott  suggested  as  a  substitute  for  ether  and  rhigolene  a  freezing  mix- 
ture composed  of  ice  or  snow  and  common  table  salt  in  the  proportion  of 
two  parts  of  ice  or  snow  to  one  of  salt.  To  be  most  effective  it  should  be 
enclosed  in  a  bag,  one  side  of  which  should  be  made  of  rubber  sheeting 
and  the  other  of  a  coarse  meshed  linen  or  cotton  cloth,  to  permit  the  water 
formed  by  the  melting  of  the  ice  to  drain  away. 

In  applying  the  bag  to  produce  anaesthesia  of  the  gums  preparatory  to 
extracting  a  tooth,  the  cloth  side  should  be  placed  in  contact  with  the 
gums  and  tooth,  the  rubber  side  being  against  the  cheek,  thus  protecting 
it  from  injury  which  might  result  from  a  reduction  of  the  temperature. 
The  briny  fluid  which  accumulates  in  the  mouth  from  the  melting  of  the 
ice  may  be  removed  by  the  use  of  the  saliva  ejector. 

These  agents  have  given  place  during  the  last  few  years  to  the  use  of 
ethyl  chloride,  or  mixed  ethyl  and  methyl  chloride.     Ethyl  chloride  is  con- 
tained in  glass  tubes  with  capil- 
lary points  and  is  exceedingly  ^ig.  646. 

by  the  whiteness  of  the  tissue, 

when  it  will  be  found  to  be  in  a  state  of  analgesia  or  anaesthesia. 

Ethyl  chloride  is  inflammable  and  explosive,  and  must  therefore  be 
kept  in  a  cool  place  and  far  from  a  flame. 

The  danger  from  these  methods  lies  in  the  fact  that  if  great  care  is  not 
exercised  in  applying  the  spray,  the  vitality  of  the  tissues  may  be  destroyed 
by  reducing  the  temperature  to  a  lower  degree  than  living  tissues  can 
endure. 

It  is  interesting  to  note  in  this  connection  the  high  and  low  degrees  of 
temperature  that  are  safelj^  tolerated  by  vital  tissues.  If  the  temperature 
be  raised  above  130°  F.  or  140°  F.,  and  maintained  for  any  considerable 
period,  death  of  the  tissue  is  the  inevitable  result.  Higher  temperatures 
act  still  more  rapidly.  If  the  temperature  be  lowered  to  60°  F.  or  65°  F., 
and  maintained  for  any  considerable  time,  the  vitality  of  the  tissue  will  be 
destroyed.  (Ziegler.)  Much  higher  and  lower  degrees  of  temperature  can 
be  safely  borne  by  the  tissues  if  they  remain  at  these  temperatures  but 
for  a  short  time.  The  prolonged  application  of  the  hot- water  bag  or  of  the 
ice-bag  frequently  causes  death  of  limited  areas  of  soft  tissue,  which  slough 
and  are  sometimes  slow  to  heal. 

ANESTHESIA    BY   THE   LOCAL   NARCOTIC   EFFECT   OF   DRUGS. 

Cocaine. — "Cocaine  is  the  chief  alkaloid  extract  of  erythroxylon  coca, 
and  when  applied  locally  it  is  a  powerful  anaesthetic  in  a  limited  area. 
It  resembles  caffeine  in  its  action  on  the  nerve-centres,  and  atropine  in  its 
effects  upon  the  respiratory  and  circulating  organs.      Its  action  is  most 


582  OPERATIVE    DENTISTRY. 

rapid  upon  mucous  tissues.  Applied  to  the  conjunctiva,  it  dilates  the 
pupil  and  paralyzes  the  function  of  accommodation, ' ' 

The  introduction  of  cocaine  hydrochlorate  as  a  local  anaesthetic  has  to  a  very 
large  extent  superseded  all  substances  previously  employed  for  this  purpose. 

When  cocaine  was  first  used  for  the  purpose  of  i)roducing-  anaesthesia 
for  tooth  extraction,  it  was  applied  to  the  surface  of  the  gum,  but  its  anaes- 
thetic effect  did  not  extend  beyond  the  mucous  membrane,  consequently  it 
proved  of  little  value,  as  it  did  not  render  the  operation  painless.  Later 
it  was  employed  hypodermatically  in  solution,  when  the  tissues  so  infiltrated 
were  found  to  be  rendered  completely  anaesthetic. 

Immediately  following  its  employment  by  hypodermatic  injection,  many 
cases  were  reported  of  the  development  of  unpleasant  and  serious  consti- 
tutional symptoms,  and  not  a  few  fatal  cases  have  been  recorded  as  the 
result  of  paralysis  of  the  respiratory  and  cardiac  functions. 

These  serious  symptoms  and  fatal  results  demonstrated  the  fact  that 
cocaine  was  one  of  the  actively  poisonous  vegetable  alkaloids,  and  that  its 
use  must  be  restricted  to  such  persons  as  were  free  from  pulmonary  and 
cardiac  diseases,  and  that  the  dosage  needed  to  be  greatly  reduced  when 
applied  hypodermatically. 

It  had  been  customary  at  this  time  to  prescribe  cocaine  per  stomach  in 
doses  of  from  half  a  grain  to  one  grain,  and  hypodermatically  from  one- 
fourth  to  one-half  a  grain.  The  doses  now  administered  by  the  stomach 
are  from  one-fourth  to  three-fourths  of  a  grain,  and  hypodermatically  from 
one-twelfth  to  one-eighth  of  a  grain.  The  larger-sized  dose  cannot  be  ex- 
ceeded with  safety  to  the  patient. 

The  poisonous  effects  of  cocaine  are  manifested  upon  the  respiratory 
and  cardiac  centres,  and  when  long  continued,  as  in  the  ^'cocaine  habit," 
it  produces  insomnia,  moral  and  intellectual  decay,  emaciation,  and  death. 

Its  action  is  at  first  stimulating,  and  afterwards  narcotic  and  depressing. 
When  administered  in  a  fatal  dose  it  acts  by  paralyzing  the  respiratory 
and  cardiac  functions.  The  physiologic  antidote  is  morphine.  To  neu- 
tralize the  toxic  effect  of  cocaine  upon  the  respiratory  centres,  it  is  not 
necessary  to  administer  a  full  dose  of  morphine  ;  one-twelfth  of  a  grain  is 
suf&cient  for  the  purpose. 

To  neutralize  the  toxic  effect  upon  the  heart  and  arteries,  which  is  mani- 
fest in  the  form  of  tonic  spasms  of  the  muscles  of  these  organs,  one  drop 
of  a  one  per  cent,  solution  of  trinitrin  may  be  added  to  each  dose  adminis- 
tered hypodermatically. 

Curtis*  regards  volasem — an  extract  of  violets — as  the  ''natural  anti- 
dote" of  cocaine.  He  claims  for  the  drug  that  it  neutralizes  the  general 
toxic  effect  of  the  cocaine  while  it  does  not  interfere  with  its  local  effect. 
It  acts  by  stimulating  the  heart  action  and  the  respiratory  movements, 
contracts  the  arterioles,  and  raises  the  blood  pressure.  Administered  in 
five-drop  doses  immediately  before  the  cocaine  injection,  it  is  claimed  to 
effectually  prevent  the  general  toxic  effects  of  this  drug,  and  in  cocaine 
poisoning  is  an  efiScient  antidote. 

*  International  Dental  Journal,  1900,  p.  613. 


AN-JESTHETICS,  LOCAL    AND    GENERAL.  583 

Experience  in  the  use  of  cocaine  administered  hypodermatically  for  the 
extraction  of  teeth  and  other  minor  surgical  operations  has  proved  that 
the  smaller  dose — one-twelfth  of  a  grain  and  even  less — is  just  as  effective 
in  producing  a  local  anaesthesia  as  is  the  larger  dose  ;  while  by  the  employ- 
ment of  the  smaller  dose  the  dangers  of  developing  constitutional  symp- 
toms are  entirely  overcome,  except  in  those  cases  in  which  there  exists  an 
idiosyncrasy  against  this  drug. 

The  writer  has  found  from  a  large  experience  with  cocaine,  both  in  the 
extraction  of  teeth  and  in  surgical  operations,  sometimes  of  considerable 
magnitude,  like  the  extirpation  of  cancerous  growths  of  the  lips  and  jaws, 
that  a  one  or  two  per  cent,  solution  of  cocaine  is  just  as  efdcient  as  a  four 
or  even  a  ten  per  cent,  solution.  When  the  area  to  be  anaesthetized  is 
large  and  there  is  a  possibility  of  exceeding  a  medium  dose,  a  one  per 
cent,  solution  may  be  employed.  In  extracting  teeth,  two  to  three  minims 
of  a  two  per  cent,  solution  should  be  injected  upon  each  side  of  the  jaw, 
care  being  taken  to  keep  the  needle  close  to  the  alveolar  process,  as  by  this 
method  better  results  are  obtained  than  when  the  injection  is  made  nearer 
the  external  surface.  In  operations  for  the  removal  of  tumors,  a  one  per 
cent,  solution  can  be  used,  but  double  the  quantity  employed,  and  the  in- 
jections made  at  several  different  points.  The  one-twelfth  of  a  grain  dis- 
solved in  a  drachm  of  sterilized  water  is  more  efficient  than  the  same  dose 
in  one-half  the  quantity  of  the  menstruum. 

By  using  a  standard  solution  the  dose  may  always  be  accurately  gauged, 
and  the  possibility  of  an  overdose  being  administered  entirely  obviated. 

The  galvanic  current  as  applied  in  cataphoresis  hastens  the  anaesthetic 
action  of  the  drug  and  makes  it  more  profound.  For  the  methods  of  its 
application  the  reader  is  referred  to  the  chapter  on  Hypersensitive  Dentin, 

Cocaine  solutions  are  liable  to  spoil,  if  kept  for  any  length  of  time,  by 
the  development  of  fungi.  It  therefore  becomes  necessary  to  add  an  effi- 
cient antiseptic  to  solutions  that  are  intended  to  be  permanent,  as  sterili- 
zation by  heat  cannot  be  employed  without  producing  chemic  changes  in 
the  cocaine  which  destroy  its  character.  Boiling  causes  it  to  split  up  into 
methyl,  benzoic  acid,  and  ecgonine.  By  using  a  one-half  per  cent,  solution 
of  carbolic  acid  as  the  vehicle  for  making  the  cocaine  solution  the  devel- 
opment of  fungi  is  entirely  prevented,  and  such  solutions  will  keep  for 
weeks  without  change. 

Burchard  recommends  the  following  prescription  : 

R  Cocainse  hydrochloric!. ,  gr.  |  ; 
Morphinse  sulph. ,  gr.  j\  ; 
Or  atropinse  sulph.,  gr.  yi^  ; 
Trinitrin  (one  per  cent,  solution),  gtt.  i ; 
Acidi  carbolici,  gtt.  i ;  * 

Aquae,  ad  q.  s. 
Sig. — The  above  represents  a  half-syringeful,  and  is  a  full  dose. 

Tropacocaine  is  derived  from  the  small-leaved  coca  of  Java.  It  pos- 
sesses a  decided  advantage  over  cocaine  as  a  local  anaesthetic  in  that  it  is 
considerably  less  toxic  in  its  effects,  has  but  a  slightly  depressant  action 
upon  the  cardiac  functions,  and  is  free  from  any  paralyzing  effect  upon  the 


584  OPERATIVE    DENTISTRY. 

function  of  respiration.  As  an  ansesthetic  it  is  more  rapid  in  its  action 
than  cocaine,  but  it  is  not  so  persistent  in  its  effects.  The  dose  is  from 
one-third  to  two-thirds  of  a  grain.  It  is  made  in  solution  with  sterilized 
water,  and  the  drug  is  of  itself  slightly  antiseptic. 

Eucaine. — Eucaine  hydrochlorate  ''A"  is  a  synthetic  body  of  similar 
chemical  constitution  as  cocaine,  and  the  observed  similarity  in  this  re- 
spect was  the  means  of  causing  experimentation  with  it  as  to  its  value  as 
an  ansesthetic  and  mydriatic.  It  is  a  white,  neutral,  crystalline  powder, 
soluble  in  ten  parts  of  cold  water,  about  nine  per  cent.  It  is  preferred  by 
many  ophthalmologists  to  cocaine  for  all  purposes  in  which  this  drug  is 
used,  as  its  toxic  effects  are  less  powerful,  while  its  ansesthetic  and  mydri- 
atic powers  are  more  persistent  than  those  of  cocaine. 

Its  physiologic  effect  upon  the  central  nervous  system  is  primarily 
one  of  exaltation,  as  shown  in  a  quickened  heart-beat,  and  secondarily  of 
depression  and  paralysis.  Locally  it  produces  hypersemia  of  the  capilla- 
ries, while  cocaine  produces  ischaemia. 

Solutions  of  eucaine  are  made  in  distilled  water,  and  are  much  more 
stable  than  those  of  cocaine.  Sterilization  by  boiling  does  not  decompose 
the  eucaine.  The  maximum  dose  hypodermatically  is  from  one-fourth  to 
one-half  a  grain.  It  is  employed  in  dental  surgery  in  from  four  to  nine 
per  cent,  solutions.  Solutions  stronger  than  nine  per  cent,  are  not  stable^ 
and  will  separate  crystals  of  eucaine. 

Beta  Eucaine. — Eucaine  hydrochlorate  ''B''  is  a  similar  synthetic  body 
to  eucaine  "A."  It  is  a  white,  neutral  crystalline  powder,  soluble  in  from 
twenty-seven  to  twenty-eight  parts  of  cold  water — three  to  four  per  cent. — 
at  ordinary  room-temperature.  The  toxicity  of  eucaine  "B,"  according  to 
the  experiments  of  Drs.  Dumont  and  Legrand,  is  3.75  less  than  that  of 
cocaine,  and  about  three  times  less  than  eucaine  ''A,"  while  its  anaesthetic 
effect  is  equally  rapid,  but  of  shorter  duration.  It  is  complete  in  from 
three  to  five  minutes,  and  disappears  in  from  ten  to  twenty  minutes. 
Later  experiments  place  the  toxic  effect  of  eucaine  "  B"  at  five  times  less 
than  that  of  cocaine.  It  is  employed  hypodermatically  in  dental  surgery 
in  solutions  of  one-tenth  to  one  per  cent.  The  dose  usually  employed  is 
one  to  two  centigrammes  (one-sixth  to  one-third  of  a  grain)  of  a  one  per 
cent,  aqueous  solution. 

Chloretone  (acetonchloroform,  or  trichlor  tertiary  butyl  alcohol)  is  an- 
other synthetic  compound,  prepared  by  Parke,  Davis  &  Co.,  and  "is 
formed  when  caustic  potash  is  slowly  added  to  equal  weights  of  chloroform 
and  acetone,  and  may  be  isolated  from  this  mixture,  after  the  removal  of 
any  excess  of  acetone  and  chloroform,  by  distilling  with  steam.  Obtained 
in  this  manner,  it  is  a  white,  crystalline  compound,  having  the  odor  of 
camphor.  When  freed  from  water  by  melting  and  allowed  to  cool,  the 
camphoraceous  odor  is  more  pronounced,  and  its  general  appearance  re- 
sembles camphor  more  closely.  It  is  very  soluble  in  chloroform,  acetone, 
strong  alcohol,  ether,  benzine,  and  glacial  acetic  acid,  sparingly  soluble  in 
cold  water  (one  per  cent.),  more  soluble  in  boiling  water.  Dilute  acids 
and  alkalies  are  apparently  without  effect ;  concentrated  sulphuric  acid 
decomposes  it."     (Houghton  and  Aldrich.) 


ANESTHETICS,  LOCAL,    AND    GENERAL.  585 

Chloretone  possesses  hypnotic  and  general  and  local  anaesthetic  proper- 
ties. Its  general  effects  are  mainly  confined  to  the  central  nervons  system, 
differing  only  from  most  of  the  other  hypnotics  and  anaesthetics  of  the  fatty 
acid  series  in  that  it  has  little  or  no  depressing  effect  upon  the  circulatory 
system.  Experimentation  has  shown  that  chloretone  has  a  selective  action 
for  the  central  nervous  system,  as  more  of  this  drug  was  found  in  the  brain 
in  several  instances  than  in  any  other  organ  of  the  body.  Its  local  anges- 
thetic  properties  are  of  a  high  order  and  in  many  respects  resemble  those 
of  cocaine.  It  also  possesses  marked  antiseptic  properties,  and  for  this 
reason  is  free  from  the  objection  sometimes  raised  against  solutions  of 
cocaine  used  for  hypodermatic  injection, — viz.,  that  abscess  and  sloughing 
sometimes  follow  its  employment. 

Chloretone  may  be  used  hypodermatically  in  all  cases  where  cocaine 
can  be  employed,  while  it  is  free  from  the  serious  objection  to  cocaine  in 
that  it  has  little  or  no  depressing  effect  upon  the  action  of  the  heart. 

In  dental  surgery  it  may  be  employed  locally  for  obtunding  hyper- 
sensitive dentin  and  producing  ansesthesia  of  the  dental  pulp  preparatory 
to  its  surgical  extirpation  and  for  the  extraction  of  teeth.  For  obtunding 
hypersensitive  dentin  and  anaesthetizing  the  pulp,  a  solution  is  prepared 
by  mixing  equal  parts  by  weight  of  sulphuric  ether  and  chloretone  crystals. 
This  is  applied  upon  a  pledget  of  cotton  after  the  rubber  dam  has  been 
adjusted.  It  may  also  be  applied  cataphorically  after  the  manner  of 
cocaine. 

For  extracting  teeth,  a  solution  may  be  prepared  by  mixing  fifteen  per 
cent,  of  alcohol  with  eighty-five  per  cent,  of  distilled  water,  and  adding 
enough  chloretone  to  form  a  saturated  solution.  (Leo.)  The  dose  of  this 
solution  (one  per  cent.)  hypodermatically  is  from  fifteen  to  twenty-five 
minims,  and  the  full  local  anaesthetic  effect  is  obtained  in  from  one  to  three 
minutes.  The  dose  of  the  crystals  per  stomach  for  its  anodyne  and  hyp- 
notic effect  is  from  five  to  fifteen  grains,  administered  in  capsules  or 
tablets. 

In  the  employment  of  anaesthetic  drugs  which  are  applied  by  hypoder- 
matic injection,  the  operation  must  be  performed  under  the  strictest  anti- 
septic precautions,  in  order  to  preclude  the  possibility  of  septic  infection. 

The  surface  to  be  punctured  should  be  cleansed  and  rendered  aseptic 
by  repeated  washing  with  one  of  the  common  antiseptic  solutions.  The 
syringe  should  be  of  metal  throughout — cylinder  and  j)iston— so  that  it 
may  be  sterilized  by  boiling  ;  any  other  form  of  syringe  cannot  be  sub- 
jected in  all  of  its  parts  to  such  a  process  without  spoiling  it,  and  unless  so 
treated  it  is  unsafe  to  use.  The  solutions  employed  should  also  be  sterile, 
otherwise  abscesses  may  follow  their  injection  into  the  tissues. 

The  immediate  dangers  from  the  hypodermatic  injection  of  any  of  these 
drugs  are  their  toxic  effects,  and  these  may  develop  at  any  time  and  when 
least  expected.  The  operator  should  therefore  be  prepared  at  all  times 
with  such  remedies  as  may  be  useful  in  combating  these  effects. 

The  symptoms  of  cocaine  poisoning  are  dizziness  and  sense  of  faintness, 
great  pallor,  rapid  and  feeble  pulse,  bluish-white  lips,  cold  perspiration, 
spasmodic  respirations,  and  syncope.     To  combat  these  symptoms,  diffusi- 


586  OPERATIVE    DENTISTRY.    • 

ble  stimulants  are  called  for,  such  as  aromatic  spirit  of  ammonia  and 
whiskey  or  brandy. 

The  aromatic  spirit  of  ammonia  may  be  administered  in  doses  of  from 
one-half  to  one  fluidounce  in  water,  or  whiskey  or  brandy  in  doses  of 
from  one  to  two  fluidounces.  If  the  patient  cannot  swallow,  one-half  of 
this  amount  of  whiskey  or  brandy  may  be  administered  hypodermatically. 
When  the  heart  action  is  very  weak,  sulphate  of  strychnine,  one-hundredth 
of  a  grain  in  a  drachm  of  whiskey,  or  digitalin  in  doses  of  from  one- 
hundredth  to  one-fiftieth  of  a  grain,  may  be  administered  hypodermatically. 
The  tendency  to  fatal  syncope  may  be  combated  by  the  inhalation  of  amyl 
nitrite  in  doses  of  from  two  to  three  minims  dropped  upon  a  napkin  and 
held  under  the  nose.  This  remedy  is  also  put  up  in  tiny  glass  flasks  or 
pearls  containing  three  minims  each,  which  may  be  crushed  upon  a  napkin. 

If  these  measures  fail,  artificial  respiration  and  electricity  should  be 
employed,  and  further  stimulation  of  the  nerve-centres  attempted  by  the 
hypodermatic  injection  of  nitroglycerin  in  doses  of  one-half  minim  to  one 
minim  of  a  one  per  cent,  solution,  increased  to  two  minims  if  necessary. 

GENERAL   ANESTHETICS. 

The  substances  which  are  commonly  used  for  the  purpose  of  producing 
general  anaesthesia  are  chloroform,  ether,  and  nitrous  oxide  gas;  various 
other  substances  have  been  introduced  and  tried  for  the  same  purpose,  but 
none  of  them  has  ever  enjoyed  popular  favor.  Among  these  substances 
may  be  mentioned  amylene  {pental^,  carbon  tetrachloride,  chloral  hydrate,  ethene 
chloride,  hydrohromic  ether  (bromide  of  ethj^l),  and  various  mixtures  of  alco- 
hol and  chloroform,  and  alcohol,  chloroform,  and  ether. 

The  substances  which  are  most  commonly  used  in  the  practice  of  dental 
surgery  are  nitrous  oxide  gas  (N.^O)  and  sulphuric  ether  (C^HJ^O.  Chloroform 
(CHCI3)  is  rarely  used  in  the  extraction  of  teeth  or  other  operations  which 
require  for  their  performance  a  sitting  position,  on  account  of  the  depress- 
ing effect  of  the  drug  upon  the  functions  of  the  heart.  These  dangers  are, 
however,  greatly  lessened  if  the  patient  can  be  kept  in  a  recumbent  posi- 
tion during  the  entire  period  of  anaesthesia.  Infants  and  little  children 
bear  chloroform  better  than  adults,  and  in  many  ways  it  acts  more  kindly 
upon  little  children  than  any  other  anaesthetic.  Chloroform  has  proved 
itself  to  be  so  unsafe  for  dental  operations  upon  adults  that  it  is  rarely 
used  at  the  present  time  for  these  x>urposes.  IS'itrous  oxide  gas  and  ether 
are  so  much  safer,  and  so  completely  fill  the  requirements  of  anaesthetics  in 
both  brief  and  prolonged  operations,  that  there  is  no  need  of  running  the 
risk  of  a  fatal  accident  by  employing  chloroform  when  comparatively  safe 
remedies  may  be  used  in  its  stead. 

Nitrous  Oxide  Gas. — This  substance  is  the  safest  of  all  of  the  anaes- 
thetics employed  for  dental  purposes  that  have  so  far  been  discovered. 
It  suffers  no  chemical  change  at  the  temperature  of  the  body  or  during  its 
inhalation.  Its  only  drawback  is  the  fact  that  the  anaesthesia  produced  by 
it  is  of  such  short  duration — usually  from  thirty  to  sixty  seconds— that  it 
can  be  employed  only  in  momentary  operations,  like  the  extraction  of 
teeth,  the  lancing  of  an  abscess,  or  the  extirpation  of  a  vital  pulp.     For 


ANAESTHETICS,  LOCAL    AND    GENERAL. 


587 


this  reason  it  has  but  little  place  in  general  surgery.  It  has  been  used  in 
operations  for  strabismus,  the  removal  of  small  tumors,  for  painful  exami- 
nations, the  setting  of  a  recent  luxation,  or  the  performance  of  a  tenotomy  ; 
but  in  all  operations  requiring  more  than  a  very  few  minutes  ether  is  to 
be  preferred,  as  with  this  substance  anaesthesia  may  be  maintained  for  an 
hour  or  two  if  required. 

Nitrous  oxide  gas  is  made  by  the  fusion  of  granulated  ammonium  nitrate 
in  a  glass  retort,  the  gas  being  passed  through  three  wash-bottles  contain- 
ing water  and  collected  in  a  small  gasometer. 

The  manufacture  of  the  gas  requires  very  close  attention  to  obtain  it  in 
a  pure  state.  The  most  common  impurities  likely  to  be  found  in  the  gas 
are  chlorine  and  nitric  oxide,  and  for  this  reason  every  sample  of  ammo- 
nium nitrate  used  should  be  tested  for  chlorine  before  using  it,  and  the 
greatest  care  exercised  not  to  allow  the  heat  to  rise  above  482°  F. ,  as  nitric 


Fig.  647. 


Fig.  648. 


oxide  is  given  off  above  this  degree  of  heat.     For  the  comj)lete  process  ot 
its  manufacture  the  reader  is  referred  to  works  on  chemistry. 

Since  the  introduction  of  liquefied  nitrous  oxide  gas  few  dentists 
manufacture  the  gas  for  themselves.  The  liquefied  gas  is  so  universally 
pure,  that  the  dentist  feels  he  can  obtain  a  better  article  than  he  can  manu- 
facture for  himself ;  while  it  is  in  such  a  convenient  form  to  handle,  and 
the  apiDaratus  takes  up  so  little  space  in  the  operating-room,  that  there  is 
no  longer  any  need  of  his  consuming  his  time  in  its  manufacture  or  filling 
his  office  with  a  cumbersome  apparatus. 

Nitrous  oxide  gas,  when  properly  employed,  is  almost,  if  not  entirely, 
free  from  danger,  and  is  rarely  productive  of  those  disagreeable  symptoms 
of  nausea  and  depression  which  so  commonly  follow  the  administration  of 
ether  and  chloroform. 

-  There  are  several  forms  of  apparatus  used  for  administering  nitrous 
oxide,  both  for  that  made  in  the  usual  manner  and  for  the  liquefied  gas. 
Fig.  647  represents  one  of  the  most  commonly  used  office  apparatuses,  while 


588 


OPERATIVE    DENTISTRY 


Fig.  648  represents  a  portable  apparatus  which  may  be  carried  in  the  hand. 
In  the  former  the  condensed  gas  is  discharged  from  the  cylinder  into  a 
gasometer,  and  the  gas  drawn  from  the  gasometer  through  a  flexible  rubber 
tube  and  the  inhaler.  In  the  latter  the  gas  is  discharged  into  a  rubber  bag 
to  which  are  attached  a  flexible  rubber  tube  and  an  inhaler.  The  inhaler  is 
the  most  important  part  of  the  apparatus,  and  should  be  so  constructed  as 

Fig.  649. 


to  admit  or  exclude  air  at  the  will  of  the  operator.  It  should  also  be 
armed  with  a  stop-cock  by  which  the  gas  may  be  turned  off,  and  an  auto- 
matic valve  whereby  the  expired  air  may  be  expelled  and  prevented  from 
entering  and  mixing  with  the  gas  as  it  passes  through  the  inhaler. 

Fig.  649  represents  an  inhaler  with  a  removable  lip-shield,  while  Fig. 
650  represents  an  inhaler  having  a  face-piece  or  hood  which  covers  not  only 

Fig.  650. 


Fig.  651. 


the  mouth,  but  the  nose  as  well.  The  advantage  of  the  former  lies  in  the 
fact  that  when  the  lip-shield  is  removed  the  lips  can  be  lightly  comi^ressed 
around  the  mouth-piece  by  the  fingers  of  the  operator,  and  it  also  gives  a 
full  view  of  these  i^arts,  so  that  the  changes  in  their  color,  as  shown  in  the 
mucous  membrane,  can  be  carefully  watched  and  those  symptoms  noted 
which  indicate  the  lack  of  oxygen  and  the  accumulation  of  carbonic  acid 


AK.^STHETICS,  LOCAL    AND    GENERAL. 


589 


in  the  blood.  Cyanosis  of  the  lips,  stertorous  breathing,  and  jactitation, 
etc.,  are  the  danger  signals.  In  the  latter  instrument  the  face-piece  or  hood 
is  a  serious  disadvantage,  in  that  it  covers  the  mouth  and  nose,  making  it 
impossible  to  watch  the  effects  of  the  gas  upon  the  blood,  while  in  those 
patients  who  wear  a  beard  it  is  imjDossible  to  exclude  the  admission  of  air. 
Occasionally,  as  in  cases  of  harelip,  or  when  the  orbicularis  oris  muscles 
are  so  much  swollen  that  it  is  impossible  to  close  the  lips  about  the  mouth- 
piece, the  hood  becomes  of  great  service.  Fig.  651  shows  the  mechanism 
of  the  inhaler. 

Hewitt's  Method. — Dr.  Hewitt,  of  London,  England,  believing  that 
the  symptoms  of  asphyxia  which  so  often  accompany  the  administration 
of  nitrous  oxide  gas  might  be  overcome  by  the  admixture  of  a  proper 
amount  of  oxygen  with  the  gas,  devised  an  apparatus  by  which  oxygen  can 
be  mixed  with  the  gas  in  various  proportions. 

The  apparatus  (Fig.  652)  consists  of  three  cylinders  of  compressed  gas, 
two  filled  with  nitrous  oxide  and  one  with  oxygen,  the  valves  of  which  are 

Fig.  652. 


under  the  control  of  the  foot  of  the  operator.  Connecting  the  cylinder 
with  the  rubber  inhaliug-bag,  which  is  divided  into  two  compartments  by 
a  rubber  septum,  is  a  double  tube  for  conveying  the  gases  to  the  bag.  To 
the  upper  end  of  the  inhaling-bag  is  attached  a  mixing-chamber,  and  to 
this  is  attached  the  mouth-piece  or  inhaling-tube. 

When  about  to  administer  the  gas,  the  valves  of  the  mixing-chamber 


590 


OPERATIVE    DENTISTRY. 


Fig.  653. 


are  closed.  Oxygen  is  then  let  into  one  compartment  of  the  inhaling-bag- 
until  it  is  nearly-  full  aud  nitrous  oxide  into  the  other.  The  inhaling-tube 
is  then  placed  in  the  mouth  of  the  patient,  who  is  instructed  to  make  long, 

full,  deej),  and  steady  inspirations 
and  expirations,  the  nose  being 
closed  with  the  thumb  and  finger 
of  the  operator,  and  the  valve  of 
the  mixing- chamber  (Fig.  653)  so 
changed  that  only  air  is  breathed 
for  a  few  inhalations.  The  indi- 
cator is  then  pressed  downward  to 
the  notch,  which  cuts  off  the  air, 
and  the  patient  now  breathes  only 
the  pure  nitrous  oxide.  After  a 
few  inhalations  the  indicator  is 
carried  still  further  downward  to 
the  second  notch,  which  permits  the 
passage  of  one  part  of  oxygen  to 
mix  with  the  nitrous  oxide.  If  the 
indicator  is  carried  downward  to  the 
third  notch,  two  parts  of  oxygen  are 
mixed  with  the  nitrous  oxide,  and 
so  on  until  the  patient  receives  the 
amount  of  oxygen  necessary  to  pre- 
vent the  appearance  of  the  symptoms  of  asphyxia.  The  amount  of  oxygen 
required  to  prevent  these  symptoms  varies  considerably  with  each  indi- 
vidual ;  some  require  more,  others  less,  and  the  amount  varies  also  with 
the  stage  of  the  anaesthesia.  The  first  symptom  and  the  best  guide  to  the 
condition  of  asphyxia  is  the  cyanotic  appearance  of  the  lips  and  face. 

Similar  advantages  may  be  gained  by  the  admission  of  atmospheric 
air  in  proper  quantity  and  at  the  right  time  during  the  x3roduction  of 
anaesthesia,  but  it  is  not  possible  to  prolong  the  anaesthesia  for  so  long  a 
period  as  by  the  Hewitt  method. 

EXAMINATION   OF   THE   PHYSICAL   CONDITION   OF   THE   PATIENT. 

Before  administering  a  general  ansesthelic  the  condition  of  the  patient 
should  be  ascertained  by  a  critical  physical  examination,  and  if  there  is 
found  to  be  present  any  serious  functional  or  organic  affection  of  the  heart, 
of  the  lungs,  or  of  the  kidneys,  ether  and  chloroform  are  contraindicated. 
Mtrous  oxide  may,  however,  in  some  of  these  cases  be  used  with  success, 
but  there  can  be  no  positive  assurance  that  a  successful  issue  will  follow  its 
administration.  It  is  better,  therefore,  in  all  such  cases  as  would  naturally 
come  under  the  care  of  the  dental  surgeon  for  operation  in  which  serious 
diseases  of  the  heart,  lungs,  or  kidneys  exist,  to  use  a  stimulant  to  brace 
the  patient  for  the  ordeal  of  the  operation,  rather  than  to  take  the  chances 
of  administering  an  anaesthetic. 

The  shock  incident  to  the  extraction  of  a  tooth  or  the  lancing  of  an 
alveolar  abscess  may  be  prevented  in  great  measure,  if  not  completely,  by 


ANESTHETICS,  LOCAL    AND    GENERAL.  591 

the  administration  of  stimulants  or  anodynes  to  such  patients  as  cannot 
with  safety  take  an  anaesthetic. 

Ether  is  positively  contraindicated  in  bronchial  and  pulmonary  dis- 
eases and  in  diseases  of  the  kidneys,  and  chloroform  in  diseases  of  the 
heart.  For  surgical  operations  which  must  be  performed  to  save  life,  ether 
is  the  safest  anaesthetic  for  patients  suffering  from  functional  or  organic 
disease  of  the  heart,  while  chloroform  is  safest  for  those  suffering  from 
bronchial  and  pulmonary  diseases  and  affections  of  the  kidneys.  If  the 
dentist  does  not  feel  that  he  is  competent  to  decide  the  question  of  the 
physical  condition  of  the  patient,  he  should  consult  with  the  family  physi- 
cian in  relation  to  the  matter,  and  if  the  patient  has  no  family  physician, 
it  is  best  to  divide  the  responsibility  of  the  case  by  calling  in  some  other 
physician  to  make  the  examination  and  administer  the  anaesthetic. 


PRECAUTIONS   AGAINST   ACCIDENTS. 

Anaesthetics  should  never  be  administered  just  after  eating,  as  vomiting 
may  be  induced,  and  as  a  result  particles  of  food  may  be  drawn  into  the 
larynx  on  taking  a  deep  inspiration  and  asphyxia  be  the  result. 

If  nitrous  oxide  is  used,  the  dentist  should  never  assume  the  double 
responsibility  of  administering  the  anaesthetic  and  performing  the  opera- 
tion alone.  An  intelligent  and  capable  assistant  should  always  be  pres- 
ent. If  ether  or  chloroform  is  used,  the  patient  requires  the  undivided 
attention  of  the  person  who  administers  the  anaesthetic,  while  the  operator 
should  not  have  his  mind  distracted  by  the  care  of  the  patient  while  under 
the  anaesthetic.  There  is  also  another  reason  why  in  operating  upon  females 
under  the  influence  of  an  anaesthetic  the  operator  should  not  be  alone,  but 
should  have  another  person  present,  preferably  a  nurse  or  a  friend  of  the 
patient.  I^ot  infrequently  hallucinations  and  erotic  desires  are  stimulated 
by  the  effects  of  the  anaesthetic,  and  the  patient  clings  to  the  delusion  that 
an  indecent  assault  has  been  made  uj^on  her  while  she  was  in  a  helpless 
condition  from  the  anaesthesia.  The  operator,  therefore,  if  he  would  guard 
himself  against  unjust  reproach  and  a  serious  criminal  charge,  should  see 
to  it  that  some  friend  of  the  patient  is  present  during  the  operation. 

Before  beginning  the  administration  of  any  general  anaesthetic,  the 
mouth  should  be  examined  for  the  j)resence  of  artificial  teeth,  especially 
partial  plates,  as  failure  to  take  this  precaution  has  in  several  instances 
resulted  in  a  fatality  from  the  plate  becoming  dislodged  and  falling  into 
the  larynx  or  becoming  lodged  in  the  oesoj)hagus. 

In  the  administration  of  nitrous  oxide  a  mouth-prop  (Fig.  654  or  Fig. 
655)  is  necessary  to  keep  the  mouth  oj)en  during  the  operation.  This 
should  be  applied  before  the  mouth-piece  is  placed  in  position,  so  that 
when  anaesthesia  is  complete  no  time  will  be  lost  in  efforts  to  pry  the  mouth 
oj)en  to  insert  the  prop. 

Props  made  of  wood  or  vulcanite  are  the  best ;  they  should  have  a 
long  string  securely  fastened  around  the  centre  by  which  they  may  be 
withdrawn  if  by  accident  they  should  be  dislodged  and  fall  into  the  fauces. 

Clothing  which  is  tight  at  the  throat  or  the  waist  should  be  loosened, 


592 


OPERATIVE    DENTISTRY. 


that  there  may  be  no  obstruction  to  the  most  perfect  movements  of  breath- 
ing. 

In  the  extraction  of  teeth,  and  particularly  of  roots,  the  operator  should 
use  the  utmost  care  to  prevent  the  tooth  or  root  from  slipping  from  the 
forceps  and  falling  into  the  larynx,  and  when  the  elevator  is  used  to  dis- 

FiG.  ()55. 


Fig.  654. 


Mouth-prop  (Dr.  S.  H.  Guilford  pattern). 


Dr.  Daintree  pattern. 


lodge  a  root,  it  should  be  removed  from  the  mouth  before  another  is 
extracted,  for  if  left  in  the  mouth  it  might  fall  into  the  larynx  or  be  drawn 
in  by  a  quick  inspiration,  and  the  patient  die  from  asphyxia  before  it  could 
be  removed  or  relief  obtained  by  tracheotomy. 


Fig.  656. 


ADMINISTRATION   OF   ETHER. 

In  favorable  cases  which  require  operations  that  consume  more  time 
than  would  be  allowed  by  nitrous  oxide  anaesthesia,  sulphuric  ether  is  the 
safest  and  best  anaesthetic  that  can  be  employed.     This  substance  may  be 

administered  by  means  of  a  cone  (Fig. 
656)  formed  of  a  towel  or  a  folded  news- 
paper, in  which  a  napkin  has  been  folded 
or  a  sponge  has  been  placed  and  secured 
with  an  ordinary  pin  or  a  safety-pin. 
The  napkin  or  sponge  is  saturated  with 
ether,  care  being  taken  not  to  put  on  so 
much  as  to  cause  it  to  drip  upon  the  face 
of  the  patient.  It  is  then  slowly  advanced 
to  the  face  of  the  patient,  allowing  plenty 
of  air  to  be  inspired  with  the  ether  vapor 
until  the  air-passages  become  accustomed 
to  the  irritation  and  the  tendency  to  cough 
has  passed  away.  It  may  then  be  brought 
close  to  the  face  and  all  air  excluded  ex- 
cept that  which  passes  through  the  open 
end  of  the  cone  and  through  the  sponge  or  over  the  surface  of  the  napkin. 
In  this  way  the  patient  receives  a  sufficient  amount  of  oxygen  to  support 
the  functions  of  life,  while  at  the  same  time  the  air  is  thoroughly  im- 


Towel  done  up  as  a  cone. 


ANESTHETICS,  LOCAL    AND    GENERAL. 


593 


pregnated  with  the  ether  vapor,  and  the  patient  is  rapidly  brought  under 
its  influence. 

Various  forms  of  inhalers  have  been  introduced  from  time  to  time  for 
the  administration  of  ether,  the  best  of  which  are  the  Lente  (Fig.  657)  and 
the  AUis  (Fig.  658). 

The  Lente  inhaler  is  a  cone  made  of  sheet  brass,  fitted  with  a  rubber 
air-cushion  around  the  edge  to  exclude  the  air  from  entering  between  the 
cone  and  the  face,  while  the  upper  end  has  an  opening  fitted  with  a  cork- 
stoppered  tube  large  enough  to  admit  sufficient  air.  When  in  use  the 
cone  is  lined  with  a  piece  of  sheet  lint  or  cotton,  held  in  place  by  a  piece 
of  wire  or  whalebone  slipped  in,  and  long  enough  to  curve  upward,  so  as 
to  keep  the  cotton  from  touching  the  face.     The  cotton  lining  is  saturated 


Fig.  658. 


Fig.  657. 


Lente's  inhaler. 


Allis's  inhaler. 


with  ether,  and  the  apparatus  is  ready  for  use.  Additional  ether  may  be 
supplied  through  the  open  tube  without  removing  the  apparatus  from  the 
face,  but  great  care  must  be  exercised  not  to  pour  on  more  ether  than  the 
cotton  will  absorb,  as  there  is  danger  of  its  running  into  the  throat  and 
causing  asphyxia. 

The  Allis  inhaler  "consists  of  a  wire  framework  sufficiently  large  to 
cover  the  lower  part  of  the  face  ;  these  wires  are  parallel,  and  about  one- 
quarter  of  an  inch  apart.  Between  the  wires  and  from  side  to  side  a  strip 
of  muslin  bandage,  two  and  one-half  inches  wide  and  three  yards  long,  is 
passed.  The  wire  frame  is  five  inches  long  by  three  inches  at  its  greatest 
width.  Outside  of  the  wire  frame  there  is  a  covering  of  sheet  brass,  and 
over  this  another  metal  cover  with  a  cushioned  edge  to  fit  over  the  face, 
covering  both  the  nose  and  mouth,  as  shown  in  Fig.  659.  When  ready  for 
use,  the  top  is  left  open  for  the  free  entrance  of  air  and  for  supplying  the 
ether  from  without." 

Many  times,  if  the  confidence  of  the  patient  can  be  secured  beforehand, 
a  tooth  may  be  extracted,  an  abscess  opened,  or  a  pulp  extirpated  before 
the  patient  loses  consciousness,  as  sensation  to  pain  is  lost  long  before  this 
stage  of  complete  ansesthesia  is  reached.  In  serious  operations,  however, 
profound  anaesthesia  is  necessary  in  order  to  prevent  shock  and  to  obtain 
perfect  control  of  the  patient  during  the  operation,  as  struggling  or  the 

38 


594 


OPERATIVE   DENTISTRY. 


spasmodic  contractions  of  the  diaphragm  and  abdominal  muscles  incident 
to  efforts  to  vomit  caused  by  nausea  are  great  hinderances  to  a  delicate 
operation. 

During  the  stage  of  excitement  or  when  the  contractions  of  the  abdo- 
minal muscles  indicate  the  existence  of  a  tendency  to  vomiting,  the  anses- 
thesia  should  be  hastened,  in  order  to  allay  these  symptoms  and  secure 
complete  anaesthesia  as  quickly  as  possible. 

Complete  anaesthesia  may  be  recognized  by  placing  the  surface  of  a 
finger  upon  the  conjunctiva  of  the  eye,  when,  if  sensation  is  not  present,  no 
contraction  of  the  muscles  of  the  lids  will  be  observed.  Complete  relaxa- 
tion of  the  muscles  is  another  indication  of  complete  anaesthesia.  This 
may  be  demonstrated  by  raising  an  arm,  which  will  immediately  fall  if 
complete  relaxation  of  the  muscles  has  taken  place. 

When  the  stage  of  muscular  relaxation  is  reached  there  is  a  tendency 
for  the  lower  jaw  to  drop  and  the  tongue  to  fall  into  the  fauces,  which 

Fig.  659. 


Allis's  aseptible  ether  inhaler,  all  metal. 


by  its  pressure  upon  the  larynx  and  the  glottis  causes  obstruction  to 
breathing.  This  tendency  of  the  jaw  to  drop  may  usually  be  overcome  by 
placing  the  fingers  upon  its  under  side  midway  between  the  angle  and  the 
mental  foramen,  and  bringing  the  teeth  of  the  lower  jaw  in  contact  with 
those  of  the  upper,  and  supporting  it  in  that  position.  If  the  tongue  falls 
into  the  fauces,  it  should  be  grasped  with  the  tongue-forceps  and  with- 
drawn, and  so  held  until  muscular  relaxation  has  passed. 

Dilatation  of  the  pupil  and  stertorous  breathing  are  danger  signals,  in- 
dicating that  the  limit  of  safety  has  been  reached.  The  ether  should  there- 
fore be  withdrawn,  and  the  free  administration  of  atmospheric  air  allowed. 
If  the  respirations  cease  and  cyanosis  of  the  lips  and  face  is  present,  the 
tongue  should  be  quickly  grasped  with  a  tenaculum  or  tongue-forceps, 
and  the  organ  drawn  well  forward  ;  this  oj)ens  the  rima  glottidis  and  allows 
free  entrance  of  air.  If,  however,  breathing  does  not  immediately  begin 
again,  artificial  respiration  must  be  instituted  and  maintained  until  nature 
re-establishes  the  normal  physiologic  process.  Other  methods  which  may 
be  employed  to  resuscitate  the  patient  have  already  been  described  in  an 
earlier  part  of  this  chapter  under  the  head  of  cocaine  anaesthesia. 


CHAPTEE    XLIL 

EXTRACTION   OF   TEETH. 

The  operation  of  extracting  teeth  is  one  which  requires  experience, 
skill,  good  judgment,  and  an  accurate  knowledge  of  the  anatomy  of  the 
teeth  and  of  the  contiguous  parts.  An  operator  who  attempts  to  extract 
teeth  without  this  exact  knowledge  will  prove  himself  a  bungler,  and  be 
the  means  of  causing  great  suffering  and  irretrievable  injury  to  the  integ- 
rity of  the  remaining  teeth  and  to  the  jaws.  For  these  reasons  it  is  very 
important  that  the  operator  thoroughly  understand  : 

1.  The  anatomy  of  the  teeth  and  their  most  common  anomalies. 

2.  The  relations  of  the  roots  of  the  teeth  to  the  jaws. 

3.  The  indications  which  call  for  the  extraction  of  teeth. 

4.  The  selection  of  the  proper  instruments  with  which  to  extract  indi- 
vidual teeth  or  roots. 

5.  The  proper  adjustment  of  the  instrument  to  the  tooth  or  root. 

6.  The  proper  kind  and  direction  of  the  force  to  be  applied,  and  the 
lines  of  least  and  greatest  resistance  of  the  alveoli. 

7.  The  difficulties,  complications,  and  accidents  which  are  liable  to 
occur  in  the  operation. 

The  anatomy  of  the  teeth  and  their  anomalies,  and  the  relations  of  the 
roots  of  the  teeth  to  the  jaws,  have  already  been  discussed  in  Chapter  I., 
to  which  the  reader  is  referred. 

INDICATIONS   WHICH   CALL   FOR   THE   EXTRACTION   OF   TEETH. 

The  indications  for  tooth  extraction  are  dependent  upon  such  varied 
conditions,  both  local  and  general,  that  no  arbitrary  rules  can  be  laid  down 
by  which  to  decide  the  many  questions  involved.  All  that  can  be  done  in 
this  direction  to  assist  the  practitioner  and  the  student  is  to  suggest  those 
conditions  which  most  imperatively  demand  the  operation. 

Deciduous  Teeth. — There  are  certain  conditions  which  demand  the 
extraction  of  the  permanent  teeth  which  do  not  appear  in  relation  with 
the  temporary  teeth  by  reason  of  their  deciduous  nature  and  function. 

The  most  important  conditions  which  call  for  the  extraction  of  the 
deciduous  teeth  are  : 

1.  When  the  teeth  are  the  seat  of  alveolar  abscesses  which  do  not 
respond  to  appropriate  treatment. 

2.  When  from  other  causes  they  are  a  source  of  continued  irritation, 
affecting  the  comfort  or  the  general  health  of  the  patient. 

3.  When  the  retention  of  the  deciduous  teeth  is  causing  the  permanent 
teeth  to  erupt  out  of  their  normal  position. 

4.  When  a  deciduous  tooth  is  retained  long  past  the  normal  period  for 
its  exuviation  by  reason  of  the  non- eruption  of  its  permanent  successor, 

595 


596  OPERATIVE    DENTISTRY. 

and  it  is  becoming  wedged  between  its  immediate  neighbors  as  a  result  of 
the  approximal  inclination  of  these  teeth. 

Permanent  Teeth. — The  most  important  conditions  which  call  for  the 
extraction  of  the  permanent  teeth  are  : 

1.  When  a  tooth  or  roots  of  a  tooth  are  the  subject  of  a  chronic  alveolar 
abscess  which  does  not  respond  to  treatment,  or  when  there  is  in  the  upper 
jaw  an  abscess  which  dischai'ges  into  the  antrum  or  the  nasal  fossa. 

2.  When  a  tooth  is  the  subject  of  an  acute  alveolar  abscess  of  malignant 
type,  which  threatens  to  cause  acute  septiccemia. 

3.  When  a  tooth  is  rendered  useless  from  extrusion  caused  by  the  loss 
of  its  antagonist  and  a  proper  occlusion  cannot  be  restored  by  artificial 
means,  or  it  has  become  very  loose  from  resorption  of  the  alveolar  pro- 
cess or  from  pyorrhoea  alveolaris. 

4.  When  a  tooth  or  the  roots  of  a  tooth  have  become  useless  for  the 
purpose  of  crowning,  bridging,  or  supijorting  a  plate,  by  reason  of  the 
presence  of  fungoid  growths  of  the  pulp  or  the  gum  or  of  their  gradual 
destruction  by  resorption. 

5.  When  a  tooth  is  the  subject  of  hypercementosis  which  causes  a  per- 
sistent neuralgia. 

6.  When  a  tooth  is  the  subject  of  a  persistent  odontalgia  dependent 
upon  pulp-nodules  or  a  pulpitis  which  does  not  respond  to  treatment  and 
is  causing  serious  reflex  or  constitutional  irritation. 

7.  When  an  erupting  tooth  is  retarded  by  reason  of  insufficient  room 
in  the  alveolar  arch  or  the  impingement  of  another  tooth,  and  it  is  causing 
irritation  and  pain  or  acute  deep-seated  abscess  of  the  jaw.  This  applies 
most  often  to  the  third  molars,  particularly  those  of  the  lower  jaw. 

8.  When  it  becomes  necessary  to  sacrifice  certain  teeth  to  i)erfect  the 
alignment  of  the  dental  arch. 

9.  When  the  first  permanent  molars  in  children  under  eleven  or  twelve 
years  of  age — before  the  second  molars  are  erupted — i^resent  with  exposed 
pulps  or  alveolar  abscesses.  Under  such  circumstances  all  of  the  first  per- 
manent molars  had  better  be  extracted,  as  such  a  procedure  will  result  in 
a  more  perfectly  formed  arch  and  a  better  occlusion  than  if  only  the  offend- 
ing tooth  is  removed.  The  writer  is  aware  that  there  has  been  considera- 
ble discussion  upon  the  advisability  of  such  a  course  of  treatment ;  but  he 
believes,  after  many  years  of  experience  and  close  observation  of  the  re- 
sults of  both  of  these  lines  of  treatment,  that  the  best  results  are  obtained 
by  the  extraction  of  all  of  the  first  permanent  molars. 

After  the  second  molars  have  erupted  the  extraction  of  the  first  molars 
is  unadvisable,  except  when  the  teeth  are  causing  serious  local  or  con- 
stitutional irritation,  for  after  their  removal  there  is  a  tendency  for  the 
second  molar  to  tilt  forward,  forming  an  inverted  V-shaped  space  between 
itself  and  the  second  bicuspid,  and  preventing  a  normal  occlusion  of  the 
mesial  cusps. 

10.  When  it  is  necessary  to  remove  certain  sound  teeth  preparatory  to 
inserting  an  artificial  denture. 

Under  such  circumstances  the  teeth  that  should  be  removed  are  :  (1)  all 
roots  which  would  be  covered  by  the  denture,  except  those  which  might  be 


EXTRACTION    OF    TEETH.  597 

utilized  to  carry  a  crown  or  form  an  abutment  for  a  bridge  ;  (2)  all  teeth 
which  have  been  rendered  unsightly  or  loose  by  reason  of  the  resorption  of 
the  gums  and  the  alveolar  processes  ;  (3)  all  teeth  that  have  become  so  far 
extruded  from  their  alveoli  as  to  render  it  impossible  to  place  occluding 
artificial  teeth  in  the  opposing  jaw  ;  (4)  a  single  tooth  or  two  teeth  standing 
together,  when  they  are  the  only  teeth  remaining  in  the  upper  jaw.  This 
applies  particularly  to  the  incisors,  cuspids,  and  bicuspids.  Molars  may 
often  be  left  with  advantage  if  they  have  occluding  natural  teeth  ;  (5) 
when  one  tooth  remains  upon  either  side  of  the  upper  jaw — if  they  are  in 
good  position  and  of  proper  shape  to  receive  a  clasp  or  give  support  to  the 
plate — they  should  not  be  extracted  ;  (6)  when  a  single  tooth  remains  in 
the  lower  jaw,  or  a  single  tooth  upon  either  side,  it  is  advisable  to  retain 
them,  especially  if  the  patient  is  about  to  have  inserted  the  first  lower 
plate,  as  such  teeth  are  valuable  for  supporting  the  denture  by  means  of 
clasps,  until  such  time  as  the  patient  becomes  accustomed  to  it. 

GENERAL   CONDITIONS   UNFAVORABLE   TO   EXTRACTION. 

Certain  systemic  conditions  are  generally  regarded  as  unfavorable  to 
the  extraction  of  teeth,  for  the  reason  that  the  operation  may  under  these 
circumstances  aggravate  an  existing  morbid  condition,  set  in  operation  a 
train  of  unfavorable  symptoms,  or  establish  a  dangerous  and  perhaps  fatal 
complication. 

The  systemic  conditions  which  are  most  liable  to  cause  unfavorable 
results  from  the  extraction  of  teeth  are  : 

I.  General  debility. 

II.  Nervous  irritability. 

III.  Organic  disease  of  the  heart. 

IV.  EiDilepsy. 

Y.  Hemorrhagic  diathesis. 
VI.  Pregnancy. 

I.  General  Debility. — This  is  a  condition  which  greatly  predisposes 
the  individual  sufiering  from  it  to  nervous  depression  and  shock.  In  a  large 
majority  of  these  cases  the  vital  forces  are  depressed,  the  nervous  system  is 
in  an  irritable  condition,  and  the  heart  action  weak.  It  therefore  becomes 
necessary  in  these  cases  to  prescribe  tonic  treatment  in  the  form  of  iron, 
quinine,  and  strychnine,  to  prepare  the  patient  for  the  ordeal  of  the  opera- 
tion. If,  however,  an  immediate  operation  is  imperatively  demanded, 
stimulants  should  be  administered  and  the  operation  performed  under  an 
anaesthetic. 

II.  Nervous  Irritability. — General  nervous  irritability  may  be  an 
inherited  condition  or  diathesis,  or  one  which  is  the  result  of  morbid  con- 
ditions of  the  system  induced  by  disease,  great  nervous  strain,  overwork, 
and  such  like  circumstances.  In  either  case  the  affection  is  a  manifestation 
of  a  debilitated  condition  of  the  nerve-centres  calling  for  general  tonic 
treatment,  such  as  that  just  indicated,  to  build  up  the  system  ;  and  seda- 
tives, such  as  potassium  bromide,  asafetida,  and  valerianate  of  ammonium, 
to  control  the  more  irritable  nervous  manifestations.    Operations  upon  such 


598  OPERATIVE    DENTISTRY. 

individuals  not  infrequently  result  in  severe  shock  to  the  nervous  system, 
resulting  in  chorea,  hysteria,  or  more  serious  nervous  affections. 

III.  Organic  Disease  of  the  Heart. — Inorganic  disease  of  the  heart 
in  any  of  its  many  forms, — hypertrophy,  fatty  degeneration,  valvular  in- 
sufficiency, etc., — there  is  great  danger  of  shock  in  even  trivial  operations. 
It  therefore  becomes  necessary,  whenever  the  operation  of  tooth- extraction 
is  imperatively  demanded,  that  every  precaution  be  taken  to  guard  against 
shock  and  its  possible  fatal  termination.  The  nervous  excitement  and 
fright  incident  to  the  contemplation  of  the  operation  in  individuals  suffer- 
ing from  a  weak  heart  are  sometimes  sufficient  to  produce  fatal  shock.  For 
these  reasons  the  dental  practitioner  should  never  permit  himself  to  oper- 
ate upon  such  individuals  without  the  knowledge  and  co-operation  of  the 
patient's  family  physician.  Such  an  association  is  a  safeguard,  in  case  of  a 
serious  or  fatal  termination  of  the  operation,  against  unjust  criticism  or  a 
suit  for  supposed  malpractice. 

Whenever  a  tooth  has  to  be  extracted  for  a  person  suffering  from  any 
organic  heart  affection,  it  becomes  necessary  to  administer  cardiac  stim- 
ulants, such  as  whiskey  or  brandy,  aromatic  spirit  of  ammonia,  digitalis, 
strychnine,  or  a  one  per  cent,  solution  of  nitroglycerin.  To  obtain  the 
best  results,  some  one  of  these  agents  should  be  prescribed  an  hour  or  two 
before  the  contemplated  operation. 

The  operator  who  is  thoroughly  prepared  for  all  emergencies  will  have 
a  hypodermic  syringe  charged  with  a  tablet  containing  one-fiftieth  of  a 
grain  of  digitalis  or  one-fiftieth  of  a  grain  of  strychnine  sulphate  dissolved 
in  one  drachm  of  whiskey  or  brandy,  or  with  the  following  combination 
(also  put  up  in  tablet  form  by  Nelson,  Baker  &  Co.,  of  Detroit,  Mich.). 

R     Digitoxin,  gr.  ^^  ; 
Nitroglycerin,  gr.  ^i^  ; 
Strychnine  sulph.,  gr.  j^^. 
Dissolve  in  one  drachm  of  distilled  water. 

This  combination  is  an  exceedingly  efficient  remedy  in  cases  of  threat- 
ened heart  failure,  shock,  or  collapse,  and  should  find  a  place  in  all  emer- 
gency outfits. 

IV.  Epilepsy. — Individuals  who  are  so  unfortunate  as  to  be  the  sub- 
jects of  epilepsy  may  be  prepared  for  the  operation  by  the  administration 
of  large  doses  of  potassium  bromide,  which  will  in  many  cases,  for  the 
immediate  time  at  least,  prevent  or  mitigate  the  severity  of  an  attack. 
Nitrite  of  amyl,  if  applied  during  the  convulsion,  will  sometimes  cut  the 
attack  short.  The  nervous  condition  of  these  poor  unfortunates  is  such 
that  anxiety,  fear,  or  the  shock  of  an  operation  is  prone  to  bring  on  an 
attack  ;  it  is  therefore  unwise  for  the  dentist  to  undertake  the  extraction  of 
a  tooth  without  the  presence  of  the  family  physician  or  some  other  medical 
adviser.  In  case  an  attack  comes  on,  all  that  can  be  done  is  to  place  the 
patient  in  the  recumbent  position,  protect  him  against  injury  during  the 
paroxysm,  and  prevent  the  laceration  of  the  tongue  and  other  soft  tissues 
of  the  mouth  from  the  spasmodic  closing  of  the  jaws.     This  may  be  ac- 


EXTRACTION    OF    TEETH.  599 

complished  by  placing  a  piece  of  soft  rubber  between  the  teeth,  or  a  roll 
of  bandage  or  other  such  material. 

V.  Hemorrhagic  Diathesis.— The  hemorrhagic  diathesis  is  due  to 
deficient  muscular  tone  in  the  coats  of  the  blood-vessels,  and  to  a  lack  of 
a  normal  coagulability  of  the  blood.  This  diathesis  may  be  hereditary  or 
acquired,  and  it  usually  first  shows  itself  at  about  the  period  of  second 
dentition.  It  is  a  condition  which  often  causes  great  anxiety  and  alarm  to 
the  operator,  the  patient,  and  the  friends,  as  many  cases  of  fatal  hemorrhage 
following  tooth-extraction  in  these  individuals  have  been  recorded.  When 
the  operator  is  aware  of  the  diathesis  he  can  usually,  by  appropriate  treat- 
ment instituted  a  few  days  before  the  contemplated  operation,  control  the 
tendency  to  hemorrhage  by  improving  the  tone  or  contractility  of  the 
blood-vessels  and  restoring  the  normal  coagulability  of  the  blood. 

A  pill  containing  from  ten  to  twenty  grains  of  gallic  acid  and  one  grain 
of  opium  may  be  administered  after  each  meal  for  three  days,  or  the  fluid 
extract  of  ergot  may  be  given  in  doses  of  from  twenty  drops  to  one  flui- 
drachm  every  two  to  four  hours  on  the  day  previous  to  the  operation. 
Ergot,  however,  must  not  be  administered  to  pregnant  females,  on  account  of 
the  danger  of  producing  an  abortion. 

VI.  Pregnancy. — Women  who  are  performing  the  functions  of  men- 
struation, gestation,  or  lactation  should  as  far  as  possible  be  shielded  from 
all  operations. 

During  the  period  of  menstruation  most  women  are  in  a  peculiarly 
nervous  condition,  and  much  more  susceptible  to  irritation  and  shock  than 
at  other  periods.  Vicarious  menstruation  from  the  alveolus  of  a  recently 
extracted  tooth  has  also  been  recorded. 

Many  cases  of  premature  labor  have  been  placed  on  record  as  the  result 
of  shock  from  the  extraction  of  a  tooth,  while  congenital  deformities  and 
monstrosities  have  been  charged  to  the  same  cause.  A  very  slight  nervous 
or  mental  shock  is  sufficient  in  some  women  to  produce  premature  labor, 
while  in  others  even  a  severe  shock  makes  no  impression.  It  is  safer, 
however,  under  all  circumstances  requiring  operation  upon  pregnant 
women  to  administer  a  general  anaesthetic,  and  thus  prevent  the  shock 
which  would  be  likely  to  occur  from  the  operation. 

During  lactation  mental  anxiety,  nervous  irritation,  and  shock  are 
liable,  through  some  peculiar  action  of  the  nervous  system,  so  to  change 
the  character  of  the  lacteal  fluid  as  to  make  it  unfit  for  the  nourishment  of 
the  infant,  and  in  some  cases  to  render  it  absolutely  poisonous.  Carpenter  * 
records  a  case  of  this  character  in  which  immediate  death  of  the  child 
followed  the  taking  of  the  breast  of  a  nursing  mother  who  had  sufiered 
great  mental  agitation.  These  occurrences  have  been  explained  in  part 
by  the  discovery  of  Dr.  Victor  C.  Vaughn,  of  Michigan  University,  who 
found  that  under  certain  fermentative  changes  a  poisonous  ptomaine,  which 
he  has  termed  tyrotoxicon,  is  formed  in  milk  and  cheese,  and  also  in  ice- 
cream. 

*  Physiology,  1862,  p.  742. 


600 


OPERATIVE    DENTISTRY. 


INSTRUMENTS  USED   IN  THE  OPERATION  OF   EXTRACTING. 

An  examination  of  the  mouth  and  of  the  tooth  to  be  removed  should 
always  be  made  before  any  steps  are  taken  in  the  operation.  For  this 
purpose  a  mouth-mirror  (Fig.  660)  and  a  curved  probe  or  explorer  are 
necessary. 

Fig.  660. 


Mouth-mirror. 

Gum-lancets  (Fig,  661)  are  employed  in  some  cases  to  dissect  the  gum 
from  around  the  cervix  of  the  tooth  prior  to  the  adjustment  of  the  extract- 
ing instrument.  These  cases  are  represented  by  the  third  molars,  teeth 
which  stand  alone,  and  roots  which  are  buried  more  or  less  completely 

Fig.  661. 


Gum-lancet. 

by  overlying  gum-tissue.  In  all  other  cases  the  use  of  the  gum-lancet  is 
rarely  indicated,  provided  the  beaks  of  the  forceps  are  made  sharp,  so 
that  they  will  cut  their  way  through  the  margin  of  the  gum  as  the  in- 
strument is  pushed  towards  the  alveolar  border. 

Fig.  662. 


Curved  scissors  (Fig.  662)  are  also  necessary  to  a  complete  extracting 
outfit,  and  should  be  at  hand  for  severing  any  portion  of  gum-tissue  that 
might  be  found  adherent  to  the  cervix  of  the  tooth. 


EXTRACTION   OF   TEETH.  gQl 

Month-props  and  gags  (Figs.  663  and  664)  should  be  employed  when  a 
general  anesthetic  is  administered,  the  object  being  to  obviate  the  neL 
sity  of  having  to  open  the  mouth  forcibly  before  the  tooth  can  be  reached 
and  to  conserve  valuable  time,  which  is  an  exceedingly  important  con- 
sideration when  nitrous  oxide  gas  is  used.     (See  also  those  on  page  592.) 

^^«-  6^3.  Fia.  664. 


Mouth-prop. 

Mason's  gag. 

../^Vr'  ''i^^''  ^^^''''  ^^^  '^^'^^^  ^^  ^«^^^^^d  ^ith  rubber  tubing,  to 
prevent  them  from  slipping  or  causing  injury  to  the  teeth.  The  jaws  of 
the^  gag  are  separated  by  turning  the  milled  nut  downward.  The  curve 
of  the  jaws  of  the  instrument  is  such  that  the  handles  extend  backward 

Fig.  665. 


Warren's  screw-gag. 

under  the  lobe  of  the  ear,  and  are  therefore  entirely  out  of  the  way  of  the 
operator.  "^ 

In  adjusting  the  gag,  its  jaws  should  be  placed  between  the  molar  teeth 
upon  the  side  of  the  mouth  opposite  to  that  where  the  operation  is  to  be 
performed. 

The  screw-gag  (Fig.  665)  is  an  exceedingly  useful  instrument  for  opening 

Fro.  666. 


Tobolt's  laryngeal  forceps. 


or  extending  the  jaws  in  cases  of  trismus  caused  by  inflammation  and 
swelling.     Its  application  needs  no  explanation. 

A  laryngeal  forceps  (Fig.  666)  is  also  a  necessary  part  of  a  complete 
extraction  outfit.     In  case  a  tooth  or  a  fragment  of  one  should  fall  into 


602 


OPEEATIVE    DENTISTRY. 


the  fauces  beyond  the  reach  of  the  finger,  this  instrument  would  be  most 
valuable  for  its  removal. 

The  instruments  which  are  employed  for  the  extraction  of  teeth  are 
the  turnkey,  forceps,  and  elevators. 

Turnkey.— The  turnkey,  which  for  many  years  was  the  only  instrument 
employed  in  the  extraction  of  teeth,  has  at  the  present  time  been  almost 
entirely  discarded.    It  is,  however,  a  very  serviceable  instrument  in  certain 

cases  where  the  crown  of  a  molar 
Fig.  667.  ]2as  been  broken  away  by  caries 

or  accident  to  a  point  beneath  the 
gum,  upon  the  buccal  or  lingual 
side  only,  while  the  remaining 
portion  is  strong.  Such  cases  offer 
great  difficulties  to  their  extrac- 
tion with  the  forceps,  which  either 
slip  off  or  carry  away  the  remain- 
ing portion  of  the  crown,  while 
it  is  often  impossible  to  remove 
them  with  an  elevator.  The  ap- 
plication of  the  turnkey  (Fig.  667) 
to  such  teeth  converts  a  difficult 
operation  into  a  simple  one.  This  is  accomplished  by  placing  the  fulcrum 
upon  the  gum  upon  the  side  of  the  tooth  which  has  been  broken  away, 
and  the  claw  upon  the  opposite  side  of  the  tooth  at  the  margin  of  the  gum. 
This  permits  a  proper  direction  of  the  force  applied,  and  admits  of  an  easy 
and  natural  removal  of  the  tooth. 

Forceps. — In  these  days  of  aseptic  surgery  all  forceps  should  be  made 
in  such  a  manner  that  they  may  be  taken  apart,  as  this  gives  a  better 
opportunity  for  thorough  sterilization.  Fig.  668  shows  an  instrument  of 
this  character,  the  joint  of  which  is  very  simple  in  construction,  strong, 
and  easily  cleansed. 

Fig.  668. 


Turnkey. 


Aseptic  forceps. 


The  heaks  of  the  forceps  should  be  of  such  shape  as  to  fit  as  large  a  sur- 
face as  possible  of  the  cervix  of  the  tooth  for  which  they  are  constructed, 
without  pressing  too  hard  upon  the  cervix  or  t\iQ  crown.  If  the  pressure 
comes  too  hard  upon  the  crown,  it  is  liable  to  be  crushed ;  while  if  the 


EXTRACTION    OF    TEETH. 


603 


curve  of  the  beaks  is  so  great  that  the  terminal  edges  grip  the  cervix  only, 
there  is  danger  of  fracturing  the  tooth  at  this  point.  This  quite  often  hap- 
pens with  the  use  of  lower  molar  forceps  that  are  improperly  constructed. 
The  terminal  edges  of  the  beaks  should  be  made  sharp,  so  that  when  they 
are  crowded  against  the  cervical  border  of  the  gum  they  will  cut  their 
way,  and  thus  avoid  the  necessity  of  using  the  gum-lancet. 

The  handles  of  all  forceps  should  be  serrated  in  such  a  manner  that 
when  gripped  by  the  hand  they  will  not  slip.  This  is  very  important,  for 
if  any  considerable  pressure  is  i^laced  upon  the  handles  to  keep  them  from 
slipping,  there  is  danger  of  crushing  the  crown  or  cutting  it  off. 

The  curves  of  the  beaks  and  the  handles  must  be  of  such  form  as  to 
permit  a  proper  adjustment  of  the  beaks  to  the  teeth  to  be  extracted,  while 
the  handles  should  not  impinge  upon  the  anterior  teeth  of  the  opposite 
jaw,  and  should  allow  the  force  which  is  applied  to  be  made  in  a  direct 
line  with  the  long  axis  of  the  tooth,  or,  in  other  words,  in  a  line  with  the 
general  direction  of  the  roots. 

Elevators. — -These  instruments  are  devised  for  the  extraction  of  roots 
which  are  too  frail  to  withstand  the  grip  of  the  forceps  or  the  pressure  of 

Fig.  669. 


I' 


Elevators. 

the  turnkey.  In  applying  these, instruments  the  grooved  face  is  adjusted 
to  the  surface  of  the  tooth,  and  the  blade  carried  downward  to  the  alveolar 
process.  Force  is  then  exerted  in  a  direction  to  lift  the  tooth  from  the 
alveolus.  Fig.  669  shows  several  forms  of  elevators,  all  of  which  are 
useful,  and  should  be  found  in  every  complete  extracting  outfit. 

Fig.  670. 


Dental  screw. 


The  dental  screw  (Fig.  670)  is  also  a  valuable  instrument  for  tne 
removal  of  very  frail  roots  in  which  caries  has  followed  the  pulp-canal 
and  converted  the  root  into  a  mere  shell.  This  instrument  is  applied  by 
screwing  it  into  the  cavity  in  the  root  until  the  thread  takes  a  firm  hold 
upon  the  dentin,  when  the  root  is  easily  lifted  from  its  alveolus. 


604  OPERATIVE    DENTISTRY. 

THE  SELECTION  OF  THE  PROPER  INSTRUMENTS  FOR  THE  EXTRACTION 
OF  THE  VARIOUS  CLASSES  OF  TEETH,  THEIR  PROPER  ADJUSTMENT, 
AND   THE   KIND   AND   DIRECTION   OF   THE   FORCE   APPLIED. 

The  teeth,  from  the  stand-point  of  their  proper  extraction,  may  be 
divided  into  seven  classes,  according  to  the  number  and  the  anatomic  form 
of  their  roots. 

The  first  class  includes  the  superior  central  and  lateral  incisors,  which 
have  single,  cone-shaped  roots. 

The  second  class  embraces  the  inferior  central  and  lateral  incisors, 
which  have  single,  considerably  flattened,  cone-shaped  roots. 

The  third  class  comprises  the  superior  and  inferior  cuspids,  which, 
have  single,  very  long,  slightly  flattened,  cone-shaped  roots. 

The  fourth  class  includes  the  superior  and  inferior  bicuspids,  which 
have  single,  sometimes  bifurcated,  flattened,  cone-shaped  roots. 

The  fifth  class  comprises  the  superior  first  and  second  molars,  which, 
have  three  cone-shaped  roots, — two  buccal  and  one  lingual. 

The  sixth  class  embraces  the  inferior  first  and  second  molars,  with  two 
flattened,  cone-shaped  roots, — one  mesial  and  one  distal. 

The  seventh  class  includes  the  superior  and  inferior  third  molars, 
which  may  have  either  a  single  cone-shaped  root  that  curves  backward  or 
multiple  roots. 

Fig.  671  shows  the  relation  of  the  teeth  to  the  alveolar  process,  and 
Fig.  672  shows  the  form  and  number  of  the  roots  of  the  teeth  and  their 
deeper  relations  to  the  alveolar  processes. 

First  Class. — In  the  extraction  of  teeth  of  thejirst  class,  the  operator 
should  stand  upon  the  right  side  of  the  patient,  who  is  seated  in  the 
operating- chair  with  the  head  thrown  well  back  and  supported  between 
the  chest  and  the  left  arm  of  the  operator,  and  the  lips  shielded  from 
injury  by  the  fingers  of  his  left  hand.  The  forceps  selected  for  the  opera- 
tion should  be  straight,  as  shown  in  Figs.  673  and  674.  The  instrument 
shown  in  Fig.  673  is  intended  for  the  extraction  of  the  superior  central 

Fig.  673. 


Superior  central  incisor  forceps. 

incisors,  but  it  is  equally  adapted  for  the  extraction  of  the  superior  cuspids. 
The  forceps  is  adjusted  to  the  tooth  by  grasping  the  handles  loosely  with 
the  right  hand,  with  the  little  finger  between  the  handles.  This  gives 
control  of  the  opening  and  closing  of  the  jaws  of  the  instrument,  and 
permits  the  regulation  of  the  force  applied  in  grasping  the  tooth,  which  is 
of  considerable  importance  in  extracting  a  tooth  much  weakened  by  caries. 
The  beaks  of  the  forceps  are  then  crowded  well  beyond  the  cervix  of  the 


Flii.  071. 


Fig.  672. 


EXTRACTION    OF   TEETH 

oUo 
tooth,  and  in  so  doinsr  cut  their  w«v  in  fii^  ^^       ^       ■,      . 

rotation  fail  to  dislod<.e  the  tooth  n  I  7  .  .^^*^  ''"'^^"^-  ^'^^^^^^ 
K.  ■  ^  ^r  '^'  ^^*'^  ^^^  '^'^oth,  a  forward  and  backward  movement-,  nm^ 
be  given  to  the  forceps,  combined  with  rotation.  movement  may 

Fig.  674. 


Superior  lateral  incisor  forceps. 


of  th—^riT"  r'' """' ""'''  """^^'  ""'P'^y'^'i  '<"  '^^  •'^action 

01  the  superioi  lateral  mcisors.     The  adjustment  of  the  instrument  and 

he  apphoataoo  of  force  are  the  same  a.  for  the  extraction  of  the  supc'or 

central  mcisors.  »upeuor 

y.  ^f/°^^^^l^^s— In  extracting  teeth  of  the  second  ckm,  the  operator 
should  stand  upon  the  right  side  of  and  a  little  behind  the  patient,  "hose 

Fig.  675. 


Inferior  incisor  forceps,  full  curve. 

lower  jaw  is  supported  with  his  left  hand,  and  the  lips  shielded  with 
the  hngers  of  the  same  hand.  The  forceps  shown  in  Figs.  675  and  676  are 
most  admirably  adapted  for  the  removal  of  the  inferior  central  and  lateral 


Fig.  676. 


Inferior  incisor  forceps,  narrow  beaks,  full  curve. 

incisors,  while  the  hawk-bill  forceps  shown  in  Fig.  677,  and  the  half-curved, 
narrow-beak  forceps  shown  in  Fig.  678,  are  useful  in  removing  very  narrow 
inferior  central  incisors  and  other  inferior  teeth  with  single  roots  which, 
by  reason  of  an  irregularity  in  their  position,  prevent  the  application  of 


6U6  OPERATIVE    DENTISTRY. 

the  broader-beaked  instruments  ordinarily  used  for  their  extraction.     The 
direction  of  the  force  which  should  be  applied  in  the  removal  of  these 

Fig.  677. 


Inferior  incisor  forceps,  hawk-bill. 
Fig.  678. 


Inferior  incisor  forceps,  half  curve. 

teeth  w,  forward  and  backward,  to  break  up  their  attachments  to  the  alveo- 
lus, and  in  an  upward  direction  to  lift  them  out. 

Third  Class. — The  i30sitions  of  the  patient  and  the  operator  and  the 
means  of  supporting  the  head  and  protecting  the  lips  are  the  same  as 
described  for  the  first  class.     The  forceps  best  adapted  to  the  extraction  of 

Fig.  679. 


Superior  cuspid  forceps. 
Fig.  680. 


Superior  cuspid  and  bicuspid  forceps. 

the  superior  cuspids  are  those  shown  in  Figs.  679,  680,  and  681.  Inasmuch 
as  these  teeth  have  the  longest  roots  and  are  the  most  firmly  fixed  in  their 
alveoli  of  all  the  teeth,  it  requires  more  skill  and  strength  to  extract  them 
than  any  other  teeth  in  the  mouth,   and  consequently  the  instruments 


EXTEACTION    OF    TEETH. 


607 


used  for  this  purpose  must  be  very  strong.  In  adjusting  the  forceps, 
the  beaks  should  be  forced  upward  and  beyond  the  cervix  as  far  as  the 
border  of  the  alveolus,  the  tooth  firmly  gripped,  and  force  applied  by  a 
combined  rotary^  forward,  and  backward  movement.  The  attachments  of 
the  tooth  are  thus  broken  up,  and  it  is  removed  from  its  alveolus. 

The  position  of  the  patient  for  the  extraction  of  the  inferior  cuspids 
should  be  as  nearly  upright  as  possible,  with  the  chin  well  down  upon  the 
chest,  while  the  position  of  the  operator  should  be  upon  the  right  side  and 

Fig.  681. 


Superior  cuspid  and  bicuspid  forceps. 


Fig.  682. 


Inferior  cuspid  and  bicuspid  forceps. 
Fig.  683. 


Inferior  cuspid  and  bicuspid  forceps,  full  curve. 

slightly  behind  the  patient.  The  chair  should  be  low  enough  to  give 
him  full  opportunity  to  apply  force  in  an  upward  direction,  while  at  the 
same  time  it  is  applied  in  a  forward  and  backward  direction.  The  roots 
of  these  teeth  are  so  much  flattened  laterally  that  rotation  cannot  be  suc- 
cessfully employed.  The  forceps  best  adapted  for  the  extraction  of  these 
teeth  are  shown  in  Figs.  682  and  683. 

Fourth  Class.— The  forceps  which  are  best  adapted  for  the  extraction 
of  the  superior  bicuspids  are  the  same  as  those  used  for  the  removal  of 
the  superior  cuspids. 

The  positions  of  the  patient  and  the  operator,  the  support  of  the  head^ 
and  the  protection  of  the  lips  are  the  same  as  described  for  the  removal  of 


608 


OPERATIVE   DENTISTRY. 


teeth  of  the  first  class.  The  instrument  is  adjusted  by  grasping  the  tooth 
at  the  cervix  and  crowding  the  beaks  upward  to  the  border  of  the  alveolus, 
then  firmly  grij)ping  the  handles  of  the  forceps  and  applying  force  for 
extraction  in  a  combined /orwar^,  backward,  and  downward  direction. 


Fig.  684. 


Inferior  bicuspid  forceps,  half  curve. 


In  extracting  the  inferior  Mcuspids  the  positions  of  the  patient  and 
operator,  the  position  of  the  chair,  and  the  protection  of  the  lips  are  the 
same  as  described  for  the  extraction  of  the  inferior  cuspids.     The  instru- 


FiG.  685. 


Inferior  bicuspid  forceps,  full  curve. 

ments  best  adapted  for  the  extraction  of  these  teeth  are  shown  in  Figs.  684 
and  685.  The  application  of  force  should  be  in  a  combined  forward,  hack- 
ward,  and  upward  direction. 

Fifth  Class. — The  superior  first  and  second  molars,  by  reason  of  the 
number  and  form  of  their  roots,  often  require  considerable  strength  to 
dislodge  them  from  their  alveoli.  The  beaks  of  the  forceps  which  are  used 
for  the  extraction  of  these  teeth  require  to  be  especially  made  to  conform 
to  the  shape^of  the  teeth  at  the  cervix.  The  outer  or  buccal  beak  of  the 
forceps  is  constructed  with  a  projecting  point  in  the  centre,  which  fits 
into  the  sulcus  formed  by  the  bifurcation  of  the  buccal  roots,  while  the 
inner  beak  is  made  plain,  to  fit  the  convexity  of  the  lingual  surface  of  the 
lingual  (palatal)  root.  These  instruments  are  usually  made  in  pairs,  right 
and  left,  to  suit  the  form  of  the  teeth  upon  opposite  sides  of  the  mouth. 
The  jaws  and  handles  should  be  so  curved  as  to  make  it  possible  to  grasp 
these  teeth  and  not  have  the  handles  come  in  contact  with  the  corner  of 
the  mouth  or  the  lips.  Fig.  686  shows  the  form  of  these  forceps.  An- 
other form  of  forceps  is  that  shown  in  Fig.  687.  These  instruments  are 
bayonet-shaped,  and  have  the  beaks  like  those  just  described,  one  adapted 
for  the  teeth  of  the  right  side,  the  other  for  the  left.  The  bayonet  form 
given  to  these  instruments  makes  them  very  valuable  for  the  extraction 
of  these  teeth  when  the  oral  commissure  is  very  small. 


EXTRACTION    OF   TEETH. 


609 


In  adjusting  either  of  these  instruments  to  the  tooth  the  beaks  are 
made  to  grasp  the  tooth  at  the  cervix,  the  pointed  beak  being  inserted 
between  the  buccal  roots,  and  the  instrument  forced  upward  to  the 
border  of  the  alveolus.     The  handles  are  then  firmly  gripped,  and  the 


Fig.   686. 


Fig.  687. 


Right.  Left. 

Superior  first  and  second  molar  forceps. 
Harris.) 


(Dr. 


Right.  Left. 

Superior  first  and  second  molar  forceps  (bayonet 
shape). 


tooth  rocked  by  a  backward  and  forward  movement  until  it  is  loosened  in 
its  alveoli,  when  force  may  be  applied  in  a  downward  direction,  and  the 
tooth  dislodged. 

Sixth  Class.— The  inferior  first  and  second  molars  have  but  two  roots, 
and  do  not,  therefore,  as  a  rule,  require  so  much  force  to  extract  them  as  do 

Fig.  688. 


Inferior  first  and  second  molar  forceps  (universal),  either  side.    (Dr.  Harris.) 

the  superior  molars.     The  beaks  of  the  forceps  which  are  used  for  the  ex- 
traction of  these  teeth  are  each  made  with  a  projecting  point  which  fits 

39 


610 


OPERATIVE   DENTISTRY. 


into  the  buccal  and  lingual  sulci  formed  by  tbe  bifurcation  of  the  root. 
The  jaws  and  handles  of  the  forceps  are  also  curved  in  such  a  manner  as 
to  permit  the  tooth  to  be  grasped  while  the  handles  remain  clear  of 
the  lips  and  of  the  corner  of  the  mouth.     Fig.  688  shows  an  instrument 


Fig.  689. 


Inferior  right  first  and  second  molar  forceps. 
Fig.  690. 


Inferior  left  first  and  second  molar  forceps. 
Fig.  691. 


Inferior  universal  first  and  second  molar  forceps.    (Dr.  Hutchinson.) 
Fig.    692. 


Inferior  universal  cow-horn  forceps,  first  and  second  molars. 

which  is  adapted  for  use  ux)on  either  side  of  the  mouth,  while  in  Figs. 
689  and  690  are  seen  forceps  made  in  right  and  left  forms. 

Fig.  691  shows  another  form  of  universal  lower  molar  forceps,  the 
invention  of  Dr.  Hutchinson,  while  Fig.  692  illustrates  a  universal  cow- 
horn  lower  molar  forceps.  These  are  also  made  for  the  right  and  left  sides 
(Figs.  693  and  694). 


EXTRACTION    OF    TEETH.  611 

The  position  of  the  patient,  that  of  the  operator,  and  the  method  of 
protecting  the  lips  are  the  same  as  in  the  extraction  of  the  inferior 
cuspids  and  bicuspids. 

Fig.  693. 


Inferior  left  first  and  second  molar,  cow-horn  forceps. 

In  adjusting  the  forceps  care  must  be  taken  to  see  that  the  points  of  the 
beaks  are  inserted  into  the  buccal  and  lingual  sulci  formed  by  the  bifurcation 
of  the  roots.     The  application  of  force  should  be  a  forward  and  backward 

Fig,  694. 


Inferior  right  first  and  second  molar,  cow-horn  forceps. 

rocking  movement  until  the  tooth  is  loosened  in  its  alveolus,  when  the 
tooth  should  be  removed  by  traction  upivard. 

Seventh  Class. — The  superior  third  molars,  by  reason  of  their  position 
and  the  usual  backward  curvature  of  their  roots,  are  often  very  difficult  to 
extract.  When  the  root,  however,  is  straight,  their  extraction  is  a  very 
simple  matter  by  the  use  of  bayonet-shaped  forceps  having  simple  beaks 
made  to  fit  the  convexity  of  the  root  upon  the  buccal  and  lingual  surfaces. 
Fig.  695  shows  such  an  instrument  designed  for  use  upon  either  the  right 

Fig.  695. 


Bayonet-shaped  superior  third  molar  forceps  (universal). 

or  the  left  side  of  the  mouth.  The  positions  of  the  patient  and  the 
operator  and  the  application  of  force  are  the  same  as  for  the  extraction  of 
the  other  superior  molar  teeth.  Sometimes  these  teeth  are  large  and  have 
bifurcated  roots.  Under  such  circumstances  the  ordinary  superior  molar 
forceps  should  be  employed  for  their  extraction. 


612 


OPERATIVE    DENTISTRY. 


When  the  roots  of  these  teeth  curve  backward  the  ordinary  forceps 
nsed  for  the  extraction  of  the  third  molars  will  not  dislodge  them.  Special 
forceps  are  then  called  into  use.  To  meet  these  requirements  the  late  Dr. 
Physick  invented  the  forceps  shown  in  Fig.  696.  The  jaws  of  this  instru- 
ment represent  two  inclined  planes  looking  towards  each  other.  The  in- 
strument is  designed  to  act  as  a  double  wedge  when  placed  between  two 

Fig.  696. 


Superior  third  molar  forceps.     (Dr.  Physick.) 

resisting  bodies  and  force  is  applied  by  closing  the  handles.  In  the  ex- 
traction of  a  superior  third  molar  the  jaws  of  the  forceps  are  opened  and 
the  edges  placed  between  the  approximating  surfaces  of  the  second  and 
third  molars.  The  handles  of  the  forceps  are  then  closed  and  depressed, 
01'  rather  carried  towards  the  morsal  surfaces  of  the  superior  teeth :  the 

Fig.  697. 


Superior  third  molar,  extracting,  separating,  and  excising  forceps.    (Dr.  Stelhvagen.) 

double  wedge  of  the  jaws  thus  starts  the  tooth  from  its  alveolus  and  the 
depression  of  the  handles  carries  the  crown  backward,  dislodging  it  from 
its  alveolus.  Figs.  697  and  698  represent  instruments  designed  by  Dr. 
Stellwagen  for  the  combined  purpose  of  extracting  superior  and  inferior 
third  molars  and  excising  and  separating  roots.  The  principle  involved 
in  their  application  is  the  same  as  in  the  Physick  forceps. 


Inferior  third  molar,  extracting,  separating,  and  excising  forceps.     (Dr.  Stellwagen.) 


The  inferior  third  molars  have  usually  single  roots  which  curve  back- 
ward, but  occasionally  the  roots  are  multiple.  Under  these  circumstances 
they  can  usually  be  extracted  with  the  forceps  shown  in  Fig.  699,  but 


EXTRACTION    OF    TEETH. 


613 


when  the  root  is  curved  it  becomes  necessary  to  employ  the  Physick 
or  Stellwagen  forceps.  The  instrument  is  applied  as  for  the  removal  of 
the  superior  third  molars,  and  the  handles  are  closed  and  depressed.  This 
starts  the  tooth  from  its  alveolus,  tips  it  backward,  and  dislodges  it.  Care 
must  always  be  exercised  in  the  use  of  these  forceps  not  to  injure  the  tooth 
in  front  which  acts  as  the  fulcrum.     If  these  instruments  are  carelessly 

Fig.  699. 


Inferior  third  molar  forceps. 

handled  there  is  danger  of  fracturing  the  enamel,  thus  preparing  the  way 
for  the  establishment  of  caries  in  the  injured  tooth. 

Extraction  of  the  Roots  of  Teeth. — For  the  extraction  of  the  roots 
of  teeth  specially  devised  forceps  are  generally  employed :  these  have 
usually  thin,  narrow  beaks  that  can  be  insinuated  between  the  gum  and 

the  root. 

Fig.  700. 


Screw-forceps.     (Dr.  C.  H.  Dubs.) 

For  the  extraction  of  the  roots  of  the  six  superior  anterior  teeth  which 
are  so  decayed  as  to  present  thin,  frail  walls  the  Dubs  screw-forceps  (Fig. 
700)  and  the  Hullihen  screw-forceps  (Fig.  701)  are  the  best.  These  in- 
struments combine  the  dental  screw  with  the  narrow-beaked  forceps. 


Fig.  701. 


Screw-forceps.     (Dr.  S.  P.  Hullihen.) 


To  adjust  the  instrument  to  the  root  the  conical  screw  is  first  set  into 
the  pulp  cavity.  If  much  softened  dentin  is  present  this  should  first  be 
removed  and  the  screw  so  set  that  it  takes  hold  upon  the  sound  dentin. 
The  socket  between  the  jaws  of  the  forceps  is  then  placed  over  the  shaft  of 


614 


OPERATIVE    DENTISTRY. 


the  screw,  and  the  beaks  of  the  instrument  are  insinuated  between  the  gum 
and  the  root  and  carried  down  to  the  alveolus.  The  handles  are  then 
gripped  with  just  sufficient  force  to  prevent  the  instrument  from  slipping, 
and  the  root  is  rotated  to  the  right,— the  direction  in  which  the  screw  is 
get, — and  the  tooth  is  dislodged  from  its  alveolus. 

Fig.  702. 


Superior  anterior  root  forceps. 
Fig.  703. 


Superior  bicuspid  and  molar  root  forceps,  half-curve. 
Fig.  704. 


Superior  bicuspid  and  molar  root  forceps,  bayonet  shape.    (Dr.  B.  F.  Arrington. 

Fig.  705. 


Superior  root  forceps,  bayonet  shape.    (Dr,  Ambler  Tees.) 

Fig.  702  represents  a  straight  root  forceps  designed  for  the  extraction 
of  the  roots  of  the  six  superior  anterior  teeth,  which  can  be  used  in  all 
cases  where  the  root  is  not  so  badly  decayed  as  to  be  liable  to  crush  under 
the  pressure  necessary  to  keep  the  instrument  from  slipping  during  the 
extraction. 

For  the  extraction  of  the  superior  bicuspids,  the  half-curved  forceps 
represented  in  Fig.  703  will  be  found  most  admirable  instruments. 


EXTRACTION    OF   TEETH. 


615 


For  the  extraction  of  the  roots  of  the  superior  molars  there  is  no  better 
instrument  than  the  bayonet-shaped  root  forceps  shown  in  Figs.  704  and 
705. 

Great  care  should  be  exercised  in  the  extraction  of  the  roots  of  the  su- 
perior bicuspids  and  molars  not  to  force  them  upward  into  the  antrum  of 
Highmore,  as  under  such  circumstances  an  extended  surgical  operation 
becomes  necessary  for  their  removal,  involving  the  exsectiou  of  »■  con- 
siderable portion  of  the  floor  of  the  sinus. 

Fig.  706. 


Inferior  incisor,  cuspid,  and  bicuspid  root  forceps,  full  curve. 

For  the  extraction  of  the  roots  of  the  six  inferior  anterior  teeth  and 
the  bicuspids,  the  full-curved  lower-root  forceps  shown  in  Figs.  706  and 

Fig.  707. 


Inferior  root  forceps,  full  curve.    (Dr.  Ambler  Tees.) 


707  will  be  found  most  useful.  The  points  of  the  beaks  in  the  "Tees" 
forceps  are  made  thin  so  that  it  is  possible  to  insinuate  them  between  the 
root  and  the  gum. 


Fig.  708. 


•^WMtS^i^'si^.'J.'.'NVsV-.'aw 


Superior  alveolar  root  forceps,  bayonet  shape,  with  beaks  of  Dr.  Kell's  pattern. 

In  the  extraction  of  roots  in  the  superior  jaw  that  are  buried  in  the 
tissues,  the  "alveolar"  forceps  shown  in  Fig.  708  is  most  admirably 
adapted.  When  using  this  instrument  the  gum  should  be  incised  upon  the 
labial  and  lingual  surfaces  in  a  line  corresponding  to  the  long  axis  of  the 
root,  and  the  edges  of  the  gum  lifted  from  the  alveolar  process  upon  both 


616  OPERATIVE    DENTI-.TRY. 

sides  of  the  incisions.  The  beaks  of  the  forceps  may  now  be  insinuated 
between  the  gum  and  the  alveolar  process,  and  by  a  quick,  firm  pressure 
upon  the  handles,  the  alveolar  process  is  cut  through  and  the  root  removed. 

Fig.  709. 


Deciduous  inferior  universal  forceps.    (Dr,  M.  H.  Cryer.) 

In  the  extraction  of  the  roots  of  lower  molars  the  forceps  shown  in 
Fig.  709  is  most  admirably  adapted,  the  beaks  being  long,  thin,  and  narrow. 

Fig.  710. 


Inferior  alveolar  root  forceps.    (Dr.  J.  D.  Thomas.) 


The  ^'alveolar"  forceps  of  Dr.  Thomas  shown  in  Fig.  710  is  a  very  valu- 
able instrument  for  removing  such  roots  as  are  broken  off  below  the  gum. 


Fig.  711. 


Deciduous  superior  anterior  and  root  forceps. 


The  forceps  which  are  used  for  the  extraction  of  the  deciduous  teeth 
should  be  much  smaller  and  lighter  than  those  employed  for  the  extraction 


Fig.  712. 


Deciduous  superior  molar  forceps. 


of  the  permanent  teeth.     Three  pairs  are  sufficient  for  all  purposes.     Fig. 
711  is  for  the  extraction  of  the  six  superior  anterior  teeth  and  roots,  and 


Fig 

715. 

^n 

1 

1 

^^ 

1  ■ 

1 

1 

f  ^^B 

"1 

u 

1 

1 

L    V^Bi 

.  •'■>^- ■ 

^^^^ 

1 

1 

^ 

^^^^^^H 

M 

1 

1 

L^H 

iJ 

Fig.  716. 


Fig.  717.— After  Dr.  M.  H.  Cryer. 


Fig.  718.— After  Dr.  M.  H.  Cryer. 


Fig.  719.— After  Dr.  M.  H.  Cryer. 


Fig.  720.— After  Dr.  M.  H.  Cryer. 


YiG,  721.— After  Dr.  M.  H.  Cryer. 


Fig.  722. — Skiagraph  showing  misplaced  superior  cuspid  tooth. 


EXTEACTIOX    OF    TEETH. 


617 


Fig.  712  for  the  superior  molars.  Fig.  713  is  used  for  the  extraction  of  the 
six  inferior  anterior  teeth  and  for  the  inferior  molars.  The  '"universal" 
root  forceps  of  Dr.  M.  H.  Cryer  (Fig.  714j  are  also  admirable  instruments 
for  the  extraction  of  children's  teeth. 

Fig.  713. 


Deciduous  inferior  anterior  and  molar  forceps. 
Fig.  714. 


Deciduous  and  superior  universal  root  forceps.    (Dr.  M.  H.  Oyer.) 


DIFFICULTIES.    C03IPLICATIOXS,    AND   ACCLDEXTS. 

Anomalous  Teeth. — The  accompanying  illustrations  (Figs.  715  and 
716)  represent  some  of  the  more  common  deformities  of  the  teeth.  Figs. 
717,  718,  719,  720,  and  721,  which  are  kindly  loaned  to  the  ^vriter  by 
Dr.  ]M.  H.  Cryer,  show  some  of  the  more  common  malpositions  of  the 
teeth  which  complicate  the  operation  of  extraction,  and  often  render  it 
extremely  difficult  and  sometimes  hazardous.  Fig.  722  is  a  skiagraph 
showing  a  misplaced  superior  cuspid. 

The  cases  which  present  the  greatest  difficulties  are  the  teeth  having 
sharply  curved  roots,  hypercementosed  roots,  and  teeth  which  are  mis- 
placed and  impacted  in  the  jaws,  particularly  impacted  third  molars. 

Teeth  having  curved  or  hypercementosed  roots  offer  great  resistance  to 
the  force  applied  for  their  extraction.  In  the  former  the  curved  end  of 
the  root  is  often  fractured  and  left  in  its  alveolus,  while  in  the  latter  the 
alveolar  process  is  usually  fractured,  the  external  plate  giving  way  on  a 
line  with  the  alveoli,  in  the  endeavor  to  remove  the  tooth. 

The  former  accident  is,  however,  of  small  moment,  and  the  fractured 
portion  of  the  root  may  be  allowed  to  remain,  as  it  very  rarely  causes  any 
serious  after-trouble. 

The  fracture  of  the  alveolar  plate  is  more  serious,  and  if  neglected  or 
improperly  treated  may  result  in  necrosis.  If,  however,  the  fractured 
parts  are  brought  into  close  apposition  by  squeezing  them  together  with 
the  thumb  and  index  finger,  and  the  alveolus  frequently  irrigated  with 
antiseptic  solutions,  union  will  take  place  and  little  or  no  inflammation  or 
soreness  will  result  :  but  if,  on  the  other  hand,  the  fractured  parts  are 
allowed  to  remain  separated,  and  no  attention  is  paid  to  antiseptic  treat- 
ment, osteitis  and  necrosis  are  liable  to  occur. 


618 


OPERATIVE    DENTISTRY. 


Fig.  723. 


The  most  difficult  teeth  to  extract  are  the  imj)acted  third  molars,  which 
lie  more  or  less  horizontally  iu  the  jaw  and  impinge  upon  the  distal  sur- 
face of  the  crown  or  the  root  of  the  second 
molar,  as  shown  in  Fig.  723.  This  condition 
of  impaction  occurs  most  often  in  the  lower 
jaw.  When  the  crown  of  the  inferior  third 
molar  is  tilted  forward  so  that  it  impinges  upon 
the  distal  surface  of  the  second  molar  near  the 
cervix  or  lower  down  upon  the  root,  further 
progress  in  the  eruption  of  the  third  molar  is 
arrested,  and  irritation  and  inflammation  are 
liable  to  supervene,  making  it  necessary  to  ex- 
tract the  tooth.  In  order  to  accomplish  the 
removal  of  the  impacted  tooth,  it  becomes  neces- 
sary to  cut  away  with  corundum  disks  a  con- 
siderable portion  of  the  mesial  cusps  of  the 
third  molar.  After  this  has  been  done  the  tooth  may  be  grasped  with 
the  forceps  shown  in  Fig.  724  and  the  tooth  dislodged  from  its  alveolus. 
Or  it  may  be  dislodged  with  the  Physick  or  Stellwagen  '  ^  wisdom-tooth" 
forceps  (Fig.  725). 

Fig.  724. 


Inferior  left  second  and  third 
molars  as  they  were  located  in 
the  jaw. 


If,  however,  the  third  molar  has  not  erupted  or  only  shows  a  very  small 
portion  of  the  crown  through  the  gum,  and  the  tooth  occupies  a  hori- 
zontal position  in  the  jaw,  two  courses  only  can  be  suggested  for  its 
removal. 


Fig.  725. 


Physick  forceps. 


The  first  is  to  remove  the  second  molar,  as  this  makes  it  possible  to 
reach  the  third  molar  and  extract  it. 

The  second  is  to  dissect  the  gum  from  over  the  impacted  tooth,  chisel 
or  bur  away  the  bone  overlying  it,  and  then  lift  it  from  its  bed  with  an 
elevator  or  Physick  forceps. 

Operations  of  this  magnitude  should,  of  course,  be  made  under  a  gen- 
eral anaesthetic,  preferably  ether,  as  nitrous  oxide  anaesthesia  would  not 
last  long  enough  to  permit  the  operation  to  be  performed  painlessly. 


EXTRACTION    OP    TEETH.  619 

Other  teeth  than  the  third  molars  are  sometimes  impacted  in  the  jaws, 
and  require  surgical  operations  for  their  removal.  Those  which  are  most 
commonly  misplaced  are  the  superior  cuspids  (Fig.  721),  laterals,  and  bi- 
cuspids, and  the  inferior  bicuspids  and  cuspids,  their  relative  frequency, 
according  to  the  experience  of  the  writer,  being  in  the  order  named.  A 
good  general  rule  to  be  followed  in  operations  for  the  removal  of  impacted 
teeth  is  never  to  sacrifice  any  other  tooth  if  it  can  possibly  be  avoided. 

Fractures  of  the  Teeth. — In  the  extraction  of  teeth  that  are  badly 
decayed,  and  in  those  which  by  reason  of  abnormalities  in  form  or  position 
present  great  difficulties  in  their  removal,  fractures  of  the  crown  are  very 
liable  to  occur.  Under  such  circumstances  the  roots  should  be  immediately 
removed  with  instruments  suited  to  the  individual  case.  Sometimes,  how- 
ever, the  fracture  occurs  at  the  alveolar  margin  or  even  lower  down, 
making  the  removal  of  the  root  an  exceedingly  difficult  task,  except  by  the 
subalveolar  method  previously  described.  For  this  reason  the  alveolar 
forceps  shown  in  Figs.  708  and  710  should  be  found  in  every  complete 
extracting-case.  If  the  tooth  which  has  been  fractured  has  double  or 
multiple  roots,  it  often  becomes  necessary  to  divide  them  with  Stellwagen 
excising  forceps,  and  extract  each  root  separately. 

When  a  tooth  is  extracted,  fractured  or  crushed,  great  care  should  be 
taken  to  prevent  the  tooth  or  the  fragments  slipjjing  from  the  jaws  of  the 
forceps  and  falling  into  the  fauces,  and  becoming  arrested  at  the  entrance 
of  the  larynx  by  engaging  in  the  rima  glottidis,  or,  passing  downward, 
becoming  lodged  in  the  trachea  or  one  of  the  bronchi  (more  often  the 
right),  thus  preventing  or  impeding  the  admission  of  air  to  the  lungs  and 
causing  spasmodic  coughing,  dyspnoea,  and  the  more  serious  symptoms  of 
asphyxia. 

Whenever  a  foreign  substance  falls  into  the  fauces  the  body  of  the 
patient  should  immediately  be  thrown  forward,  and  the  index-finger  passed 
into  the  mouth  and  swept  around  the  fauces,  in  the  hope  of  removing  it. 
Failing  in  this,  the  patient's  body  should  be  inverted,  and  while  in  this 
position  the  back  vigorously  slapped  with  the  flat  of  the  hand.  If,  how- 
ever, the  foreign  body  has  passed  beyond  the  reach  of  the  fingers,  the 
laryngeal  forceps  may  be  employed  to  reach  it,  and  this  may  often  be  done 
if  it  has  not  passed  beyond  the  rima  glottidis.  If  the  foreign  body  has  en- 
tered the  trachea  or  become  lodged  in  a  bronchus,  an  immediate  trache- 
otomy is  the  only  means  of  relief.  Cases  of  this  character  may  prove  imme- 
diately fatal ;  while,  upon  the  other  hand,  if  the  fragment  of  tooth  is  small, 
and  has  passed  into  a  bronchus,  it  may  give  rise  to  no  immediate  symp- 
toms, but  later  the  patient  may  be  seized  with  violent  fits  of  coughing, 
dyspnoea,  bloody  expectoration,  and  finally  collapse  of  the  lung.  Miller 
records  a  case  of  suppuration  and  gangrene  of  the  lung  due  to  the  presence 
of  a  fragment  of  a  decayed  tooth. 

Impaction  of  a  tooth  or  a  fragment  of  a  tooth  or  other  foreign  body  in 
the  oesophagus  or  the  pyloric  orifice  of  the  stomach  sometimes  occurs,  and 
may  give  rise  in  the  former  to  symptoms  of  dysphagia,  and  in  the  latter  to 
gastric  dilatation  and  ulceration.  The  treatment  of  these  cases  belongs  to 
the  domain  of  general  surgery. 


620  OPERATIVE    DENTISTRY. 

Fractures  of  the  Alveolar  Process. — Fractures  of  tlie  alveolar  pro- 
cess are  frequently  the  result  of  the  extraction  of  the  teeth.  This  accident 
most  often  occurs  in  connection  with  the  superior  and  inferior  cuspids  and 
the  superior  molars. 

Teeth  which  stand  alone  are  the  most  liable  to  this  accident,  although 
it  may  occur  in  connection  with  the  extraction  of  any  tooth  if  the  process 
is  thin,  or  the  operation  is  roughly  or  unskilfully  iDcrformed,  or  the  roots 
are  malformed,  abnormally  large,  or,  as  in  the  molars,  widely  sj)read. 

Sometimes  the  attachment  of  the  alveolar  process  is  so  firm  that  the 
fractured  part  comes  away  with  the  tooth.  This  makes  an  ugly  wound  in 
the  gum,  which  may  require  two  or  three  stitches  to  bring  it  together. 

In  the  treatment  of  the  other  forms  of  fracture  of  the  alveolar  process 
the  simple  adjustment  of  the  fractured  parts  to  their  normal  position  and 
the  use  of  antiseptic  solutions  is  usually  all  that  is  required. 

Osteitis. — Inflammation  of  the  alveolar  process  is  a  frequent  sequel  of 
the  extraction  of  a  tooth  in  which  the  gums  and  process  have  been  bruised 
and  lacerated.  This  most  frequently  occurs  in  those  cases  where  the  tooth 
has  been  fractured  some  distance  beneath  the  margin  of  the  gum,  and  re- 
peated unsuccessful  attempts  have  been  made  to  remove  it. 

The  disease  is  attended  with  great  pain,  tenderness,  and  swelling  of  the 
surrounding  tissues,  suppuration,  and  sometimes  sloughing  of  the  soft  tis- 
sues and  death  of  the  bone. 

The  treatment  consists  in  the  free  use  of  antiseptic  and  stimulating 
lotions,  and  anodynes  to  control  the  pain. 

Gangrene  and  Necrosis. — These  conditions  frequently  follow  the 
unskilful  extraction  of  the  teeth,  and  are  the  result  of  crushing  the  soft 
tissues  in  the  one  case,  and  of  fractures,  injuries  which  cut  off  the  circula- 
tion, or  inflammation  in  the  other.  The  treatment  consists  in  removing 
all  dead  or  gangrenous  soft  tissue  with  scissors  or  knife,  washing  the  parts 
with  hydrogen  dioxide  to  remove  the  pus,  and  following  this  with  suitable 
antiseptic  lotions. 

^Necrosed  bone  should  not  be  disturbed  until  separation  has  taken  place 
between  the  dead  and  the  living  portions.  Meddlesome  treatment  only 
aggravates  the  inflammatory  process,  and  often  causes  an  extension  of  the 
disease  far  beyond  the  limits  which  were  previously  involved.  The  only 
treatment  to  be  recommended  is  that  comjprehended  under  the  term  anti- 
septic until  the  sequestrum  has  formed,  when  it  should  be  immediately 
removed,  and  the  parts  assisted  in  the  healing  process  by  thorough  cleanli- 
ness and  the  use  of  stimulating  and  antiseptic  solutions. 

Hemorrhage. — Hemorrhage  of  a  severe  and  continuous  type  often 
seriously  complicates  the  operation  of  tooth  extraction  in  those  individuals 
who  are  subjects  of  the  hemorrhagic  diathesis,  and  quite  a  number  of  cases 
are  on  record  in  which  the  hemorrhage  has  proved  fatal  after  every  effort 
had  been  made  to  arrest  it. 

Hemorrhage  may  be  primary,  recurrent,  or  secondary. 

Primary  hemorrhage  is  that  which  occurs  from  the  alveolus  immediately 
after  the  tooth  has  been  extracted,  and  usually  does  not  continue  for  more 
than  half  an  hour.     Sometimes,  however,  the  primary  hemorrhage  is  pro- 


EXTRACTION    OF    TEETH.  621 

fuse,  and  calls  for  treatment  for  its  control.  The  use  of  cold  water  or  ice- 
water,  or  water  as  hot  as  can  be  borne  in  the  mouth,  to  which  a  few  drops 
of  tincture  of  myrrh  or  aromatic  sulphuric  acid  have  been  added,  will  gen- 
erally be  sufficient  to  arrest  it. 

Becurrent  or  secondary  hemorrhage  is  that  which  follows  a  few  hours  aft-er 
the  primary  hemorrhage  has  ceased. 

This  form  of  hemorrhage  usually  comes  on  in  the  night  following  the 
day  upon  which  the  tooth  was  extracted,  or  following  the  sloughing  of  soft 
tissue  whose  vitality  had  been  destroyed  by  the  traumatism  or  by  the 
application  of  escharotic  styptics. 

Sometimes  the  hemorrhage  seems  to  be  confined  to  the  artery  which 
supplied  the  tooth,  the  blood  welling  up  from  the  apex  of  the  alveolus  ;  in 
other  cases  the  whole  inner  surface  of  the  alveolus  seems  to  take  part  in 
the  hemorrhage ;  while  in  others  it  may  be  confined  to  the  gum.  In  the 
more  severe  cases  in  which  there  is  a  marked  history  of  the  hemorrhagic 
diathesis,  the  blood  is  found  to  flow  not  only  from  the  dental  artery,  but 
from  the  inner  walls  of  the  alveolus  and  the  gums  as  well,  the  bleeding  in 
some  cases  being  so  profuse  that  the  patient  may  lose  from  a  pint  to  a 
quart  or  more  of  blood  in  a  few  hours,  causing  great  weakness  and  con- 
siderable alarm  and  anxiety  upon  the  part  of  the  patient  and  the  friends, 

In  examining  the  mouth  in  a  case  of  secondary  hemorrhage,  care  should 
be  taken  to  locate  the  exact  source  of  the  bleeding,  whether  it  is  from  the 
gum,  the  inner  wall  of  the  alveolus,  or  the  dental  artery. 

If  the  hemorrhage  comes  from  the  gum,  the  bleeding  point  may  be 
compressed  with  the  haemostatic  forceps,  or  any  little  vessel  picked  up  and 
torsion  applied.  If  this  does  not  arrest  the  bleeding,  a  compress  may  be 
made  of  warmed  gutta-percha  or  modelling  compound,  pressed  over  the 
part,  and  when  cooled  removed,  lined  with  lint  or  cotton,  saturated  with 
a  solution  of  tannic  acid  in  glycerol,  and  returned  to  the  mouth,  and  com- 
pression made  by  closing  the  jaws  upon  the  compress,  and  binding  them 
together  with  a  four- tailed  bandage.  When  the  hemorrhage  is  from  the 
socket  or  the  dental  artery,  the  case  should  be  treated  by  plugging  the 
alveolus.  This  may  be  done  by  forming  a  plug  to  fit  the  alveolus  from 
warmed  wax  or  modelling  compound,  made  in  the  form  of  a  cone,  a  little 
longer  and  larger  than  the  tooth  which  had  been  removed,  and  pressing  it 
firmly  into  the  alveolus.  The  large  end  of  the  plug  should  rise  a  little 
above  the  crowns  of  the  adjacent  teeth,  so  that  when  the  jaws  are  closed 
pressure  will  be  brought  to  bear  upon  the  plug.  When  cooled  it  can  be 
removed,  the  alveolus  cleared  of  blood-clots  and  washed  with  ice-water 
charged  with  a  suitable  antiseptic,  and  the  plug  returned  to  the  alve- 
olus after  it  has  been  rolled  in  tannic  acid  or  dipped  in  the  tannic  acid 
and  glycerol  solution.  The  jaws  should  then  be  closed  ujdou  the  plug  and 
maintained  in  that  position  by  the  adjustment  of  the  four-tailed  bandage. 
The  writer  considers  this  method  very  much  better  from  the  aseptic 
stand-point  than  the  old  method  of  packing  the  alveolus  with  cotton,  lint, 
or  strips  of  bandage,  as  the  liability  to  septic  infection  and  suppurative 
inflammation  is  greatly  reduced. 

When  the  hemorrhage  comes  from  the  alveoli  of  several  contiguous 


622  OPERATIVE    DENTISTRY. 

teeth,  each  alveolus  should  be  treated  by  the  method  described,  and  then 
all  may  be  bound  together,  while  they  are  in  place,  by  another  piece  of 
warmed  modelling  compound  pressed  down  over  the  exposed  ends  of  the 
plugs  and  moulded  to  the  gums  upon  the  buccal  and  lingual  surfaces,  and 
when  nearly  cooled  the  jaws  may  be  closed  upon  it  sufficiently  to  take  an 
impression  of  the  opposing  teeth. 

After  the  mass  has  thoroughly  cooled  it  may  be  removed  altogether,  the 
plugs  treated  as  just  described,  and  the  whole  returned  to  its  place  and 
retained  in  position  by  the  closed  jaws  and  the  four-tailed  bandage. 

If  there  is  time  to  do  so,  and  the  facilities  are  at  hand,  a  metal  or  vul- 
canite splint  may  be  constructed  from  an  impression  taken  of  the  parts. 
When  this  method  is  pursued,  the  alveoli  should  be  plugged  with  modelling 
comi^ound  and  the  splint  used  to  force  the  plugs  into  place  and  produce 
compression  upon  the  gums. 

A  few  cases  are  on  record  in  which,  after  arresting  the  hemorrhage 
from  the  alveolus,  oozing  of  blood  from  the  mucous  surface  of  the  gums 
occurred,  as  is  sometimes  seen  in  scorbutus  and  purpura  Jicemorrliagica. 

In  these  cases  it  becomes  necessary  to  secure  compression  over  a  con- 
siderable area  of  the  gums,  and  this  can  best  be  accomplished  by  the  metal 
splint  just  described. 

Before  applying  the  splint  it  should  be  lined  with  cotton  or  lint,  and 
saturated  with  a  non-irritating  styptic.  The  use  of  escharotic  styi^tics, 
like  the  perchloride  of  iron,  nitric  acid,  and  chromic  acid,  should  never 
be  permitted,  as  they  cause  sloughing  of  the  soft  tissues  and  secondary 
hemorrhage,  which  is  more  difficult  to  control  than  the  former  condition, 
by  reason  of  the  greater  surface  involved  as  a  result  of  the  escharotic 
action  of  the  remedy. 

After  the  compresses  have  been  applied,  the  patient  should  be  instructed 
to  keep  as  quiet  as  possible,  maintain  the  sitting  posture,  and  avoid  all  hot 
fluids  and  stimulants.  Liquid  diet  should  be  ordered, — milk,  beef  extracts, 
broths,  and  soups. 

In  those  cases  in  which  there  has  been  great  loss  of  blood,  stimulants 
may  be  administered  and  the  body  kept  warm.  The  hot  foot-bath  is  some- 
times serviceable  in  diverting  the  blood  to  the  lower  extremities  and  re- 
lieving arterial  tension  in  the  upper  part  of  the  body. 

To  the  constitutional  remedies  which  have  been  mentioned  as  useful  in 
controlling  the  tendency  to  hemorrhage  in  those  persons  having  the 
hemorrhagic  diathesis, — viz.,  gallic  acid  combined  with  opium,  and  the 
fluid  extract  of  ergot, — the  perchloride  of  iron  may  be  added, — 

R     Liq.  ferri  perchlor. ,  m.  x  ; 

Aq.  destilL,  f^j.     M. 
To  be  taken  every  two  hours. 

Fatal  syncope  has  been  known  to  follow  the  extraction  of  a  tooth  in  cases 
in  which  there  was  no  functional  or  organic  disease  of  the  heart. 

Tomes  calls  attention  to  two  such  cases  that  have  been  placed  on  record. 
A  similar  case  came  under  the  knowledge  of  the  writer,  as  occurring  in 


EXTRACTION    OF    TEETH.  623 

the  practice  of  a  friend.  In  this  case,  however,  there  was  fatty  degenera- 
tion of  the  heart,  as  shown  by  the  post-mortem  examination.  The  patient 
was  a  lady  about  sixty  years  of  age,  and  was  apparently  in  good  health. 
The  dentist  seated  her  in  the  chair  preparatory  to  the  operation,  and 
turned  to  his  case  to  select  the  instrument,  when  she  fainted  and  could  not 
be  resuscitated,  death  occurring  almost  instantaneously. 


INDEX. 


Abbot  on  resorption  of  teeth,  76 
Abrasion,  causes  of,  371 
definition  of,  368,  371 
treatment  of,  372 
Abscess,  dento-alveolar,  see  Dento-alveolar 

abscess 
Acids  and  alkalies,  influence  of,  on  growth 

of  bacteria,  90,  91 
Albuminoids  and  mouth  bacteria  in  caries, 

151 
Alcohol,  use  of,  in  hypersensitive  dentin, 

190 
Alexander's  method  of  making  gold  inlays, 

347,  348 
Alloys,  composition  of,  314-319 

making  of,  319,  320 
Allport's  pyorrhoea  alveolaris  instruments, 

547 
Aluminum,  use  of,  in  alloys,  314,  315 
Alveolar  abscess  associated  with  deciduous 
teeth,  488 
chronic,  485 

treatment  of,  486,  487 
Amalgam-carriers,  326 
Amalgam,  definition  of,  296 
fillings,  finishing  of,  330 
indications  for  use  of,  321,  322 
-instruments,  326,  327 
manipulation  of,  325-327 
nature  and  properties  of,  298 
setting  of,  298,  299 
wafering  of,  327 
Amalgams,  annealing  of,  309,  310 
color  of,  312 
composition  of,  296,  297 
conductivity  of,  312,  313 
contraction  and  expansion  of,  299-310 
flow  of,  306 
mixing  of,  323-325 
stability  of,  310,  311 
washing  of,  325 
Amelification,  39 
Ameloblasts,  32,  34,  35 


Ammonia,  use  of,  in  treating  gold,  256, 

257 
Anaesthesia,  Bon  will's  method,  216 
definition  of,  578 
electro-cocaine,  207-211 
general,  586-594 

examination  of  patient  for,  590, 

591 
Hewitt's  method,  589,  590 
precautions  against  accidents,  591, 
592 
local,  578-586 

Letamendi's  method,  580,  581 
Richardson's  method,  579,  580 
with  chloretone,  584,  585 
with  cocaine,  581-583 
with  eucaine,  584 
with  tropacocaine,  583,  584 
use  of,  in  hyiDersensitive  dentin,  187, 
214-216 
Anaesthetic,  see  Anaesthesia 
Anatomy,   classification,   and  description 

of  the  teeth,  1 
Animal  fungi  (mycetozoa),  85 
Anomalous  teeth,  617 
Anterior  teeth,  separation  of,  175 
Antikamnia,  use  of,  in  pericementitis,  465 
Antimony,  use  of,  in  alloys,  314 
Approximal  cavities,  preparation  of,  225- 

228,  230,  231 
Arkansas  stones,  use  of,  in  formation  of 

margins,  249 
Arkovy  on  action  of  arsenic  upon  dental 

pulp,  426,  427 
Arnott  on  local  anaesthesia,  581 
Arsenic,  physical  effects  of,  on  dental  pulp 
424,  425 
use  of,  in  devitalizing  pulps,  423,  427- 
429 
Atropia  sulphas,  use  of,  in  hypersensitive 

dentin,  188 
Attrition,  causes  of,  369,  370 
definition  of,  368 
pathology  of,  370 
treatment  of,  370 
40  625 


626 


INDEX. 


Bacilli,  classified,  86,  88,  89 
Bacillus,  anthrax,  87 

buccalis  maximus,  93,  97,  99 
Bacteria,  action  of  antiseptics  on,  169 
aerobic,  86 
aerogenic,  87 
anaerobic,  86 
chromogenic,  87 
classification  of,  86 
conditions    necessary  for  growth  of, 

154 
effect  of,  on  integrity  of  dental  tissues, 

101,  102 
functions  of,  87 
in  caries,  153 

influence  of  heat  and  moisture  on,  91 
in  mouth,  92,  148 
multiplication  of,  89,  90,  98 
pathogenic,  87,  88,  92 

action  of,  102 
saprogenic,  87,  101 
zymogenic,  87,  101 
Bacteriology,  definition  of,  83 
Balsam  del  deserto,  use  of,  489 
Barbed  nerve-broaches,  430 
Batteries,  electric,  description  of,  200,  201 
Bibulous  paper,  exclusion  of  moisture  by, 

178,  179 
Bichloride  of  mercury  as  an  antiseptic,  169 
use  of,  in  implantation,  498,  500 
in  transplantation,  495 
Bicuspids,  cavities  (compound)  of,  prepa- 
ration of,  231-233 
(simple)  on  approximal  surfaces, 
preparation  of,  227,  228 
on  exposed  surfaces,   prepa- 
ration of,  220-225 
inferior,  15,  16 
superior,  12-15 
Bing's  pluggers,  259 
Bismuth,  use  of,  in  alloys,  315 
Black  on  chronic  pulpitis,  415 
on  erosion,  366 

on  pathology  of  pulp  hypersemia,  381 
on  resorption  of  teeth,  76 
on  secondary  dentin,  422 
on  suppuration  of  pulp,  410 
Black's  method  of  treating  acute  alveolar 
abscesses,  483,  484 
one-two-three  mixture,  463 
Bleaching  discolored  teeth,  446-458 

cataphoric  method,  465-458 
chlorine  method,  451 
dioxide  methods,  452-455 


Bleaching    discolored    teeth,    sulphurous 
anhydride  method,  455 
Truman  method,  451,  452 
preparation  of  tooth  for,  449,  450 
Blind  abscesses,  drainage  of,  483 
Blood-serum  therapy   in  poisoning  from 

bacteria,  90 
Boll  on  nerve-endings  in  pulp,  44 
Boric  acid,  use  of,  in  implantation,  499 
Brophy's  band  matrices,  284 
Bud  fungi,  description  of,  85 
Bunge  on  analysis  of  proteids,  447 
Burnishers  for  finishing  fillings,  288,  289 
Burs,  plug-finishing,  forms  of,  189 


Cadmium,  use  of,  in  alloys,  315,  316 
Calcic  deposits  upon  the  teeth,  521 
Calcification,  definition  of,  34 
Calcoglobulin,  36,  44 
Calcospherites,  32,  35,  51 
Callahan's    method    of    enlarging    pulp- 
canals,  436 
Cannabis  indica,  use  of,  in  hypersensitive 

dentin,  188 
Caoutchouc,  separating  teeth  with,  177 
Carbohydrates,  fermentation  of,  101,  102 
groups  of,  150 
in  the  mouth,  148 
Carbolic  acid,  use  of,  in  devitalizing  pulps, 
424 
in  disinfecting  cavities,  246 
in  hypersensitive  dentin,  190, 
191 
Caries,  abnormal  oral  secretions  as  predis- 
ing  cause  of,  123,  124 
central,  origin  of,  140 
chemical  theory  of,  140-143 
constitutional  predisposing  causes  of, 

124-131 
decalcification  of,  156,  157 
definition  of,  115 
diagnosis  of,  163,  164 
diagnostic  of  inherited  syphilis,  129, 

130 
electro-chemical  theory  of,  143,  144 
etiology  of,  123 
excision  of,  172,  173 
expansion  of  tubuli  in,  157-160 
forms  of,  140 
germ  theory  of,  144 
historic  facts,  115,  116,  135-148 
humoral  theory  of,  136 
immunity  in,  154,  155 
inflammatory  theory  of,  136-139 


INDEX. 


627 


Caries,  influence  of  continued  fevers  on,  130 
of  exanthemata  on,  130 
of  inherited  disease  on,  129,  130 

irregularities  as  predisposing  cause  of, 
132,  133 

local  predisposing  causes  of,  131-134 

of  bone,  135 

of  cementum,  60 

of  dentin,  153 

penetration  of,  160 

peripheric,  origin  and  forms  of,  140 

phenomena  of,  in  dentin,  155,  156 

pigmentation  of,  156,  157 

predisposing  causes  of,  123-134 

prevalence  of,  in  present  civilization, 
118,  119 

prognosis  of,  164,  165 

prophylactic  treatment  of,  166,  170 

putrefaction  theory  of,  140 

silver  nitrate  in  treatment  of,  171,  172 

stages  of,  161,  162 

structural  defects  as  predisposing  cause 
of,  131,  1S2 

susceptibility  in,  154,  155 

symptoms  of,  162,  163 

syphilis,  hereditary,  and,  129,  130 

tables  relative  to,  121,  ]22 

theories  of,  136 

therapeutic  treatment  of,  171 

traumatic    injuries    as     predisposing 
cause  of,  132 

varieties  of,  161 

worm  theory  of,  139,  140 
Carnivora,  definition  of,  1 
Caseation,  definition  of,  401 
Cataphoresis,  definition  of,  193 

resistance  of  tissues  in,  211,  212 

substances  used  in,  196 
Cataphoric  appliances,  456-458 

bleaching  method,  455-458 
Cavities,  classification  of,  217,  218 

guarding  of,  with  amalgam,  328,  329 

margins  of,  formation  of,  248 

opening  of,  235,  244 

preparation  of,  212,  234,  235,  354 

removal  of  decay  in,  244 

retentive  shape  of,  246-248 
Cementification,  35,  53 
Cementoblasts,  35 

Cement  spatulas  and  mixing-slab,  338 
Cementum,  52 

caries  of,  160 

histological  composition  of,  52 
Chappell's  pluggers,  265 
Chloretone  as  a  local  anaesthetic,  584,  585 
in  hypersensitive  dentin,  188 


Chloretone  in  lining  cavities,  332 
Chlorinated  soda  as  a  bleaching  agent,  452 
Chlorine  as  a  bleaching  agent,  451 
Chloroform,  use  of,  in  hypersensitive  den- 
tin, 216 
Chloro-percha,  use  of,  in  filling  pulp-canals, 

442 
Cleansing   teeth,  instructing   patients  in, 

167 
Climatic  influences  predisposing  to  caries, 

126,  127 
Cloves,  oil  of,  use  of,  in  disinfecting  cavi- 
ties, 246 
in  hypersensitive  dentin,  190 
Cocaine  as  a  local  anaesthetic,  581-586 
in  cataphoresis,  194,  208,  212 
in  hypersensitive  dentin,  188 
in  phagedenic  pericementitis,  577 
poisoning,  symptoms  of,  585,  586 
treatment  of,  586 
Cocci,  85,  86 

Conducting  cords  and  tips,  electric,  207 
Constitutional  treatment  of  primary  mor- 
bid dentition,  70,  71 
Copper  amalgam,  antiseptic  action  of,  313 
as  a  filling-material,  329,  330 
manipulation  of,  317,  318 
preparation  of,  316,  317 
electric  conductivity  of,  202 
use  of,  in  alloys,  316 
Corundum  wheels,  forms  of,  290 
Cotton,  exclusion  of  moisture  by,  178,  179 
filling  pulp-canals  with,  440 
separation  of  teeth  with,  176 
sterilization  of,  176 
Cushing's     pj'orrhoea    alveolaris     instru- 
ments, 548 
Cuspids,  cavities  in,  compound,  prepara- 
tion of,  229-231 
simple    approximal,    preparation 
of,  225-227 
exposed,  preparation  of,  218- 
220 
inferior,  11,  12 
superior,  9-11 
Custer's  electric  oven,  352 

D 

Darby-Perry  pluggers,  265 

Darby's  capsicum  and  sinapin  plasters,  use 

of,  in  pericementitis,  464 
Decalcification  in  caries,  156,  157 
Decay,  percentage  of,  in  deciduous  teeth, 
120 
in  permanent  teeth,  120 


628 


INDEX. 


Deciduous  teeth,  2,  24,  25,  73 

extraction  of,  indications  for,  595, 

596 
exuviation  of,  73,  74 
formula  for,  2 
resorption  of,  74,  75 
retention  of,  causes  of,  74 
Dental  groove,  primary,  29 
secondary,  29 
ridge,  30 
tissues,  calcification  of,  34 

chemical  composition  of,  54 
histology  of,  34 
Dentin,  caries  in,  155,  156 

chemical  composition  of,  42 
decalcification  of,  244-246 
definition  of,  41,  184 
discoloration  of,  429,  430 
pathology  of,  447-449 
globules,  47 

hypersensitiveness  of,  184 
causes  of,  184,  185 
treatment  of,  186,  187,  214 
anaesthetic,  214-216 
chemical,  188-192 
palliative,  187,  188 
matrix  of,  42 
papillae  of,  30,  31 
Dentinal    fibres,    disorganization    of,    in 
caries,  159,  160 
fibrils,  function  of,  44 
sheaths,  44 
tubuli,  43 
tumors,  39 
Dentinification,  theories  of,  35,  48 
Dentition,  59 

primary,  causes  of  irritation,  65,  66 
constitutional  treatment  of,  70,  71 
eruptive  process  of,  60-62 
local  symptoms  of,  69,  70 
morbid,  64 

complications    arising    from, 

67,  68 
treatment  of,    constitutional, 
70,  71 
local,  71 

gum-lancing,  71,  72 
mortality  from,  68,  69 
periods  of  completed  root  forma- 
tion of,  64 
of  eruption  of,  59 
secondary,  symptoms  of,  79 
Dento-alveolar  abscess,  causes  of,  474-476 
chronic,  479 
definition  of,  474 
differential  diagnosis  of,  480 


Dento-alveolar  abscess,  location  of,  477-479 
pathology  of,  476,  477 
prognosis  of,  480-482 
pus  formation  in,  477 
symptoms  and  diagnosis  of,  479, 

480 
treatment  of,  constitutional,  482 

local,  482-485 
varieties  of,  476 
Denudation  (erosion),  definition  of,  359 
De  Trey's  solila  gold,  269 
Diapedesis  (exudation),  definition  of,  398 
Dislocation  of  teeth,  501 
Disto-labial  cavities,  preparation  of,  229 
Disto-lingual  cavities,  preparation  of,  229, 

230 
Disto-morsal  cavities,  preparation  of,  231 
Donaldson's     bristles     and      pulp-canal 

cleansers,  435 
Dover's  powder,  use  of,  in  pericementitis, 

465 
Dynamo-current  controllers,  206 

E 

Electric  gold  annealers,  271 

hot-air  syringe,  190 

mouth-lamp.  111 
Electricity,  "generation  of,  199,  200 

induced,  classes  of,  202 

transmission  of,  202 

units  of  measurement  in,  203,  204 

use  of,  in  phagedenic  pericementitis, 
577 
Electrolysis,  anodal,  197,  198 

cathodal,  198,  199 
Elevators  for  extraction,  603 
Elliot's  clamp  and  forceps,  182 
Enamel,  calcification  of,  39,  40 

caries  of,  152,  153 

chemical  composition  of,  38 

-chisels,  use  of,  in  opening  cavities, 
242-244,  249 

definition  of,  36 

-globules,  41 

-organ,  30 

blood-supply  of,  40 
invagination  of,  31 

-prisms,  37 

transverse  striations  of,  37 
Endogenous  spore  formation,  98 
Engine-burs,  use  of,  in  opening  cavities, 

241,  242,  249 
Epiderm,  development  of,  27 
Epithelial  band,  30 

cells,  26 


INDEX. 


629 


Epithelial  lamina,  30 

tissue,  evolution  of,  26 
Erosion  of  teeth,  definition  of,  359 
etiology  of,  360-367 
pathology  of,  367 
treatment  of,  367,  368 
Eruption  of  teeth,  forces  producing,  62 
Essential  oils,  use  of,  in  devitalizing  pulps, 

424 
Ether,  administration  of,  215,  592-594 
as  a  local  anaesthetic,  579,  580 
use  of,  in  hypersensitive  dentin,  215, 
216 
Ethyl  chloride  as  a  local  anaesthetic,  581 
Eucaine  as  a  local  anaesthetic,  584 
Evolution  of  epithelial  tissue,  26 
of  jaws,  29 
of  teeth,  30 
Examination  of  teeth,  technique  of,  112- 

114 
Excavating  in  hypersensitive  dentin,  186, 

187 
Excavators,  forms  of,  226,  245 
Excision,  effects  of,  174 

of  caries,  172,  173 
Explorers,  110 

forms  of,  111 
Extraction  of  dental  roots,  613-617 
of  teeth,  595-623 

conditions  unfavorable  to,  597-599 
fractures  of  alveolar  process  in, 

617,  620 
hemorrhage  following,  620-623 
indications  for,  595-597 
instruments  used  in,  600 
of  impacted  third  molars,  618 
of  inferior  central  and  lateral  in- 
cisors, 605,  606 
first  and  second  molars,  609- 
611 
of  superior  and  inferior  bicuspids, 
607,  608 
cuspids,  606,  607 
third  molars,  611-613 
central  and  lateral    incisors, 
/  604,  605 

first  and  second  molars,  508, 
509 


Filling  compound  cavities  with  gold,  278- 
283 
materials  used  in,  251 
points  to  be  observed  in,  250,  251 
simple  cavities  with  gold,  272-278 

Fission  fungi,  84 


Fistula,  dento-alveolar,  treatment  of,  487 
Flagg  on   physical   effects  of   arsenic  on 

pulps,  425,  426 
Flagg' s    gutta-percha  softener    and    tool- 
heater,  334 
wafering  pliers  for  amalgam,  324 
Floss-silk,  112,  167 
Forceps,  aseptic,  602 

for  extraction,  604-618 
Fractures  of  alveolar  process  in  extraction. 
617,  620 
of  teeth,  classification  of,  505 
in  extraction,  619 
union  aftef ,  507,  508 


Gangrena  oris,  70 

Gangrene,  as  result  of  extraction,  620 
Gates-Glidden  drills,  435 
Gauze,  exclusion  of  moisture  by,  178,  179 
Gingivae  (gums),  histology  of,  58 
Gingivitis,  definition  of,  541 
Gnathodynamometer,  definition  of,  239 
Gold,  annealing  of,  270,  271 
as  a  filling-material,  251 
cohesive,  description  of,  256 

foil,  description  and  forms  of,  262, 
263 
introduction  of,  263 
crystal  mat,  in  filling,  269 

preparation  of,  268 
cylinders,  non-cohesive,  258-260 
fillings,  finishing  of,  287,  288 

repairing  of,  293-295 
flow  of,  under  stress,  253,  255 
-foil  (non-cohesive),  method  of  intro- 
duction of,  258,  259 
properties  of,  255-257 
use  of,  in  filling  pulp-canals,  439 
moss  fibre,  in  filling,  269,  270 
non-cohesive,  description  of,  256,  257 
-pluggers,  259,  260,  264,  265,  267 
ropes  and  ribbons  in  filling,  261 
strength  of,  252 
use  of,  in  alloys,  318 
Gold-and-platinum  foil,  270 
Goodsir's  theory  of  evolution  of  teeth,  28 
Gouty  pericementitis,  467,  550-567 
differential  diagnosis  of,  469 
prognosis  of,  469 
symptoms  and  diagnosis  of,  468, 

469 
treatment  of,  469 
Granulation-tissue  defined,  477 
Green  stains  upon  the  teeth,  521 
treatment  of,  521 


630 


INDEX. 


Guilford's  matrix,  284 
Gum-retractor,  272 
Gums  (gingivse),  58 

Gutta-percha  as  a  capping  for  pulps,  333, 
418 

as  a  filling-material,  330,  331,  441 

as  a  permanent  filling,  333 

fillings,  finishing  of,  336 

in  filling  root-canals,  332,  441 , 

manipulation  of,  335,  336 

physical  characteristics  of,  331,  332 

separating  teeth  with,  177 

softening,  333-335 

H 

Heematogenic  calcic  pericementitis,  550-567 

Hsematoidin,  448,  449 

Hsemosiderin,  449 

Harlan  on  bleaching  teeth,  453 

Heated  air  in  treatment  of  hypersensitive 

dentin,  189,  190 
Hemorrhage  following  extraction,  620-623 
treatment  of,  621,  622 

from  lancing  gums,  73 
Herbst's  burnishers  for  gold,  264 

method  of  making  glass  inlays,  351 
of  packing  non-cohesive  gold,  261 
Heredity,  influence  of,  on  caries,  129 
Hewitt's  method  of  general  anaesthesia, 

589,  590 
Hill's  stopping,  330 
How's  cervix  clamp,  181,  272 

inlay  burs,  351 

thermoscopic  heater  for  gutta-percha, 
335 
Huber  on  nerve-endings  in  pulp,  47 
Hutchinson  on  syphilitic  teeth,  129,  130 
Hydrochloric  acid,  use  of,    in  enlarging 

canals,  436 
Hydrogen  dioxide  as  bleaching  agent,  452, 

453,  456,  457 
Hypersemia  of  pulp,  373,  385 
Hypercementosis,  causes  of,  513,  514 

pathology  of,  514,  515 

symptoms  and  diagnosis  of,  516,  517 

treatment  of,  517 
Hyperplasia,  definition  of,  401 
Hypersensitive  dentin,  162,  184 
Hypertrophy,  definition  of,  513 
Hypoderm,  development  of,  27 


Immunity,  definition  of,  103 
Implantation,  definition  of,  496 
instruments  used  in,  498,  499 


Implantation,  operation  of,  498-500 

preparation  of  tooth  for,    see  Trans- 
plantation 
prognosis  of,  500 
requirements  for,  497 
Implanted  teeth,  resorption  of,  77 
Incisors,  cavities  in,  compound,  229-231 
simple,  218-220,  225-227 
inferior,  8,  9 
superior,  4-8 
Incremental  lines,  48 
Infectious  diseases,  104 
Inflammation,  definition  of,  397 
forms  of,  401,  402 
physical  signs  of,  397 
tissue  changes  in,  399-402 
Inflammatory  phenomena,  table  of,  402 
Inhaler  for  ether  administration,  Allis's, 
593 
Lente's,  593 
Inlays,  amalgam,  348,  349 
definition  of,  346 
glass,  making  of,  351,  352 
gold,  making  of,  347 
porcelain,  cavity  prtiparation  for,  354 
finishing  of,  358 
manipulation  of,  354-358 
methods  of  using,  349-351 
taking  impression  of  cavities  for, 

355,  356 
setting  of,  357,  358 
Inostosis,    definition  and    description  of, 

515,  516 
Instruments  for  cohesive  foil,  263-268 
for  non-cohesive  foil,  259 
for  setting  screw-posts,  248 
sterilization  of,  103,  105 
used  in  examinations,  109-112 
Interglobular  spaces,  47 
Irregularities  of  permanent  teeth,  causes 

of,  80-82 
Irritants  classified,  397,  398 
Ivory's  rubber-dam  clamps,  181 


Jack  on  pseudo-exposures,  417,  418 
Jack's  matrices  and  forceps,  284 
Jaws,  evolution  of,  29 

growth  of,  63 
Jenkins  on  porcelain  inlays,  353 
Jodococcus  vaginatus,  93,  94,  99 

K 

Kirk  on  discoloration  in  devitalized  teeth, 

446 
Kirk's  method  of  bleaching  teeth,  455 


INDEX. 


631 


Labial  cavities,  preparation  of,  218,  219 
Lactic  acid,  production  of,  in  the  mouth, 

150 
Laminae,  48 

Lancing  gums  in  primary  dentition,  71,  72 
Leptothrix,  96 

buccalis  maxima,  93,  97,  99 
gigantea,  95 
innominata,  92,  93,  97 
racemosa,  development  of,  stages  of, 
96-99 
Leptotrichse,  definition  of,  86 
Letamendi's  method  of  local  anaesthesia, 

580,  581 
Leucomaines,  103 
Libby's  rubber-dam  clamp,  272 
Lines  of  Schreger,  38 
Lingual  cavities  in  teeth,  preparation  of, 

219,  220,  224,  225 
Listerine,  use  of,  in  disinfecting  cavities, 

246 
Local  anaesthetics,  578-586 
Local  treatment  of  primary  morbid  den- 
tition, 71 
Luxation,  definition  of,  501 

M 

Mallet,  Abbott  automatic,  267 

Bonwill  electro-magnetic,  266,  267 

mechanical,  267,  268 
hand,  forms  of,  264 
Snow  and  Lewis  automatic,  266 
Malpighian  layer,  28 
Mandrels,  forms  of,  293 
Matrices,  forms  of,  283-285 

use  of,  in  amalgam  fillings,  222,  323 
in  gold  fillings,  283 
McQuillen  on  bleaching  teeth,  453 
Mechanical  separation  of  teeth,  175,  176 
Meckel's  cartilage,  30 
Medicaments  used  in  treatment  of   root 

canals,  436-438 
Membrana  eboris,  32,  48 
Mental  strain  in  children  predisposing  to 

caries,  128,  129 
Mercurial  pericementitis,  471,  473 
Mercuric  chloride,  use  of,  in  phagedenic 

pericementitis,  576 
Mercury  bichloride,  use  of,  in  disinfecting 

cavities,  246 
Mesio-labial  cavities,  preparation  of,  229 
Mesio-lingual  cavities,  preparation  of,  229 
Mesio-morsal  cavities,  preparation  of,  231 
Mesoderm,  development  of,  27 


Methyl  chloride  as  a  local  anaesthetic,  581 
Micrococci,  classification  of,  89 

description  of,  88 
Micro-organisms,  84 
Miller  on  mummification  of  pulps,  444 
Miller's  classification  of  fungi,  84 
Milliamperemeters,  use  of,  206 
Mirrors,  forms  of,  109,  110 
Miscegenation,  influence  of,  on  caries,  127, 

128 
Mitchell's  electric  furnace,  352 
Molars,  cavities  in,  compound,  231-233 
simple,  220-225,  227,  228 

inferior,  21-24 
deciduous,  25 

superior,  17-21 
deciduous,  25 
Morphia  acetas  in  hypersensitive  dentin, 

187 
Morphine,  use  of,  in  devitalizing  pulps, 

424 
Morsal  edge  cavities,  preparation  of,  220 
Mould  fungi,  description  of,  84,  85 
Mouth  and  teeth,  sterilization  of,  104 

examination  of,  107 

-mirrors,  sterilization  of,  105,  106 

-props,  592,  601 
Mucous  glands,  secretion  of,  523 
Mummification  of  dental  pulp,  443-445 
Mummifying  pastes,  formulae  for,  444 

N 

Napkins,  exclusion  of  moisture  by,  178 
Nasmyth's  membrane,  38 

origin  and  function  of,  54,  55 
Nausea  caused  by  rubber  dam,  treatment 

of,  183 
Necrobiosis,  definition  of,  518 
Necrosis  as  result  of  extraction,  620 
causes  of  519,  520 
definition  of,  401,  518 
of  cementum,  519,  520 
treatment  of,  520 
Nerve-extractors,  430-436 
Neumann,  sheaths  of,  in  caries,  159 
Nitrous  oxide  as  a  general  anaesthetic,  586- 
590 
use  of,  in  hypersensitive  dentin, 
215 
Noma,  70 

O 

Obturation,  definition  of,  250 
Occlusal  cavities,  preparation  of,  221-223 
Occluso-buccal  cavities,  preparation  of,  232 
-distal  cavities,  preparation  of,  231,  232 


€32 


INDEX. 


Occluso-lingual  cavities,  preparation  of,  233 
-mesial  cavities,  preparation   of,  231, 

232 
-mesio-distal  cavities,  preparation  of, 
233 
Odontitis  infantum,  70 
Odontoblasts,  32,  34,  35,  48,  422 
Operator,  position  of,  107 

sterilizing  hands  of,  104 
Ossification,  35 

Osteitis  as  result  of  extraction,  620 
Osteodentin,  description  of,  394 
Ottolengui  on  use  of  antiseptics  in  mouth, 

170 
Ottolengui' s  method  of  preparing  gutta- 
percha points,  441 
rubber-dam  clamp,  181 
Oxidizing  agents,  forms  of,  451 
Oxyhsemoglobin,  definition  of,  447 


Palladium,  use  of,  in  alloys,  318 
Parasites  classified,  84 
Parotid  gland,  excretion  of,  523 
Parr  teeth-separator,  112,  175,  176 
Pathogenic  bacteria,  diseases  caused  by, 
96 
mouth  bacteria,  92 
Patient,  position  of,  107 
Peppermint,  oil  of,  use  of,  in  disinfecting 

cavities,  246 
Pepsin,  use  of,  in  extirpation  of  pulps,  430 
Pericemental  membrane,  56 
blood-supply  of,  57 
functions  of,  57 
nerve-supply  of,  58 
origin  and  composition  of,  57 
Pericementitis,  causes  of,  459^61 
chronic,  symptoms  of,  466 
treatment  of,  466,  467 
definition  of,  450 
differential  diagnosis  of,  462 
general  non-septic,  467 
gouty,  550-567 

hgematogenic    calcic,    definition    and 
causes  of,  550-558 
pathology  and  morbid  anat- 
omy of,  558-562 
prognosis  and  treatment  of, 

562-567 
symptoms  and  diagnosis  of, 

562 
varieties  of,  558 
mercurial,  471,  473 
prognosis  of,  473 


Pericementitis,  mercurial,  symptoms  and 
diagnosis  of,  472,  473 
treatment  of,  473 
pathology  of,  461 
phagedenic,  causes  of,  568 
definition  of,  568 
differential  diagnosis  of,  573 
pathology  of,  570 
prognosis  of,  573 
symptoms  and  diagnosis  of,  572, 

573 
treatment  of,  573-577 
prognosis  of,  462,  463 
ptyalogenic  calcic,  causes  of,  541,  542 
pathology  and  morbid  anat- 

of,  542-544 
prognosis  of,  545 
symptoms   and  diagnosis   of, 

544,  545 
treatment  of,  545-549 
scorbutic,  470,  471 

symptoms  and  diagnosis  of,  470, 

471 
treatment  of,  471 
subacute  and  chronic,  465,  466 
symptoms  and  diagnosis  of,  461,  462 
treatment  of,  constitutional,  464,  465 

local,  463,  464 
tubercular,  469,  470 
Pericementum,   diseases    of,   classification 

of,  459 
Permanent  teeth,  calcification  of,  78 
eruption  of,  77 
order  of,  79 
extraction  of,  indications  for,  596, 

597 
follicles  of,  33 
formula  for,  2 

irregularities  in  eruption,  causes 
of,  80 
local,  80,  82 
resorption  of  roots  of,  causes  of, 
509,  510 
pathology  of,  510-512 
prognosis  and  treatment 

of,  512 
symptoms  and  diagnosis 
of,  512 
Perry  separator,  112,  175,  176 
Perry's  hot-air  syringe,  189 
Phagedenic  pericementitis,  568-577 
Phagocytes,  476,  477 
Physiologic  resorption,  77 
Platinum,  use  of,  in  alloys,  319 
Plug-finishing  files  and  trimmers,  291,  292 
Porcelain  inlays,  352-354,  356,  357 


INDEX. 


633 


Potassium  bromide,  use  of,  in  pericemen- 
titis, 465 
Primary  epithelial  cord,  30 
Prophylactic  treatment  of  caries,  166,  170 
Proteids,  analysis  of,  447,  448 
Protists,  definition  of,  85 
Protozoa,  definition  of,  85 
Ptomaines,  88,  102 

Ptyalogenic  calcic  pericementitis,  541-549 
Pulp,  calcification  of  tissues  of,  392 
-canal  pluggers,  439 
-canals,  enlarging  of,  435-438 
filling  of,  438-443 
medicaments  used  in  treatment  of, 

436-438 
preparation  and  treatment  of,  432- 

434 
treatment    of,    in    pericementitis, 
463 
-capping,  418,  419 

-chamber  and  canals,  opening  of,  434, 
435 
calcic  formations  within,  classifi- 
cation of,  390 
devitalization  and  extirpation  of,  423, 

424,  430 
exposure  of,  complete,  treatment  of, 
423 
false,  treatment  of,  416,  417 
incomplete,  description  of,  419 
due  to  traumatism,  421 
prognosis  of,  420,  421 
symptoms  and  treatment  of, 
419,  420 
stages  of,  416 
hypersemia  of,  causes  and  forms  of, 
375-378 
definition  of,  373 
from   constitutional   causes,   385- 

38 
from  internal  local  causes,  384 
pathology  of,  379 
prognosis  of,  382,  383 
symptoms  and  diagnosis  of,  378, 

379,  387 
treatment  of,  383-385,  387,  428 
irritation  of,  373,  374,  396 
mummification  of,  443-445 
plethora  of,  definition  of,  386 
suppuration  of,  407-410 
forms  of,  409,  410 
symptoms  and  diagnosis  of,  410, 

411 
treatment  of,  412 
Pulpitis,  acute  circumscribed,  403,  404 
diffuse,  404 


Pulpitis,  acute,  prognosis  of,  405,  406 

symptoms  and  diagnosis  of,  404, 

405 
treatment  of,  406,  407 
chronic,  forms  of,  412 
definition  of,  397 
etiology  of,  402,  403 
pathology  of,  403 
Pulpless  teeth,  431,  432 
Pulp-stones   (nodular  calcifications),  391, 

392 
Pyogenic  bacteria,  83,  91,  92 

action  of,  102 
Pyorrhoea  alveolaris,  74,  539 

bacterial  origin  of,  539-541 
constitutional  origin  of,  531-537 
definition  of,  530 
etiology  of,  531 
instruments  used  in,  547,  548 
local  origin  of,  537-539 
synonymes,  530 

treatment    of,    545-549,    563-567, 
573-577 


Quinine,  use  of,  in  pericementitis,  465 


Recurrent  hemorrhage,  621 
Replantation  of  teeth,  490-493 

in  phagedenic  pericementitis,  576 
preparation  of  tooth  for,  491 
Replanted  teeth,  resorption  of,  77 
Resorption  of  teeth,  76,  77,  509 
Retzius  on  nerve-endings  in  pulp,  46 
Rheostats,  forms  of,  204-206 
Richardson's  method  of  local  anaesthesia, 

579,  580 
Rigolene  as  a  local  anaesthetic,  580 
Robinson's  remedy  in  hypersentive  dentin, 

192 
Root  development  of  teeth,  48 
Royce  plugger-points,  265 
Rubber  cups  for  polishing,  290 
dam,  adjustment  of,  180-182 
clamps,  172,  173,  181 
exclusion  of  moisture  by,  177, 179, 

180 
forms  of,  179 
punch,  182 
shield,  183 
sterilization  of,  106 


634 


INDEX. 


Saliva,  chemical  reaction  of,  523 
composition  of,  521,  522 
description  of,  133 

ejectors,  exclusion  of  moisture  by,  179 
Salivary  calculi,  composition  of,  523,  524 
instruments  used  in  removal  of, 

528 
pathologic  effects  of,  526,  527 
treatment  of,  527-529 
varieties  of,  524-527 
Salol  and  paraffin,  use  of,  in  filling  pulp- 
canals,  442,  443 
Schizomycetes,  description  of,  84 
Scorbutic  pericementitis,  470,  471 
Secondary  dentin,  391,  421,  422 
dentition,  symptoms  of,  79 
separation  of  teeth,  methods  of,  112, 
175 
Septic  infection,  102 
intoxication,  102 
pulp-canals,  treatment  of,  431 
Sharpey's  fibres,  160 
Silver,  electric  conductivity  of,  202 
nitrate,  use  of,  in  caries,  171,  172 

in  hypersensitive  dentin,  192 
-tin  alloys,  composition  of,  299,  307, 

308,  311 
use  of,  in  alloys,  319 
Sodium  dioxide  as  a  bleaching  agent,  453- 

455 
Spirilla,  definition  of,  86,  89 
Spirillum  sputigenum,  94,  99 
Spirochsete  dentium,  94 
Sponge-grafting,    use    of,    in    phagedenic 

pericementitis,  577 
Staphylococcus,  description  of,  86 
Sterilization  of    instruments  and  hands, 
103,  104 
of  mouth,  antiseptics  used  in,  104 
technique  of,  104 
Stomatitis,  catarrhal,  70 

ulcerous,  70 
Stomatoscope,  111 
Stones  for  finishing  fillings,  290 
Stratum  intermedium,  39 
Streptococcus,  description  of,  86 
Strise  of  Retzius,  37 
Sublingual  glands,  secretions  of,  523 
Submaxillary  glands,  secretions  of,  523 
Sulphuric  acid  as  a  bleaching  agent,  455 
use  of,  in  enlarging  canals,  436 
Syphilitic  teeth,  129,  130 
Syringe  electrode,  213 
water-,  use  of,  241 


Tannic  acid,  use  of,  in  hemorrhage,  621 
Tape  for  separating  teeth,  176 
Teeth,  anatomy  of,  3 

architectural  design  of,  4 
blood-supply  of,  618 
calcic  deposits  upon,  521 
character  of,  in  gouty  subjects,  557 
deciduous,  24,  25 
development  of,  26 
dislocation  of,  classes  of,  501 
prognosis  of,  504 
treatment  of,  501-504 
eruption  of,  59 
evolution  of,  30 
examination  of,  107 
extraction  of,  595-623 
fractured,  union  of,  507,  508 
fractures  of,  classification  of,  505 
in  extraction,  619 
treatment  of,  506,  507 
green  stains  upon,  521 
implantation  of,  496-500 
morphology  of,  26 
number  and  classification  of,  1 
origin  of,  26 

permanent,  see  Permanent  teeth 
replantation  of,  490-493 
transplantation  of,  494-496 
Temperaments,  162,  163 
Temporary  stopping'  uses  of,  332 
Tin  and  gold  in  combination  as  filling- 
material,  286,  287 
methods     of     introduction     of, 
287 
-foil,  forms  of,  285 
therapeutic  action  of,  286 
use  of,  in  alloys,  319 

in  filling  pulp-canals,  439,  440 
Tobolt's  laryngeal  forceps,  601 
Tomes,  granular  layer  of,  47 

zone  of,  156 
Tooth,  apical  foramen  of,  4 
cervix  of,  4 
crown  of,  4 
morsal  edge  of,  4 
-paste,  formula  of,  168 
-powder,  formula  of,  168 
pulp-chamber  of,  4 
-pulp,  definition  of,  55 

histological  composition  of,  55 
root  of,  4 
Toxines,  102 
Transplantation  of  teeth,  494 

method  of  union  in,  496 


INDEX. 


635 


Transplantation  of  teeth,  prognosis  of,  496 
preparation  of  tooth  for,  see  Eeplanta- 
tion 
Transplanted  teeth,  resorption  of,  77 
Tropacocaine  as  a  local  anaesthetic,  583, 

584 
Truman  on  secondary  dentin,  422 
Truman's  method  of  bleaching  teeth,  451, 

452 
Tubercular  pericementitis,  469,  470 
Tubuli,  bacteria  in,  159 

expansion  of,  in  caries,  157,  158 
Turnkey,  use  of,  in  extraction,  602 


Varney's  gold-pluggers,  264 

Varnishes,  use  of,  in  lining  cavities,  344, 
345 

Veratria  in  hypersensitive  dentin,  187 

Von  Beust's  method  of  preparing  gutta- 
percha points,  442 


W 

"Warren's  screw-gag,  601 
Watts' s  crystal  gold,  268 
Weagant's  method  of  using  porcelain  in- 
laj^s,  350,  351 
trephines  for  inlays,  351 
Webb's  pluggers,  264 
Wedges  for  separating  teeth,  175,  176 
Weston's  milliamperemeter,  207 
Williams  on  leptothrix,  99,  100 
Witzel's  method  of  mummifying  pulps, 

443 
Wood  points,  use  of,  in  filling  pulp-canals, 
440 
polishing-points,  289 


Woodward's  double  screw  matrices,  285 

separator,  175 
Wright's  method  of  bleaching  teeth,  452 
Wurtz  on  analysis  of  proteids,  448 


Younger  on  implantation,  496 


Zinc  cements  in  lining  cavities,  327,  328 
varieties  of,  336 
chloride  in  hypersensitive  dentin,  191, 

192 
oxychloride  as  a  capping-material,  418, 
419 
as  a  fiUing-material,  336,  337,  339 
characteristics  and  properties  of, 

338,  339 
mixing  of,  337,  338 
preparation  of,  337 
use  of,  in  filling  discolored  teeth, 
452,  454,  455 
in  filling  pulp-canals,  440,  441 
oxyphosphate  as  a  capping-material, 
419 
crushing  stress  of,  343,  344 
in  hypersensitive  dentin,  191 
mixing  and  introduction  of,  341, 

342 
penetration  of  moisture  in,  343 
preparation  of,  339-341 
properties  and  uses  of,  341 
shrinkage  and  expansion  of,  342, 
343 
oxysulphate    as    a   capping-material, 

344,  418 
use  of,  in  alloys,  319 


THE   END. 


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